Abstract
We review comparative studies of infant habituation and dishabituation performance focusing on preterm infants. Habituation refers to cognitive encoding, and dishabituation refers to discrimination and memory. If habituation and dishabituation constitute basic information-processing skills, and preterm infants suffer cognitive disadvantages, then preterms should show diminished habituation and dishabituation performance. Our review provides evidence that preterm infants’ habituation and dishabituation are impoverished relative to term infants. On the whole, effect sizes indicated that the differences between preterms and terms are of a medium magnitude. We also find that preterms’ performance is moderated by risk factors, stimulus materials, procedural variables, and age. These factors need to be taken into account in the construction of tests in which habituation-dishabituation tasks are employed. Overall, the habituation-dishabituation paradigm presents a promising approach in the diagnosis of cognitive status and development in preterm infants.
Keywords: habituation, dishabituation, preterm development, cognitive development, meta-analysis
1. Introduction
1.1 Epidemiology of Preterm Birth
The term infant is delivered about 38 to 42 weeks after the mother’s last menstrual period. The World Health Organization (WHO) defines preterm birth as delivery before 37 completed weeks of gestation (and low birth weight if born under 2500 g). Rates of preterm birth vary around 10% and with country. Among the 4 million new births each year in the United States, approximately 12.3% of children are born too early – that is, approximately 1 in 8 babies (Martin et al., 2007). Among European countries, preterm birth rates vary widely, ranging from 5.3% in Lithuania to 11.4% in Austria. In Germany, the preterm birth rate amounts to 8.9% (EURO-PERISTAT Project, 2008; Macfarlane & Blondel, 2005). Overall, according to Beck et al. (2009), the highest rates of preterm birth are in North America and Africa (10.6% and 11.9%), and the lowest are in Europe (6.2%). Moreover, wherever trend data are available, rates of preterm birth are increasing. For example, the premature birth rate in the United States increased by more than 30% between 1981 and 2003 (Martin et al., 2007). Women pregnant through certain infertility treatments, poor women, and those under age 16 or over 35 have increased risk; even single babies conceived by in vitro fertilization are more likely to be preterm (Jackson, Gibson, Wu, & Croughan, 2004). Other factors that are associated with preterm birth include poor diet, maternal stress, lack of prenatal care and smoking, increased use of caesarean deliveries, and growth in multiple birth rates as well as ongoing technological advances in neonatal care that promote the viability of very small infants (Behrman & Butler, 2006; Davidoff et al., 2006; Goldenberg, Culhane, Iams, & Romero, 2008; Hamilton, Martin, & Sutton, 2004). Moutquin (2003) described the etiological heterogeneity of preterm birth leading to taxonomy of three main categories: medically indicated (iatrogenic) preterm birth, preterm premature rupture of membranes (PPROM), and spontaneous (idiopathic) preterm birth. The cause of spontaneous preterm birth tends to be unknown, and therefore it is difficult to predict and prevent (Behrman & Butler, 2006; Steer, 2005).
Preterm infants are commonly classified according to gestational age, the period of time between conception and birth (the number of weeks that the baby has been in utero) as well as birth weight. Postmenstrual age (PA) is gestational age plus chronological age, the time elapsed between birth and date of assessment. Age of preterms is usually described in terms of corrected age (Wilson & Cradock, 2004), denoting the age of the child from the expected date of delivery. Corrected age is determined by subtracting the number of weeks born before 40 weeks of gestation from the child’s chronological age. Gestational age is normally trichotomized as “mild preterm birth” (32–36 weeks gestational age); “very preterm birth” (28–31 weeks gestational age); and “extremely preterm birth” (< 28 weeks gestational age). Birth weight is trichotomized as “low birth weight (LBW)” 1500 – 2499 g; “very low birth weight” (VLBW) 1000 – 1499 g; “extremely low birth weight” (ELBW) ≤ 1000 g).
1.2 Medical Issues
Preterm low birth-weight babies have average hospital stays of 45 to 50 days, and between one-third and one-half experience one or more rehospitalizations during the first 3 years of life (Behrman & Butler, 2006). Serious health problems and developmental delays are more pronounced among very preterm and very low birth weight babies, who account for between 14% and 15% of all preterm, low-birth-weight births in the United States. In Europe, very preterm births account for about 1% of all births. The Institute of Medicine (Behrman & Butler, 2006) estimated the annual societal economic burden associated with preterm birth in the United States to be $26.2 billion in 2005 (or $51,600 per infant born preterm). In Germany, the cost difference between a term and a preterm delivery amounts to about €10,550 (Kirschner, Halle, & Pogonke, 2009).
Very preterm, very low birth-weight infants are at increased risk for brain complications, such as intraventricular hemorrhage (IVH) and periventricular leukomalacia, both of which are associated with significant developmental delay (Allin, 2006). Intraventricular hemorrhage is defined by bleeding in areas surrounding the lateral cerebral ventricles (Luciana, 2003). IVH is classified into one of four grades with Grade 1 being the mildest degree of severity. IVH can injure the hippocampus, a site of recognition memory (e.g., Aylward, 2005; Kirwan, Wixted, & Squire, 2008). Beauchamp et al. (2008) found that very preterm infants with relatively small hippocampal volumes displayed working memory deficits at age 2 years. Reduced myelination has also been found in preterm, as compared to term, infants’ white matter (Mewes et al., 2006; Woodward, Mogridge, Wells, Inder, 2004; Volpe, 2003). Even preterms without early brain injury are characterized by a potential disruption in the development of brain structures such as the corpus callosum (Aylward, 2005). Birth before 28 to 30 weeks gestation can result in lung tissue which is very fragile, increasing the risk that this tissue will be injured. Injured lung tissue tends to trap air, collapse, or fill with mucus. Respiratory distress syndrome (RDS) is associated with infants born younger than 32 weeks of gestational age, with 80% of infants born younger than 27 weeks’ gestation developing RDS (Behrman & Butler, 2006; Verma, 1995). Sometimes bronchopulmonary dysplasia (BPD) or chronic lung disease (CLD) follow RDS in preterm infants (Vanhatalo, Ekblad, Kero, & Erkkola, 1994). Respiratory distress syndrome is indexed by the length of time on oxygen.
Bhutta and Anand (2001) linked cumulative brain injuries to observed cognitive deficits. Neuropsychological studies provide evidence that long-term cognitive and behavioral outcomes of preterm birth range from severe impairments, such as language disorders, to less severe problems, such as mild cognitive delays or visuomotor difficulties (e.g., Case-Smith, Butcher, & Reed, 1998; Feldman, 2009; Moster, Lie, & Markestad, 2008). Wood et al. (2000) found about 50% of their cohort of 30-month-old preterm infants from the United Kingdom and Ireland had a disability in mental or psychomotor development, neuromotor function, or sensory and communication function domains with approximately 25% reaching criteria for severe disability. In turn, these disabilities were predictive of child outcome at 6 years when the rate of moderate or severe disability observed was 46% (Marlow, Wolke, Bracewell, & Samara, 2005). Anderson and Doyle (2003) reported that 55% of survivors born very preterm and extremely low birth weight in Australia exhibited clinically significant neurobehavioral impairment in middle childhood. Lefebvre, Glorieux, and St-Laurent-Gagnon (1996) reported a 30% overall incidence of abnormality in their cohort of Canadian preterm infants (born between 23 and 29 weeks gestation). Therefore, across countries findings have shown similar rates of atypical development, which have tended to occur in approximately 50% of extremely preterm infants.
Neurodevelopmental outcome effects appear to be much stronger in preterms who experience multiple risk factors including IVH, RDS, and a birth weight of less than 1500 g (e.g., Foulder-Hughes & Cooke, 2003; Wolke, Ratschinski, Ohrt, & Riegel, 1994). Dividing all samples that are included in our review into preterms with IVH or RDS problems, preterms with other disturbances (excluding IVH or RDS problems), and preterms without additional risk factors, is confounded with both differences in birth weight and, to a lesser extent, gestational age. All preterm samples with no additional problems are characterized by low birth weight and by gestational ages between about 30 and 36 weeks (see Table 2). Most preterm samples with IVH or RDS have very low birth weight and a gestational age between about 30 and 33 weeks (see Table 4). The group of preterms with complications other than IVH or RDS (see Table 4) is, for the most part, comparable to the group of preterms with no additional complications in both birth weight and gestational age. Separation of these two groups is, thus, probably artificial. It is possible that preterms who are classified in the present review as non-risk de facto suffer similar complications as preterms with additional complications (except IVH or RDS problems), but that depictions of these complications were omitted in the research reports.
Table 2.
Authors | Preterms | Terms | ||||
---|---|---|---|---|---|---|
n | GA1M (SD) | PA2M (SD) | BW3M (SD) | Sample Characteristics | n | |
Bonin, Pomerleau, & Malcuit (1998) measurement 1 |
34 | 32.15 (2.36) | 48.71 | 1,712.35 (392.71) | 36 | |
measurement 2 | 34 | 57.0 | 36 | |||
measurement 3 | 34 | 65.71 | 36 | |||
Fagan, Fantz, & Miranda (1971, quoted from Fantz, Fagan, & Miranda (1975) | 44 | 36.2 | 45–58; infants were tested every two weeks | 48 | ||
Field, Woodson, D. Cohen, Greenberg, Garcia, & Collins (1983) | 48 | 35.4 | 35.4 (no age correction) | 2,700 | 48 | |
Friedman, Jacobs, & Werthmann (1981) | 36 | 33.7 (2.2) | 40.1 | 1,819.5 (387.8) | The initial sample consisted of 45 preterms and 23 terms. | 15 |
Kopp, Sigman, Parmelee, & Jeffrey (1975) | 25 | 32.6 | 40.1 (0.52) | < 2,500 | 254 | |
Mash, Quinn, Dobson, & Narter (1998) study 1 |
16 | 31.7 (2.0) | 55.5 | 1,741.7 (460.2) | 16 | |
study 2 | see study 1 | see study 1 | see study 1 | see study 1 | 16 | |
Rose (1980) study 1 |
18 | 33.0 | 67.7 | 1,633.3 (347.2) | 18 | |
study 2 | 18 | 32.7 | 67.7 | 1,582 (263.9) | Infants received tactual, proprioceptive, and vestibular stimulation within the first weeks after birth. | 18 |
Rose (1983) study 1 |
20 | 34.5 | 68.9 | 1,802 (449.6) | 20 | |
study 2 | 20 | 34.6 | 96.3 | 1,820 (380.7) | 20 | |
Rose, Gottfried, & Bridger (1978) study 1 |
25–27 | 32.6 (2.5) | 94 | < 2,000 | The initial sample consisted of 28 preterms and 39 middle-class terms. | 23–25 |
study 2 | see study 1 | see study 1 | see study 1 | see study 1 | Terms were from lower-class families. | 27 |
Rose, Gottfried, & Bridger (1979) study 1 |
18 | 33.4 (1.6) | 68.6 | 1,610 (270.7) | 18 | |
study 2 | 18 | 33.2 (2.4) | 93 | 1,738 (249.6) | 18 | |
Sigman, Kopp, Littman, & Parmelee (1977) | 28 | 33.2 (3.1) | 40 (0.7) | 1,926.7 (434.5) | 28 | |
Sigman & Parmelee (1974) | 20 | 33.6 | 58 | 1,927.8 | 20 |
Notes. Standard deviations are given in parentheses.
Gestational age in weeks.
Postmenstrual age in weeks.
Birth weight in grams.
Data for the term infants are taken from Sigman, Kopp, Parmelee, & Jeffrey (1973).
Table 4.
Authors | Preterms | Terms | ||||
---|---|---|---|---|---|---|
n | GA1M (SD) | PA2M (SD) | BW3M (SD) | Sample Characteristics | n | |
Caron & Caron (1981; see also Caron, Caron, & Glass, 1983) measurement 1 |
22 | 33 | 52 | 1,620 | Participants had been in intensive care for complications of varying severity. | 22 |
measurement 2 | 22 | 58 | 22 | |||
measurement 3 | 22 | 61 | 22 | |||
measurement 4 | 20 | 64 | 22 | |||
Cohen (1981) measurement 1/study 1 |
11 | 33 | 60 | 1,956 | All but 4 infants had the hyaline membrane disease and required respiratory assistance; 5 had seizures, 1 had severe hypocalcemia, and 1 had congenital heart disease. Number of participants is unequal from assessment to assessment, because only several infants were tested repeatedly. |
12 lower-class infants |
measurement 1/study 2 | see study 1 | see study 1 | see study 1 | see study 1 | 12 middle-class infants | |
measurement 2 | 9 | 29 | 73 | 1,963 | 14 lower-class infants | |
measurement 3 | 38 | 31 | 89 | 1662 | 15 lower-class infants | |
Holmes, Nagy Reich, Gyurke (1989) measurement 1 |
not available | 33.4 (2.6) | 48.66 | 2,134 | Ill preterm infants. | not available |
measurement 2 | not available | 57.33 | 7 | |||
measurement 3 | not available | 65.98 | not available | |||
Landry, Leslie, Fletcher, & Francis (1985) study 1 |
14 | 30.29 (1.82) | 70.31 | 1,229.29 (181.30) | Infants with intraventricular hemorrhage and respiratory distress syndrome. | 10 |
study 2 | 9 | 30.33 (2.50) | 70.31 | 1,296.33 (259.68) | Infants without intraventricular hemorrhage and with respiratory distress syndrome. | 10 |
Lewis (1981) study 1 |
22 | “overhelming” premature infants | not given | not given | Infants with respiratory distress syndrome, with asphyxia or a combination of the two. | not given |
study 2 | 19 | see study 1 | not given | not given | see study 1. | not given |
study 3 | 30 | see study 1 | not given | not given | see study 1. | not given |
Millar, Weir, & Supramiam (1991) study 1 |
14 | 33.5 | 73.34 | 2,420 | Infants with respiratory complications which required oxygen therapy during the neonatal period. | 13 |
study 2 | 15 | 36.7 | 75.01 | 2,850 | Infants with non-respiratory neonatal risks: either infection, or cardiac anomalies, or minor physical anomalies, or toxaemia or pre-eclampsia, or neonatal jaundice. | 13 |
study 3 | 19 | 32.9 | 69.70 | 1,990 | see study 1. | 14 |
study 4 | 16 | 36.4 | 69.39 | 2,610 | see study 2. | 14 |
Ortiz-Mantilla, Choudhoury, Leevers, & Benasich (2008) measurement 1 |
314 | 29.6 | 69 | 976 (245.5) | The study started with 32 preterms and 32 terms in each age group. At birth, 17 infants weighted below 1,000 grams, 15 infants weighted between 1,000 grams and 1,500 grams. 19 infants were considered “low risk” according to their Nursery Neurobiological Risk Score, 4 were classified as “intermediate risk”, and 3 were classified as “high risk.” 6 children had intraventricular hemorrhage: Grade 1: 2; Grade 2: 2; Grade 3: 2. |
234 |
measurement 2 | 204 | 82 | 264 | |||
Rose, Feldman, & Jankowski (2001) measurement 1 |
50 | 29.6 (2.9) (7-month-olds) | 62.6 | 1,107.9 (282.6) (7-month-olds) | Longitudinal study started with 50 preterms. At measurements 2 and 3, additional babies were tested. Small for gestational age: 33.9% of the sample. Respiratory distress syndrome: 50.8%. Intraventricular hemorrhage: no bleeding: 50.8%; Grade 1: 16.9%; Grade 2: 20.3%; Grade 3: 11.9%. 91% had very low birth weights (< 1,500 grams), and 39% had extremely low birth weights (< 1,000 grams). |
153 |
measurement 2 | 59 | 74.4 | 144 | |||
measurement 3 | 56 | 97.6 | 126 | |||
Rose, Feldman, & Jankowski (2002) measurement 1 |
39 | 29.6 (2.9) (7-month- olds) | 62.6 | 1,107.9 (282.6) (7-month-olds) | see Rose, Feldman, & Jankowski (2001). | 134 |
measurement 2 | 48 | 71.0 | 128 | |||
measurement 3 | 55 | 93.6 | 117 | |||
Rose, Feldman, McCarton, & Wolfson (1988) | 40 (habituation) 36 (dishabituation) |
31.4 | 70.31 | 1,183.9 (210.9) | The study started with 56 preterms and 43 terms. For 40 preterms, habituation data were available. For 36 of the preterms, dishabituation data were available. 76% of the preterm sample were diagnosed as having respiratory distress syndrome. | 39 |
Ross, Tesman, Auld, & Nass (1992) study 1 |
30 | 30.2 | 73.5 | 1,431.1 (226) | Grade 1 or grade 2 hemorrhage (subendymal and intraventricular hemorrhage). | 30 |
study 2 | 30 | 30.5 | 73.8 | 1,494.7 (256) | Infants with no hemorrhage. | 30 |
Spungen, Kurtzberg, & Vaugham (1985) | 17 | 32.0 (3.1) | 40.02 (1.3) | 1,219 (354) | Low birth weight infants. 38% of the sample displayed deviant visual-following; 25% had abnormal tone. | 25 |
Notes. Standard deviations are given in parentheses.
Gestational age in weeks.
Postmenstrual age in weeks.
Birth weight in grams.
n is reconstructed from the respective publication.
1.3 Preterm Cognitive Prognosis
Premature birth is a major cause of developmental delay. In recent years, concern has shifted from the survival of preterm (and low birth weight) infants toward their long-term prognosis and quality of life. Despite improved survival rates, disability rates associated with preterm status have remained stable, leading to more survivors with disabilities and impairments as an absolute number (Anderson, Doyle, & the Victorian Infant Collaborative Study Group, 2003; Goldberg & DiVitto, 1983; Hintz, Kendrick, Vohr, Poole & Higgins, 2005; Lefebvre et al., 1996; Vohr, Wright, Poole, & McDonald for the NICHD Neonatal Research Network Follow-Up Study, 2005; Zwicker & Harris, 2008).
Poor long-term outcomes have been documented in preterm infants in various domains of development, including motor, sensory, cognitive, and behavioral (for reviews see Anderson & Doyle, 2008; Bhutta, Cleves, Casey, Cradock, & Anand, 2002; Salt & Redshaw, 2006; Zwicker & Harris, 2008). Vohr et al. (2000) found that ~50% of a cohort of extremely preterm and extremely low birth weight infants in the United States had abnormal neurodevelopmental and sensory assessments. Similar incidence in cohorts of preterm and low birth weight infants have been found in various countries (Anderson & Doyle, 2003; Khan et al., 2006; Lefebvre et al., 1996; Marlow et al., 2005; Wood et al., 2000).
In their meta-analysis, Bhutta et al. (2002; see also Bhutta, 2004) pointed out that preterm birth is associated with lower cognitive test scores at school age, a conclusion supported by Anderson and Doyle’s (2008) review. Impairments in preterms’ (recognition) memory performance have been documented, not only in the first year of life (e.g., Rose, Feldman, & Jankowski, 2001), but in later childhood as well (e.g., Beauchamp et al., 2008; Isaacs et al., 2000; Luciana, Lindeke, Georgieff, Mills, & Nelson, 1999; Rose & Feldman, 1995). Furthermore, gestational age and birth weight appear to be directly proportional to cognitive performance: the younger the gestational age and lower the birth weight, the lower the cognitive score. Scores on the Mental Development Index (MDI) of the Bayley Scales of Infant Development have been shown to be significantly lower in preterm, as compared to term, children from 18 months to 30 months (Foster-Cohen, Edgin, Champion, & Woodward, 2007; Hintz et al., 2005; Khan et al., 2006; Rose, Feldman, Jankowski & van Rossem, 2005; Vohr et al., 2000; Wood et al., 2000). Similar results have been reported for the Griffiths Mental Development Scales (Lefebvre et al., 1996). Cognitive deficits, as documented by IQ scores, have been shown to persist into the early school years (6 to 7 years; Anderson, Doyle & the Victorian Infant Collaborative Study Group, 2003; Marlow et al., 2005; Wiener, Rider, Oppel, Fischer, & Harper, 1965), middle childhood (12 years; Constable et al., 2008), and adolescence and young adulthood (15 and 19.5 years; Allin et al., 2007, 2008).
Cognitive development is impaired not only in high-risk, but also in low-risk preterms, that is in preterms without neurological deficits such as cerebral palsy or mental retardation or hearing loss (e.g. Atkinson & Braddick, 2007; Caravale, Tozzi, Albino, & Vicari, 2005; de Haan, Bauer, Georgieff, & Nelson, 2000; Luoma, Herrgảrd, & Martikainen, 1998). In Caravale et al. (2005), low-risk preterms, at 3 to 4 years of age, obtained relatively lower scores in an intelligence test, a visual perception test, a location memory test, and a sustained attention test.
1.4 Age Matching
Research in preterm structure or function must consider age matching. Infants can be matched for either maturational age or experiential age (Matthews, Ellis, & Nelson, 1996). Maturational age comparisons use infants who were conceived at the same time and so are of the same postmenstrual age; experiential age comparisons use infants who are all tested the same amount of time after birth and thus have the same chronological or postnatal age. Age correction is controversial (Brandt & Sticker, 1991; DiPietro & Allen, 1991; Ross & Lawson, 1997) because of concerns about mistakenly overcorrecting or mis-estimating when conception actually occurred. Matching preterm and term infants on the basis of postmenstrual age controls for biological maturity; therefore, all infants are developmentally equivalent. This type of matching is based on the argument that development of preterm infants proceeds at the same rate as their term peers with a lag equal to the degree of prematurity. Preterm infants’ age is routinely adjusted in this way when estimating expected age of achievement of developmental milestones. Preterm infants are expected to arrive at milestones at an equivalent postmenstrual (but not postnatal) age to term infants. An advantage of this basis of matching is that biological maturity is controlled. Postmenstrual age matching has been used to examine differences between preterm and term infant brain development (Boardman et al., 2007; Woodward et al., 2004), neuromotor status (Gorga, Stern, Ross & Nagler, 1988), information processing (Rose, Feldman & Jankowski, 2002), language acquisition (Foster-Cohen et al., 2007; Sansavini et al., 2006), school behaviors (for example, aggression and shyness; Nadeau, Tessier, Boivin, Lefebvre & Robaey, 2003), and temperament (Oberklaid, Sewell, Sanson & Prior, 1991; Sajaniemi, Salokorpi & Wendt, 1998). However, this type of matching has often masked developmental problems in preterm infants (Brachfeld, Goldberg, & Sloman, 1980).
To ensure equivalent biological maturity, preterm and term infants necessarily differ on postnatal experience. Matching preterm and term infants on the basis of postnatal age equates groups for postnatal experience. This type of matching has tended to be used in older children. For example, Marlow et al., (2005) investigated cognitive and motor impairments in 6-year-olds, and Carmody et al. (2006) investigated the impact of medical and environmental risk in infancy on 15- to 16-year-olds; both used this standard of matching. Although postnatal age matching allows comparisons of infants with equivalent postnatal experience, it fails to account for additional experience (for example, through antenatal classes) or preparations parents of term infants have taken due to longer pregnancies. Another limitation of postnatal age matching is that preterm infants are developmentally younger than their term peers at any given assessment; in consequence, results may represent effects of immaturity rather than prematurity (Brachfeld et al., 1980). Whether postnatal experiences have extra effects appears to depend on the domain being studied (Goldberg & DiVitto, 1983). Comparisons in which preterm infants have more postnatal experience than term infants provide preterm infants with some apparent advantages.
Brachfeld et al. (1980) suggested using both postnatal and postconceptional age mates as comparisons or controls. Piper, Byrne, Darrah, and Watt (1989), who followed this recommendation, compared motor development of a group of moderately preterm infants to very preterm infants in one group at 8 and 12 months postnatal age and another group at 8 and 12 months postterm age, rather than have a term control group. The use of both postnatal and postterm age allowed Piper et al. (1989) to demonstrate the differential impact of biological maturity on gross and fine motor development. Gross motor function was determined to develop based on biological age; therefore, neurologically intact infants developed at normal rates based on postterm age regardless of gestational age. However, fine motor development was not programmed solely by biological maturity.
Most research in prematurity favors some form of age correction to help determine whether the aspect of development in question is under maturational control or is susceptible to extrauterine experience. For example, Siegel (1983) conducted a longitudinal study in which preterm and term infants were repeatedly assessed over the first 5 years of life. Examining correlations between measures of infants’ corrected and uncorrected ages and later cognitive status, she found that age correction was appropriate in the early months but not later, suggesting that environmental influences grew in importance. Siegel’s results are consistent with later recommendations for either full or half correction for prematurity during the first 2 years of life, but no correction thereafter (Blasco, 1989; Brandt & Sticker, 1991).
2. Infant Visual Habituation and Dishabituation
Given demographic trends in preterm incidence and viability, and confirmation of risk status for developmental outcomes of preterm birth, issues of early assessment have grown in importance. The most prominent contemporary experimental technique for testing perceptual and cognitive competencies in infancy is habituation-dishabituation (Bornstein, 1985, 1998; Colombo & Mitchell, 2009; Kavšek, 2000; Pahnke, 2007). In this paradigm, a habituation stimulus is presented to the infant for either one long period or several short periods (often equal to durations of infants’ individual looks); afterwards, that is in the posthabituation or dishabituation period, a novel stimulus is shown. It is expected that the infant’s attention to the habituation stimulus will decline during the habituation phase, but will afterward increase to the novel stimulus. According to the prevailing comparator model, these two patterns of responding are assumed to reflect information processing. During the habituation phase, the infant’s attention to the habituation stimulus wanes as the infant constructs a mental representation of the stimulus and the stimulus becomes less novel or interesting. If the infant’s attention is reactivated by the novel stimulus, that is if the infant recovers attention, the inference is made that the infant compared the novel stimulus with the mental representation (memory) of the habituation stimulus, and so remembered the one and discriminated the other. Instead of presenting the habituation and the novel stimuli singly and subsequently, the two stimuli can be shown side by side during the dishabituation period. If the infant prefers to look at the novel stimulus, that is if the infant displays a novelty preference, the inference is made that the infant recognizes the habituation stimulus and detects a difference between the stimuli. This performance also indicates the infant’s recognition memory of the habituation stimulus.
The comparator model, and the ideas that habituation must involve the construction of a mental representation or memory trace of the habituation stimulus and dishabituation the successful discrimination between this memory trace and a novel stimulus, goes back to Sokolov’s (1963, 1966) work on the orienting reaction. Several studies have elaborated this cognitive interpretation of habituation-dishabituation (e.g., Hunter & Ames, 1988; Jeffrey, 1976; Kaplan & Werner, 1986; Schöner & Thelen, 2006; Sirois & Mareschal, 2004). For example, Hunter and Ames (1988) postulated a ∩-function between attention and time. More specifically, they argued that an infant’s attention toward a stimulus at first increases, as information about the stimulus is processed, and then decreases, as stimulus processing is progressively completed. If a second stimulus is introduced during the late periods of this habituation process (i.e., when attention toward the first stimulus has largely abated), the novel stimulus, because of its higher attractiveness value, will be preferred. In this case, dishabituation or a novelty preference is observed. If, however, the novel stimulus is shown in the early stages of the habituation process (i.e., when interest in the habituation stimulus has started to increase), the infant will prefer to look at the habituation stimulus because its attention-eliciting value is higher than is that of the newly introduced stimulus. In other words, the infant displays a familiarity preference.
Looking appears to have a natural course of development across infancy. Several studies have demonstrated an increase in duration of spontaneous looking at visual targets from birth to 2 or 3 months of age (see Colombo et al., 1999; Ruff & Rothbart, 1996). This phenomenon may originate from the emergence of alertness: over the first 2 to 3 months, the amount of time spent in a quiet awake state dramatically increases (e.g., Berg & Berg, 1987; Colombo, 2001). The increase of look duration during the first months of life is followed by a steep decrease of looking to about 6 to 9 months of age.
According to the comparator model, the age-related decrease in look duration reflects an increase in speed of stimulus encoding and/or of processing efficiency (e.g., Bornstein, 1998; Rose & Tamis-LeMonda, 1999). An alternative interpretation, disengagement theory (Colombo, 1995, 2002), suggests that, rather than reflecting infants’ increasing capability of stimulus encoding, duration of looking at a stimulus display reflects infants’ increasing ability to disengage from a stimulus. Recent research suggests that both stimulus encoding and disengagement contribute to the overall age-related decrement in duration of looking observed during the first year of life (Colombo, Richman, Shaddy, Greenhoot, & Maikranz, 2001; Colombo, Shaddy, Richman, Maikranz, & Blaga, 2004; Domsch, Lohaus, & Thomas, 2008; for a discussion, see Kavšek, in preparation).
Ruff and Rothbart (1996; Rothbart & Bates, 2006) hypothesized that infant attention during the middle part of the first year of life is controlled by the posterior, reactive attentional brain system. This system guides object exploration: Attention is sustained if the object retains some novelty. With increasing familiarity, attention wanes, that is habituation occurs. Preterms habituate less efficiently than conceptionally matched term infants when they suffer CNS-related complications associated with prematurity, such as IVH (Ross, Tesman, Auld, & Nass, 1992), suggesting that visual functioning among preterm and term infants may differ (Bonin, Pomerleau, & Malcuit, 1998). Using a “continuous familiarization” task, which measures the speed of information processing by presenting infants with a series of paired stimuli where one changes from trial-to-trial and the other remains the same throughout, Rose et al. (2002) found that preterm and term infants did not differ on number of infants reaching criterion at each age, but that term infants were significantly faster at processing the stimuli than preterm infants at 5, 7, and 12 months. Term infants took about 20% fewer trials to reach criterion and spent 24–33% less time looking to the familiar stimulus than preterm infants. Although preterm infants were as quick to orient to change in the environment, they were slower at encoding what they saw. Preterm infants appear to be perceptually capable but cognitively disadvantaged. This finding in the visual modality has been replicated in auditory and tactile perception; preterm infants have been shown to respond to auditory and tactile stimuli in a similar manner to term controls but to be slower at processing information about these stimuli (see Goldberg & DiVitto, 1983). Thus, the information-processing disadvantage in preterm, relative to term, infants is generalized.
Measurement studies of the procedural and psychometric characteristics of habituation and of dishabituation in term infants show robust individual variation and adequate short-term reliability. These are two basic psychometric criteria. First, habituation and dishabituation are characterized by adequate individual variation. From a qualitative view, some infants show a linear or exponential decrease in habituation (to a learning criterion); other infants first increase then decrease looking; and still other infants show a fluctuating looking pattern (Bornstein & Benasich, 1986; Colombo et al., 2004). This qualitative perspective on habituation is supported by quantitative measures of duration and magnitude. For example, infants who habituate in a linear or exponential fashion require about one half the accumulated looking time to reach a constant habituation criterion as increase-decrease and fluctuating infants, who require approximately equivalent amounts of time (Bornstein & Benasich, 1986). Similarly, infants show substantial individual variation in dishabituation (Arterberry & Bornstein, 2002).
Second, the reliability of the habituation-dishabituation paradigm has been investigated qualitatively and quantitatively as well. Qualitatively, a nominal scale metric shows significant 10-day test-retest repeatability of habituation pattern (Bornstein & Benasich, 1986). More typical are reports of the reliability of quantitative habituation data. Tests administered closer in time yield higher reliability estimates: Day-to-day reliability (r) reaches .60 (e.g., Colombo, 1993). Kavšek (2004a) pointed out that mean short-term reliability of total amount of looking in habituation is .40. Mean short-term reliability of novelty preference is .27. Of course, estimates of the reliability of both habituation and dishabituation can be expected to vary with state and age of the child, stimulus used, and so forth.
The validity of the habituation-dishabituation paradigm as a measure of cognition is supported by evidence from studies of concurrent and predictive validity. Successful habituation minimally implies neurologic integrity and sensory competence in the infant. Beyond that, habituation represents an elementary kind of nonassociative learning (Kandel, 2007; Thompson & Spencer, 1966). The cognitive information-processing interpretation of habituation-dishabituation under the comparator model makes several straightforward predictions.
First, on an information-processing interpretation older and more mature babies ought to habituate more efficiently than younger and less mature babies (see Fantz, 1964). Bornstein, Pêcheux, and Lécuyer (1988) recorded total accumulated looking times over weekly habituation sessions in the same infants between 2 and 7 months of age. As they aged across the first year, infants required less and less cumulative exposure to reach a constant habituation criterion. The finding of significant decreases in duration of looking in infants across the initial parts of the first year has been repeated many times (Colombo & Mitchell, 2009; Colombo et al., 2004; Courage, Reynolds, & Richards, 2006; Friedman & Carpenter, 1971; Shaddy & Colombo, 2004; Slater & Morison, 1991).
The second prediction of an information-processing interpretation is related to the first: Normally developing babies habituate and dishabituate more efficiently than babies born at-risk for cognitive developmental delay. Children with Down syndrome or brain damage (e.g., micro- or anencephalia) either fail to habituate and dishabituate or habituate and dishabituate relatively inefficiently (Hepper & Shahidullah, 1992; Lester, 1975), as do infants who have been exposed in utero to cocaine or alcohol (S. W. Jacobson, J. L. Jacobson, Sokol, Martier, & Ager, 1993; S. W., Jacobson, J. L. Jacobson, Sokol, Martier, & Chiodo, 1996; Mayes, Granger, Frank, Schottenfeld, & Bornstein, 1993). As we see later, preterm infants (e.g., Rose et al., 2002) habituate and dishabituate less efficiently than term infants.
The third information-processing prediction is that infants ought to habituate to “simpler” stimuli more efficiently than to more “complex” stimuli. Evidence for this finding is replete in the literature on perceptual development (e.g., Caron & Caron, 1969; Hunter, Ames, & Koopman, 1983).
Fourth, if habituation involves processing information, infants habituated to one stimulus should later be able to distinguish a novel stimulus in comparison with their internal mental representation of the now familiar stimulus. Several studies show significant associations between infants’ habituation and dishabituation performance (e.g., Bornstein & Ruddy, 1984; Colombo, Mitchell, & Horowitz, 1988). Slater, Morison, and Rose (1983) habituated newborns to a stimulus, allowing them to use only one eye. On later testing, when the babies viewed the two stimuli through the other eye they recovered looking to a new stimulus, compared to the habituation stimulus. This interocular transfer indicates that information about the stimulus acquired via habituation must be processed centrally (cortically or subcortically) in the brain.
Evidence supporting each of the four foregoing predictions contributes to validating an information-processing interpretation of visual habituation-dishabituation in infants. The information-processing interpretation converges with concurrent individual differences in the normal population. Infants and young children who habituate efficiently prefer complex over simple patterns, show advanced sensorimotor development, explore their environment rapidly, play in relatively more sophisticated ways, solve problems quickly and attain concepts readily, and excel at operant learning, oddity identification, picture matching, and block configuration (for reviews, see Bornstein, 1985; Colombo, 1993).
3. Predictive Validity of Visual Habituation and Dishabituation in Preterm and Term Infants
The validity of infant habituation-dishabituation has also been evaluated by comparing infant performance early in life with performance years later as children. The presumption in this comparison is that, if individuals who perform well on infant tests also do well on standardized tests (such as of intelligence) as children, then the original tests must be assessments of cognition in infancy. Habituation possesses moderate lagged predictive validity. Infants who habituate efficiently in the first 6 months of life later, between 2 and at least 18 years of age, perform better on assessments of cognitive competence, including standardized psychometric tests of intelligence as well as measures of representational ability, such as language and symbolic play. Sigman, Cohen, and Beckwith (1997) found that newborns’ length of fixation predicted adolescents’ span of apprehension at 18 years, a speed-of-processing task in which adolescents had to say whether or not a target was present in a tachistoscopically presented array. Rose and Feldman (1995) examined relations between infant visual recognition memory and child performance at 11 years in a Specific Cognitive Abilities test (SCA: Cyphers, Fulker, Plomin, & DeFries, 1989; Thompson, Detterman, & Plomin, 1991). They found that nearly all their infancy measures related to the assessment of perceptual speed.
Several meta-analyses conclude that there is a moderate, but significant, correlation between infant visual habituation-dishabituation and standardized test outcomes later in childhood (e.g., Bornstein & Sigman, 1987; Colombo, 1993; Kavšek, 2004b; McCall & Carriger, 1993). Most recently, Kavšek (2004b) included 38 samples from 25 studies. The averaged weighted normalized predictive correlation coefficient (Hedges & Olkin, 1985) across studies of habituation in populations of normal babies is .40; for at-risk samples, it is .30; and for all samples combined, .36. These predictive correlations are not due to extreme scores or atypical populations or random effects, but hold for populations of both normal and at-risk infants across years, samples, ages, laboratories, stimuli, and modalities (including visual and auditory) as well as with different procedures and measures in infancy and childhood. Furthermore, Kavšek (2004b) identified an interaction between predictor and risk status of infant participants. More specifically, for non-clinical samples, the correlation between habituation and later intelligence was higher than was the correlation between dishabituation and later intelligence, rs = .40 and .32 respectively. For risk samples, however, dishabituation turned out to be a more robust predictor of later cognition and intelligence than habituation, rs = .50 and .30, respectively.
Although we do not know whether (or how many) studies failed to obtain predictive validity on these infant measures, we know of no correlations that report findings in the opposite direction. Moreover, the predictive validity of cognitive performance between infancy and childhood might depend, in part or in whole, on stability in the infant’s social, didactic, or material environments - how significant people in children’s lives interact with them, how they teach, or what kinds of physical surroundings they provide. Experimental observation shows, however, that, although mother contributes to infant cognitive growth, some stability obtains in the infant independent of maternal early and late didactic contributions (Bornstein, 1985; Bornstein et al., 2006). External experiences and family influences, both genetic and experiential, undoubtedly play a role in child mental development, but they do not exclusively mediate predictive validity (e.g., Gottfried, 1984; Scarr, Weinberg, & Waldman, 1993). A margin of validity in mental development appears to obtain in the child independent of environmental contributions. Moreover, other noncognitive mediators of validity might arise within the child, rather than from the child’s experience. Succeeding in infancy at habituation and in childhood on mental assessments presumably requires possessing motor skills as well as a persistent or vigilant temperament style. However, habituation in infancy is predictive of later cognitive function over and above infant temperament and spontaneous infant motor activity (Bornstein & Colombo, 2010; Bornstein et al., 2006).
In a research program with VLBW preterm and term infant (for sample characteristics, see Rose et al., 2001, 2002), Rose, Feldman, Jankowski, and van Rossem (2005 Rose, Feldman, Jankowski, and van Rossem (2008) found lower performance in preterms’ childhood cognitive scores. Furthermore, preterms’ childhood cognitive outcome was mediated by disadvantages in information processing during infancy. For example, 12-month-old preterms scored lower than 12-month-old terms on two common attention variables (i.e., look duration and shift rate) and encoding speed (see also Rose et al., 2001, 2002). In a “cognitive cascade,” these variables influenced visual recognition memory and representational competence, which, in turn, influenced mental status at 2 and 3 years of age (Rose et al., 2008).
By including both preterms and terms in a common experimental design, this research program directly compares the developmental trajectories of the two groups. This research provides evidence for striking differences in habituation and dishabituation performance between preterm and term infants. Moreover, the study suggests that preterms’ relative disadvantage in later cognitive development might be traced back to early attention differences. The existence of a substantial relation between early visual performance and later cognitive outcome in preterms has been confirmed in multiple investigations (e.g., Cohen & Parmelee, 1983; Ortiz-Mantilla, Choudhury, Leevers, & Benasich, 2008; Rose & Wallace, 1985a, 1985b; Sigman et al., 1997; Sigman, Cohen, Beckwith, Asarnow, & Parmelee, 1991).
4. Visual Habituation and Dishabituation in Preterm versus Term Infants
Overall, empirical findings point to a difference in visual habituation-dishabituation performance between preterm and term infants. Under the comparator model, longer looking during habituation and weaker dishabituation responses in preterms imply disadvantages in stimulus encoding and stimulus discrimination capabilities. We now explore these differences. Furthermore, we analyze the roles of additional risk-factors, including age and experimental conditions (i.e., the experimental procedure and the kind of stimuli). Van de Weijer-Bergsma et al. (2008) reported that attention development in preterms is inferior to that in terms. These authors primarily concentrated on infants’ ability to orient, maintain attention, and shift between objects and events, but not on visual habituation and dishabituation. By focusing on visual habituation-dishabituation, the present review complements van de Weijer-Bergsma et al. (2008).
4.1 Sampling
Tables 1–4 list studies that empirically compared visual habituation-dishabituation performance of preterm and term infants. These studies are included in the present review. The studies are further subdivided into investigations of preterm samples without additional risk factors (Tables 1 and 2) and investigations of preterm samples with additional risks (Tables 3 and 4). Risk factors are listed in Table 4. They include IVH, RDS (e.g., Landry, Leslie, Fletcher, & Francis, 1985; Rose, Feldman, McCarton, & Wolfson, 1988), hyaline membrane disease (Cohen, 1981), and cardiac anomalies (Millar, Weir, & Supramian, 1991). In two studies, the nature of additional risk factors was not specified (Caron & Caron, 1981; Holmes, Reich, & Gyurke, 1989), making it difficult to draw firm conclusions about the samples. For preterm samples without additional risks, 12 publications with 27 comparisons are included; for preterm samples with additional risks, 12 publications with 41 comparisons are included. The studies selected were found using a computerized search of PSYCLIT supplemented by exhaustive examination of relevant literatures. For each empirical comparison, Tables 1 and 3 contain information about (corrected) age at time of testing, stimuli, habituation and dishabituation measures, and habituation and dishabituation performance of the preterm and term participants. In addition, the tables document whether a significant difference between preterms’ and terms’ habituation and dishabituation results was found. The tables also contain one-tailed probabilities p and effect sizes d for significant group differences (p ≤ .05). Probabilities and effect sizes refer to t tests comparing means. Probabilities were one-tailed because all significant group differences indicated that, as expected, preterms had lower scores than terms. Unfortunately, not all publications provided sufficient information to compute t statistics. Effect sizes were estimated according to Cohen (1977; Buchner, Erdfelder, & Faul, 1997). Cohen’s effect size conventions were used: d = 0.20 as “small”; d = 0.50 as “medium”; and d = 0.80 as “large.” Tables 2 and 4 complement Tables 1 and 3 by listing samples size, gestational age, postmenstrual age at time of testing, birth weight, and additional characteristics of the preterm samples.
Table 1.
Authors | Infant Age at Time of Testing1M (SD) | Stimuli | Habituation Measure | Dishabituation Measure | Difference in Stimulus Encoding?2 p3/d4 |
Difference in Stimulus Discrimination?2 p3/d4 |
Habituation in Preterms?5 | Dishabituation in preterms?5 | Habituation in Terms?5 | Dishabituation in Terms?5 |
---|---|---|---|---|---|---|---|---|---|---|
Bonin, Pomerleau, & Malcuit (1998) measurement 1 |
2.0 | naturalistic faces naturalistic children’s faces, abstract patterns |
infant-controlled FFD6 |
recovery of attention novelty preference |
— —7 |
— —7 |
+8 +9 |
+ + |
+8 +9 |
+ + |
measurement 2 | 3.92 | naturalistic faces naturalistic children’s faces, abstract patterns |
infant-controlled FFD |
recovery of attention novelty preference |
— —7 |
— —7 |
+8 +9 |
+ + |
+8 +9 |
+ + |
measurement 3 | 5.94 | naturalistic faces naturalistic children’s faces, abstract patterns |
infant-controlled FFD |
recovery of attention novelty preference |
— —7 |
— —7 |
+8 +9 |
+ + |
+8 +9 |
+ + |
Fagan, Fantz, & Miranda (1971, quoted from Fantz, Fagan, & Miranda (1975) | 1.15–2.08 2.54–4.1611 |
abstract patterns abstract patterns |
FFD or FPD10 FFD or FPD |
novelty preference novelty preference |
not given —7 |
not given — |
?12 +9 |
?12 + |
?12 +9 |
?12 + |
Field, Woodson, D. Cohen, Greenberg, Garcia, & Collins (1983) | neonatal period (no age correction) | naturalistic facial emotional expressions | infant-controlled | recovery of attention | +20 | +20 | + | + | + | + |
Friedman, Jacobs, & Werthmann (1981) | neonatal period | green vs. red real box | infant-controlled | not tested | + .01/0.84 |
not tested | +8 | not tested | +8 | not tested |
Kopp, Sigman, Parmelee, & Jeffrey (1975) | neonatal period | checkerboard patterns | FPD | not tested | + .04/0.5121 |
not tested | not given | not tested | not given | not tested |
Mash, Quinn, Dobson, & Narter (1998) study 1 |
preterms: 3.58 terms: 3.14 |
dot patterns (to “above” vs. “below” categories) |
FPD | novelty preference | — | — | —13 | + | —13 | + |
study 214 | preterms: 3.58 terms: 3.72 |
naturalistic pictures of cats and dogs (categorization task) | FPD | novelty preference | — | + .002/1.08 |
— | — | — | + |
Rose (1980) study 1 |
preterms: 6.34 terms: 6.31 |
abstract patterns abstract patterns naturalistic faces |
FFD FFD FFD |
novelty preference | ?16 —7 ?16 |
?16 — ?16 |
?17 ?17 ?17 |
?17 ?17 ?17 |
+9 ?17 +9 |
+ ?17 + |
study 215 | preterms: 6.34 terms: 6.31 |
abstract patterns abstract patterns naturalistic faces |
FFD FFD FFD |
novelty preference | —7 —7 —7 |
— — — |
+9 ?17 +9 |
+ ?17 + |
+9 ?17 +9 |
+ ?17 + |
Rose (1983) study 1 |
preterms: 6.67 terms: 6.4 |
abstract real 3D patterns | FFD | novelty preference | —18 | +18 .01/0.77 |
+9 | + | +9 | + |
study 2 | preterms: 13.0 terms: 12.8 |
abstract real 3D patterns | FFD | novelty preference | —18 | —18 | +9 | + | +9 | + |
Rose, Gottfried, & Bridger (1978) study 1 |
preterms: 12.56 terms: 12.33 |
abstract patterns | FFD | novelty preference | —7 | — | +9 | + | +9 | + |
study 214 | preterms: 12.56 terms: 12.47 |
abstract patterns | FFD | novelty preference | —7 | — | +9 | + | +9 | + |
Rose, Gottfried, & Bridger (1979) study 1 |
preterms: 6.6 terms: 6.88 |
abstract patterns | FFD | novelty preference | ?16 | ?16 .08/0.48 |
?17 | ?17 | +9 | + |
study 2 | preterms: 12.33 terms: 12.49 |
abstract patterns | FFD | novelty preference | —7 | — | +9 | + | +9 | + |
Sigman, Kopp, Littman, & Parmelee (1977) | neonatal period | checkerboard patterns | FPD | not tested | +22 | not tested | not given | not tested | not given | not tested |
Sigman & Parmelee (1974) | preterms19: 4.16 terms: 4.39 |
checkerboard pattern vs. abstract patterns | FPD | novelty preference | — | +23 | + | — | + | + |
Notes. Standard deviations are given in parentheses.
Age at time of testing in months. For the preterm infants, age is corrected (= age from expected date of birth). Age of both preterms and terms is given if age at time of testing was different.
+: A significant difference between preterms and terms to the disadvantage of the preterms was observed. —: No significant difference between preterms and terms was observed.
One-tailed probability for value of t comparing group means.
Effect size according to Cohen (1977).
+ A significant habituation/dishabituation was observed. —: No significant habituation/dishabituation was observed.
FFD: Fixed fixation duration.
: Deduced from there being no group difference in dishabituation performance.
: An infant-controlled habituation procedure was used. Hence, the infants are considered as having habituated.
Deduced from there being a significant dishabituation. Hence, the infants must have successfully habituated.
FPD: Fixed presentation duration.
The participants were tested every two weeks. The whole testing period was subdivided into two phases; results obtained in each phase were comparable.
Habituation might have interfered with dishabituation: There was no significant dishabituation; whether the infants had habituated was not tested. Hence, it is possible that the infants continued to habituate (i.e., to look at the familiar stimulus) during the dishabituation phase, thereby suppressing a clear dishabituation reaction.
Despite there being no significant decrease in fixation during the habituation period, the infants displayed a significant dishabituation.
The same preterms, but different groups of terms were investigated in studies 1 and 2.
The same terms, but different groups of preterms were investigated in studies 1 and 2.
Term infants displayed a significant dishabituation reaction. In the preterm infants, however, no significant dishabituation response was observed. Due to using a fixed fixation duration habituation procedure, it remains unclear whether the preterms continued to look at the habituation stimulus during the dishabituation period, that is, to encode the habituation stimulus, thereby producing a null result. If so, the dishabituation response in the preterms might be confounded with continuation of habituation, and it remains unclear whether or not the preterms’ ability to display a novelty response is inferior to that of the terms. Furthermore, the non-significant dishabituation in combination with a fixed fixation duration habituation procedure leaves open whether the preterm infants had habituated. Hence, it cannot be determined whether or not their habituation performance was comparable to that of the terms.
There was no significant dishabituation response. Due to using a fixed fixation duration habituation procedure, it remains unclear whether the infants continued to look at the habituation stimulus during the dishabituation period, that is, to encode the habituation stimulus, thereby producing a null result. If so, the dishabituation reaction in the infants might be confounded with continuation of habituation and it is unclear whether or not the infants were able to discriminate between the posthabituation stimuli. Furthermore, the non-significant dishabituation in combination with a fixed fixation duration habituation procedure leaves open whether the infants had habituated.
See the main text for a comment.
The preterms failed to habituate and to dishabituate.
Group differences were assessed by a common measure, F(2,92) = 5.41, p = .006.
Values for total fixation. Values for first fixation are p = .02, d = 0.62.
F(1,38) = 5.45, p = .025.
Values for the groups × stimulus novelty interaction are F(1,36) = 14.33, p < .01.
Table 3.
Authors | Infant Age at Time of Testing1M (SD) | Stimuli | Habituation Measure | Dishabituation Measure | Difference in Stimulus Encoding?2 p3/d4 |
Difference in Stimulus Discrimination?2 p3/d4 |
Habituation in Preterms?5 | Dishabituation in Preterms?5 | Habituation in Terms?5 | Dishabituation in Terms?5 |
---|---|---|---|---|---|---|---|---|---|---|
Caron & Caron (1981; see also Caron, Caron, & Glass, 1983) measurement 1 |
2.77 | line drawings of faces vs. non-faces with relational change | infant-controlled | novelty preference | — — |
+ (configural discrimination/conf) p < .01 — (component discrimination/comp) |
+8 +8 |
— (conf) + (comp) |
+8 +8 |
+ (conf) — (comp) |
measurement 2 | 4.16 | above vs. below relational change | infant-controlled | novelty preference | — — |
+ (conf) p < .05 — (comp) |
+8 +8 |
— (conf) + (comp) |
+8 +8 |
+ (conf) — (comp) |
measurement 3 | 4.85 | line drawings of faces with relational change | infant-controlled | novelty preference | — — |
+ (conf) p < .05 — (comp) |
+8 +8 |
— (conf) + (comp) |
+8 +8 |
+ (conf) + (comp) |
measurement 4 | 5.54 | naturalistic faces: neutral vs. smile | infant-controlled | novelty preference | — — |
— (conf) — (comp) |
+8 +8 |
— (conf) + (comp) |
+8 +8 |
+ (conf) — (comp) |
Cohen (1981) measurement 1/study 1 |
4.62 | naturalistic faces | infant-controlled | recovery of attention | — | — | +8 | — | +8 | — |
measurement 1/study 214 | 4.62 | naturalistic faces | infant-controlled | recovery of attention | + | + | +8 | + | +8 | — |
measurement 2 | 7.62 | naturalistic faces | infant-controlled | recovery of attention | — | — | +8 | + | +8 | + |
measurement 3 | 11.32 | naturalistic faces | infant-controlled | recovery of attention | — | — | +8 | + | +8 | + |
Holmes, Nagy Reich, Gyurke (1989) measurement 1 |
2 | outline drawings of faces | FPD | novelty preference | — | not given | ?12 | ?12 | ?12 | ?12 |
measurement 2 | 4 | outline drawings of faces | FPD | novelty preference | — | ?20 | ?12 | ?12 | +9 | + |
measurement 3 | 6 | outline drawings of faces | FPD | novelty preference | — | ?20 | ?12 | ?12 | +9 | + |
Landry, Leslie, Fletcher, & Francis (1985) study 1 |
7 | abstract patterns | 7 trials; length of each trial was infant-controlled | recovery of attention | — | — .055/0.64 |
+ | + | + | + |
study 215 | 7 | abstract patterns | 7 trials; length of each trial was infant-controlled | recovery of attention | — | — | + | + | + | + |
Lewis (1981)21 study 1 |
3–6 | abstract patterns vs. a naturalistic picture of a family | FPD | recovery of attention | — | not tested | — | — | — | not tested |
study 2 | 9–12 | see study 1 | FPD | recovery of attention | + | not tested | — | — | + | not tested |
study 3 | 18–24 | see study 1 | FPD | recovery of attention | — | not tested | + | + | + | not tested |
Millar, Weir, & Supramiam (1991) study 1 |
preterms: 7.70 terms: 7.30 |
abstract patterns | FPD | recovery of attention | +25 | +23 | — | — | + | + |
study 215 | preterms: 8.09 terms: 7.30 |
abstract patterns | FPD | recovery of attention | +25 | +23 | — | — | + | + |
study 3 | preterms: 6.86 terms: 7.70 |
naturalistic faces | FPD | recovery of attention | —26 | — | + | + | + | + |
study 422 | preterms: 6.79 terms: 7.70 |
naturalistic faces | FPD | recovery of attention | —27 | — | + | + | + | + |
Ortiz-Mantilla, Choudhoury, Leevers, & Benasich (2008) measurement 1 |
preterms: 6.7 terms: 6.6 |
naturalistic faces | infant-controlled | novelty preference | — | — | + | + | + | + |
measurement 2 | preterms: 9.7 terms: 9.6 |
naturalistic faces | infant-controlled | novelty preference | +24 .005/0.82 |
— | + | + | + | + |
Rose, Feldman, & Jankowski (2001) measurement 1 |
preterms: 5.22 terms: 5.27 |
naturalistic faces abstract patterns |
FFD | novelty preference | + .04/0.29 — |
+ .02/0.30 — |
+9 +9 |
+ + |
+9 +9 |
+ + |
measurement 2 | preterms: 7.94 terms: 7.78 |
naturalistic faces abstract patterns |
FFD | novelty preference | + < .001/0.55 + .002/0.42 |
+ .01/0.37 + .04/0.26 |
+9 +9 |
+ + |
+9 +9 |
+ + |
measurement 3 | preterms: 13.30 terms: 13.12 |
naturalistic faces abstract patterns |
FFD | novelty preference | — — |
— + .006/0.41 |
+9 +9 |
+ + |
+9 +9 |
+ + |
Rose, Feldman, & Jankowski (2002) measurement 1 |
preterms: 5.22 terms: 5.26 |
naturalistic faces of infants | continuous familiarization | not tested | + .004/0.47 |
not tested | + | + | + | + |
measurement 2 | preterms: 7.16 terms: 7.09 |
continuous familiarization | not tested | + .003/0.46 |
not tested | + | + | + | + | |
measurement 3 | preterms: 12.38 terms: 12.84 |
continuous familiarization | not tested | + .013/0.34 |
not tested | + | + | + | + | |
Rose, Feldman, McCarton, & Wolfson (1988) | 7 | abstract patterns naturalistic faces geometric 3D forms |
FFD | novelty preference | + .01/0.49 — — |
?16 .001/0.72 ?16 .06/0.36 — |
?17 ?17 ?17 |
?17 ?17 ?17 |
+9 +9 ?17 |
+ + ?17 |
Ross, Tesman, Auld, & Nass (1992) study 1 |
10 (no age correction) | outline drawing of a face vs. scrambled face | infant-controlled | novelty preference | + .01/0.61 |
— | +8 | + | +8 | + |
study 215 | 10 (no age correction) | outline drawing of a face vs. scrambled face | infant-controlled | novelty preference | — | — | +8 | + | +8 | + |
Spungen, Kurtzberg, & Vaugham (1985) | neonatal period | abstract patterns | infant-controlled | recovery of attention | + .<.001/1.03 |
— | +8 | — | +8 | + |
Notes. Standard deviations are given in parentheses.
Age at time of testing in months. For the preterm infants, age is corrected (= age from expected date of birth). Age of both preterms and terms is given if age at time of testing was different.
+: A significant difference between preterms and terms to the disadvantage of the preterms was observed. —: No significant difference between preterms and terms was observed.
One-tailed probability for value of t comparing group means.
Effect size according to Cohen (1977).
+ A significant habituation/dishabituation was observed. —: No significant habituation/dishabituation was observed.
FFD: Fixed fixation duration.
: Deduced from there being no group difference in dishabituation performance.
: An infant-controlled habituation procedure was used. Hence, the infants are considered as having habituated.
Deduced from there being a significant dishabituation. Hence, the infants must have successfully habituated.
FPD: Fixed presentation duration.
The participants were tested every two weeks. The whole testing period was subdivided into two phases; results obtained in each phase were comparable.
Habituation might have interfered with dishabituation: There was no significant dishabituation; whether the infants had habituated was not tested. Hence, it is possible that the infants continued to habituate (i.e., to look at the familiar stimulus) during the dishabituation phase, thereby suppressing a clear dishabituation reaction.
Despite there being no significant decrease in fixation during the habituation period, the infants displayed a significant dishabituation.
The same preterms, but different groups of terms were investigated in studies 1 and 2.
The same terms, but different groups of preterms were investigated in studies 1 and 2.
Term infants displayed a significant dishabituation reaction. In the preterm infants, however, no significant dishabituation response was observed. Due to using a fixed fixation duration habituation procedure, it remains unclear whether the preterms continued to look at the habituation stimulus during the dishabituation period, that is, to encode the habituation stimulus, thereby producing a null result. If so, the dishabituation response in the preterms might be confounded with continuation of habituation, and it remains unclear whether or not the preterms’ ability to display a novelty response is inferior to that of the terms. Furthermore, the non-significant dishabituation in combination with a fixed fixation duration habituation procedure leaves open whether the preterm infants had habituated. Hence, it cannot be determined whether or not their habituation performance was comparable to that of the terms.
There was no significant dishabituation response. Due to using a fixed fixation duration habituation procedure, it remains unclear whether the infants continued to look at the habituation stimulus during the dishabituation period, that is, to encode the habituation stimulus, thereby producing a null result. If so, the dishabituation reaction in the infants might be confounded with continuation of habituation and it is unclear whether or not the infants were able to discriminate between the posthabituation stimuli. Furthermore, the non-significant dishabituation in combination with a fixed fixation duration habituation procedure leaves open whether the infants had habituated.
See the main text for a comment.
The preterms failed to habituate and to dishabituate.
Term infants displayed a significant dishabituation reaction. In the preterm infants, however, no significant dishabituation response was observed. Due to not testing whether the infants had habituated, it remains unclear whether the preterms continued to look at the habituation stimulus during the dishabituation period, that is, to encode the habituation stimulus, thereby producing a null result. If so, the dishabituation response in the preterms might be confounded with continuation of habituation and it remains unclear whether or not the preterms’ ability to display a novelty response is inferior to that of the terms.
It is not specified whether age had been corrected for prematurity.
The same terms, but different groups of preterms were investigated in studies 3 and 4.
Data from study 1 and 2 were assessed in a common ANOVA, F(1,36) = 3.36, p = .07.
Result is based on trials needed to reach habituation criterion. Difference between preterms and terms in total looking time, however, was not statistically significant, t(44) = 0.61, p = .27, d = 0.18.
Data from study 1 and 2 were assessed in a common ANOVA, F(1,34) = 4.38, p < .05.
Data from study 3 and 4 were assessed in a common ANOVA, F(2,43) = 2.82, p = .07.
4.2 Non-risk Preterm Infants
According to Table 1, only a small number of significant differences between preterms and terms emerged in visual habituation or visual dishabituation variables. Only very few effect sizes and probabilities could be computed. However, computed effect sizes were of medium or even large magnitude. For habituation differences between terms and preterms in habituation, Friedman, Jacobs, and Werthmann (1981) obtained a large effect size of d = 0.84 (p = .01) and Kopp, Sigman, Parmelee, and Jeffrey (1975) found a significant result (p = .04) with a medium effect size of d = 0.51. For group differences in dishabituation performance, effect sizes were large in both study 2 conducted by Mash, Quinn, Dobson, and Narter (1998), d > 0.80 (p = .002), and study 1 conducted by Rose (1983), d = 0.77 (p = .01). A medium effect size was obtained in study 1 conducted by Rose, Gottfried, and Bridger (1979), d = 0.48. Significance in this study, however, was weak, p = .08. Furthermore, in most studies, like their term counterparts, preterms displayed significant habituation and dishabituation.
4.2.1 Habituation
In all studies that tested infants during the neonatal period, meaning that term infants were tested within the first 3 days after birth, habituation performance in non-risk preterms is lower than that in term infants (Field, Woodson, Cohen, Greenberg, Garcia, & Collins, 1983; Friedman et al., 1981, d = 0.84, p = .01; Kopp et al., 1975, d = 0.51, p = .04; Sigman, Kopp, Littman, & Parmelee, 1977). In these studies, stimuli employed were checkerboard patterns of varying complexity (Kopp et al., 1975; Sigman et al., 1977), facial expressions (Field et al., 1983), or colored 3D forms (Friedman et al., 1981). When using facial expressions, Field et al. (1983) additionally established that young preterms were not able to discriminate targets. In the other studies with neonates, dishabituation performance was not assessed.
In the Field et al. (1983) study, for the preterm sample, date of testing was not determined by the infants’ corrected age. Instead, infants were assessed directly after birth. In contrast, in all other studies, preterms were equivalent to their term counterparts in terms of postmenstrual age, meaning that they were tested when having reached their expected date of birth. Hence, not only are preterms’ habituation skills lower than those of terms directly after birth, as shown in Field et al. (1983) for example, but also when they had had the opportunity to accrue extrauterine experience for about 6 to 7 weeks, as shown in the other studies with infants in the neonatal period. From this pattern of findings we conclude that the effect of (pre)maturity is stronger than the effect of postnatal experience, which appears not to compensate for the loss of intrauterine development. Beyond the neonatal period, the initial disadvantage in preterm habituation performance abates rapidly. According to Bonin et al. (1998), at the latest at (corrected) age 2 months, preterms have made up for their encoding disadvantage. Unfortunately, the reasons for this “catch up” are not clear. That is, it is unknown whether maturation or extrauterine experiences are responsible for the recovery of brain structures underlying preterm infants’ habituation performance.
As Table 1 shows, in some studies, abstract two-dimensional patterns, such as curved black lines on a white background and arrangements of identical dots, have served as experimental stimuli (see Table 1). Overall, these studies provide no evidence for differences between preterms and terms. This finding may be due to there being no information-processing disadvantages in the preterm infants. Alternatively, abstract 2D patterns may be unsuited to detect group differences in visual habituation and dishabituation.
In some studies, it can be questioned whether infants were able to detect differences between the experimental displays, whether they were able to encode the habituation stimulus, and whether there was a difference between terms’ and preterms’ habituation-dishabituation (Fagan, Fantz, & Miranda, 1971, quoted from Fantz, Fagan, & Miranda, 1975; Rose, 1980; Rose et al., 1979). In these studies, a familiarization technique was used by either presenting a stimulus for a fixed amount of time prescribed by the experimenter (“fixed presentation duration procedure”) or presenting a stimulus until the infant had inspected it for a predetermined fixed amount of time (“fixed fixation duration procedure”). Studies that have used such fixed procedures usually present familiar and novel test displays simultaneously, that is side by side during the follow-on period. Looking times toward the test displays are compared to establish a novelty preference. A problem with this procedure is the possible continuation of habituation during the dishabituation period, especially when very short fixed duration times are used (e.g., Hunter & Ames, 1988). More specifically, when employing short fixed fixation or presentation durations, the experimenter might end the stimulus exposure period before the infant has habituated. In this case, the infant might continue to habituate during the posthabituation period, that is, the infant might continue to inspect the familiar stimulus. As a consequence, the infant’s attention will be either distributed evenly across the test displays or the infant might display a familiarity preference. For example, in Rose et al. (1979) the exposure period lasted until the infant had accumulated 20 sec of looking at a stimulus. Subsequently, unlike term infants, 6-month-old preterms did not display a preference for a novel test stimulus. Because it cannot be determined whether the preterm infants’ encoding was complete after 20 sec of looking, it remains open whether the null result established in the test phase was due to preterm infants’ inability to discriminate between the test displays. It is possible that preterms could perceive the difference between test displays, but that they also tended to continue habituation. As a result, their looking was distributed equally between the test stimuli. As a further consequence, in such paradigms it cannot be determined whether preterms’ “habituation” and “dishabituation” were comparable to the terms’ “habituation” and “dishabituation”.
4.2.2 Dishabituation
There is evidence that non-risk preterms’ dishabituation capabilities are inferior to those of terms during the first months of life. Sigman and Parmelee (1974) reported that 4-month-old preterms could not distinguish between very distinct displays (a checkerboard pattern vs. abstract 2D patterns). Rose (1983), who used abstract 3D forms, reported that 6-month-old preterms did not discriminate between stimuli. Finally, Mash et al. (1998) established that 3.5-month-old preterms were not able to distinguish between cats and dogs in a habituation categorization task. Effect sizes were large, d = 0.77 for Rose (1983) and d > 0.80 for Mash et al. (1998), indicating that the group differences were robust. After about 6 to 7 months of age, preterms’ dishabituation scores are reportedly no longer different from those of terms (Rose, 1980, 1983; Rose, Gottfried, & Bridger, 1978, 1979). It should be noted that empirical evidence on older preterms’ dishabituation performance is poor and is primarily based on tests with abstract 2D stimuli.
4.3 Preterm Infants with Additional Risks
For samples of preterms exposed to additional complications (see Tables 3 and 4), several studies report disadvantaged visual habituation and dishabituation performance. The most frequently reported risk factors in preterm birth are IVH and RDS complications (e.g., Landry et al., 1985; Rose et al., 1988). The kinds of additional strains preterms are exposed to are summarized in Table 4.
4.3.1 Habituation performance in risk preterms with no IVH or RDS complications
Unfortunately, only a few studies have investigated habituation and dishabituation in samples of preterms who had experienced few risk factors. Effect size comparing terms’ and preterms’ habituation results could be derived for the study conducted by Spungen, Kurtzberg, and Vaughan (1985). The effect size was large, d > 0.80 (p = .001). Spungen et al. tested infants in the neonatal period. Analogous to investigations with non-risk preterms (e.g., Friedman et al., 1981), the study revealed reduced habituation performance. Generally, beyond the neonatal period, visual habituation in risk preterms (with no IVH or RDS complications) appears to be similar to that in terms (Caron & Caron, 1981; Holmes et al., 1989).
4.3.2 Habituation performance in risk preterms with IVH and/or RDS complications
Neither IVH nor RDS complications automatically result in habituation problems. Effect sizes in the studies which found significant differences between preterms and terms were predominantly medium. In Rose et al. (1988), when tested with naturalistic faces and geometric 3D forms, no difference was found between 7-month-old preterms with RDS and 7-month-old terms. With abstract patterns, however, a significant difference between groups, with an effect size of d = 0.49 (p = .01), emerged. In Millar et al. (1991), the use of abstract patterns revealed inferior habituation results in 7.5-month-old preterms. Again, naturalistic faces produced no differences between samples. By contrast, Landry et al. (1985) reported that both 7-month-old preterms with RDS and 7-month-old preterms with RDS plus IVH habituated reliably to abstract patterns. Moreover, the habituation data for the preterms did not deviate significantly from the habituation data for terms.
Rose et al. (2001, 2002), who had tested preterms with a high IVH and RDS rate, also found successful habituation at ages 5, 8, and 13 months. Unlike Landry et al. (1985), who confronted their infant participants with one habituation-dishabituation task, Rose et al. (2001) used a series of comparisons. More specifically, the infants had to solve 5 face comparison tasks and 4 pattern comparison tasks. Despite preterms both habituating and dishabituating, they did not rival the terms’ performance: Only the 13-month-old preterms’ habituation efficiency was completely comparable to that of their term counterparts. The 5- and the 8-month-old preterms’ habituation results were relatively diminished vis-à-vis those of the terms with small to medium effect sizes. Another design was chosen by Rose et al. (2002) who presented infants with multiple pairs of infant faces. From one trial to the next, one face remained constant while the other one changed. This continuous familiarization procedure was run until the infants consistently preferred the novel stimulus (see also Fantz, 1964; Roder, Bushnell, & Sasseville, 2000). Preterms 5, 7, and 12.5 months of age needed more trials than terms to habituate, d = 0.47, d = 0.46, and d = 0.34, respectively.
The study conducted by Ross et al. (1992) more conclusively implies that IVH per se negatively impacts habituation performance in preterms. The authors tested two groups of preterms, one of which suffered from IVH and one which did not. The group with IVH achieved lower habituation scores than the term control group, d = 0.61, whereas there was no difference in habituation between preterms with no IVH and terms.
4.3.3 Dishabituation performance in risk preterms with no IVH or RDS complications
Caron and Caron (1981) administered face-nonface, above-below, same face-different face, and neutral face-smiling face tasks to preterm and term infants 3, 4, 5, and 5.5 months of age, respectively. The preterms had been “in intensive care for complications of varying severity.” During the habituation period, different exemplars of each stimulus type were shown. Following habituation, infants were presented with two new displays, a “familiar” pattern and a “novel” pattern. The familiar pattern required component discrimination, and the novel pattern required configural discrimination. For the component discrimination task, the shape of some or all elements within the pattern was changed, whereas the elements’ overall arrangement within the pattern remained constant. For the configural discrimination, the overall arrangement of the pattern’s elements was changed, whereas the shape of the elements remained constant. Dishabituation was defined as recovery of attention, meaning that looking times toward the test displays were compared to looking times in the last two habituation trials. At 3, 4, and 5 months of age, preterm infants’ responses to the component change did not differ from those of term infants. In contrast, preterms’ sensitivity to the configural change was lower than that of terms. No difference between the groups was observed at 5.5 months. In sum, the preterms’ disadvantage observed until about 5 months of age was restricted to their ability to react to configural changes, but did not undermine their ability to extract component changes. This finding matches results from comparisons between infants who tend to engage in prolonged inspections of mainly one part of a visual pattern (“long-lookers”) and infants who tend to scan all parts of a pattern with short fixations and many shifts (“short-lookers”) (e.g., Bronson, 1991; Frick & Colombo, 1996; Jankowski & Rose, 1997): Like long lookers, during the habituation period preterms might concentrate on examining a few local areas of the stimulus with prolonged fixations and succeed thereby in perceiving component changes, but have difficulties solving configural discrimination tasks. Caron and Caron (1981) did not ascertain a difference between experimental groups at 5.5 months. Hence, the study suggests that preterms’ dishabituation performance remains relatively disadvantaged until about 5 months.
4.3.4 Dishabituation performance in preterms with IVH and/or RDS complications
IVH is thought to entail an impairment of the hippocampus (e.g., Luciana, 2003) and, as a consequence, of cognitive function (as memory). On these grounds, one might expect that preterms with IVH complications display lower dishabituation scores than terms. Experimental findings only partially support this prediction. Effect sizes vary between d = 0.26 and d = 0.72. The lowest effect size was established for 8-month-old infants who were tested by Rose et al. (2001) using abstract patterns. The highest effect size belongs to the investigation conducted by Rose et al. (1988) who found that 7-month-old preterms tested with abstract patterns achieved lower dishabituation scores than terms. This divergence in results indicates that there is no clear relation between effect size and abstract patterns for the same age group. In Rose et al. (2001), where a high incidence of both IVH and RDS was established, lower novelty preferences were observed in the preterm sample. This disadvantage, however, was present at 5 months of age when naturalistic faces served as experimental displays, d = 0.30 (p = .02), but not when abstract patterns were used. At 8 months of age, a disadvantage was observed for both naturalistic faces, d = 0.37 (p = .01), and abstract patterns, d = 0.26 (p = .04). A disadvantage was also noted at 13 months for abstract patterns, d = 0.41 (p = 006), but not for faces. A nearly significant (p = .055), but robust (d = 0.64) disadvantage in visual dishabituation was found by Landry et al. (1985) for 7-month-old preterms with both IVH and RDS. For a second group of preterms with RDS only, no group difference emerged.
Given that Landry et al. (1985) presented RDS infants with abstract patterns (black dots), one might assume that, as found with non-risk preterms, abstract patterns are unsuited for detecting dishabituation disadvantages in preterms with RDS. However, Millar et al. (1991) found disadvantages in 7.5-month-old preterms with RDS complications when using polychromatic lines. Possibly, the addition of salient features like color to abstract patterns might reveal differences between preterms and terms with these stimuli. Millar et al. (1991) also showed that the use of faces is not advantageous because the authors did not establish a disadvantage with this kind of experimental stimulus material. A special stimulus was utilized by Ross et al. (1992). Ten-month-old preterms with IVH were as good as were terms at distinguishing between a line drawing of a face and a scrambled version of the line drawing. Unfortunately, comparability of samples was restricted because preterm age was not corrected.
5. Discussion and Conclusions
The main goal of this meta-analysis was to review studies of visual habituation-dishabituation performance of preterm infants, especially compared to that of terms. Preterms were divided into those without additional medical risk factors (Tables 1 and 2) and those with additional risk factors (Tables 3 and 4).
5.1 Meta-analytical Results from Studies with Non-risk Preterm Infants
The following five conclusions can be drawn for preterms in whom no additional disorders were observed (see also Tables 1 and 2):
Overall, most studies with non-risk preterms do not find significant differences in either habituation or dishabituation performance compared with term infants. Furthermore, in most studies, patterns of habituation and dishabituation in nonrisk preterms do not differ from those obtained from their term counterparts. If a significant effect was discerned, the size of the effect was predominantly medium.
In many studies, abstract two-dimensional patterns serve as experimental stimuli. This raises the question of whether the preterms in these studies were disadvantaged to terms or whether conclusion (a) is an artifact of using mainly simple abstract two-dimensional patterns, which might generally fail to elicit group differences in the development of mental functions. Some studies with risk preterms reveal diminished habituation and dishabituation performance when using abstract patterns. Accordingly, abstract patterns are apparently suited to reveal disadvantages in preterms, meaning that the lack of differences between low-risk preterms and their term counterparts may point to there being no diminished habituation-dishabituation capabilities in preterm samples. Nevertheless, systematic research is needed to investigate what kind of stimuli can be successfully employed to reveal disadvantages in both low- and high-risk preterms.
Term babies’ habituation performance exceeds that of preterms when assessed during the neonatal period. This observation can be regarded as robust, not only because it obtains in all existing studies with neonates, but particularly because these studies used different stimulus materials. Furthermore, for two out of four studies with neonates, effect sizes could be determined. These effect sizes indicated medium, d = 0.51 (Kopp et al., 1975) and large group differences, d = 0.84 (Friedman et al., 1981).
Beyond the neonatal period, disadvantages in preterms’ visual habituation tend to attenuate. It should be noted that looking behavior might be based on different processes at different ages. Possibly, look durations during the first weeks are biased by alertness processes, which are assumed to strongly influence look durations during the first weeks of life (e.g., Colombo, 2001), and longer looking in preterms on the expected due date might be attributable to higher overall alertness (van de Weijer-Bergsma et al., 2008). After the neonatal period, driven by the posterior attentional system, duration of looking during the habituation phase might be a purer measure of stimulus processing, and observed non-significant differences between preterms’ and terms’ habituation scores might reflect equal encoding capabilities.
Some studies report a disadvantage in preterms’ dishabituation abilities. From about 6 months of age on, however, the disadvantage in preterms’ visual dishabituation has attenuated.
In sum, prematurity per se does not inevitably entail long-lasting delays in the development of non-risk infants’ habituation-dishabituation skills. The results for preterms with additional risk factors, however, point to more concerning delays in cognitive development.
5.2 Meta-analytic Results from Studies with Risk Preterm Infants
In general, for samples of preterms who have additional risks, many studies report inferior visual habituation and dishabituation results (see Tables 3 and 4). Studies with high-risk preterm samples were subdivided into those testing preterms with IVH or RDS problems and those testing preterms with other complications such as neonatal jaundice or cardiac anomalies. Generally, the first group of preterms displays poorer habituation-dishabituation scores than the second group of preterms.
Neither IVH nor RDS complications automatically eventuate in adverse preterm habituation and dishabituation. On the whole, however, researchers suggest that both habituation and dishabituation performance in preterms who experience these complications is diminished at least during the first year of life. Effect sizes were mainly medium for habituation measures and small to medium for dishabituation measures. The high incidence of lowered habituation-dishabituation scores in these risk preterms, as compared to the scores in non-risk preterms or in preterms with other handicaps, provides evidence that IVH and RDS complications might exert a strong negative impact on cognitive development.
For preterms who were exposed to risk factors other than IVH and RDS complications, visual habituation may be disadvantaged during the neonatal period only.
Furthermore, for these preterms, disadvantages in the ability to dishabituate start to remit by about 5 months. The results for high-risk preterms who did not experience IVH or RDS complications are, therefore, basically the same as for preterms without additional risk factors.
The lack of differences between preterms with no additional strains and preterms with complications other than IVH or RDS problems also indicates that additional complications like abnormal tone or cardiac anomalies apparently do not adversely affect preterms’ cognitive development. To elucidate the impact of perceptual, motor, social, and emotional (risk) factors on preterms’ short- and long-term cognitive development, it is indispensible to carefully pinpoint all available information on these factors in future research.
5.3 Visual Habituation and Dishabituation as Early Cognitive Measures in Preterm Samples
In light of the results of this review, preterms’ dishabituation performance is generally more delayed than is their habituation performance. One major risk factor to preterms is intraventricular hemorrhage. IVH can impair the hippocampus, which is assumed to contribute to (recognition) memory (e.g., Axmacher, Schmitz, Wagner, Elger, & Fell, 2008; Kirwan et al., 2008; Kumaran & Maguire, 2008; Nelson, 1997). Kavšek (2004b) found a robust correlation of .50 between dishabituation measures and later cognitive outcomes for risk samples. For non-risk infants, this correlation amounted to .32. This difference might be accounted for by a higher long-term stability of latent processes assessed by dishabituation tasks, if these latent processes are damaged. In other words, disadvantages in those preterms’ latent processes, which generate both overt dishabituation behavior as well as later cognitive outcome scores, might persist, thereby entailing a high statistical association between early and later manifest test scores. In a study with VLBW preterms, Ortiz-Mantilla et al. (2008) found that both infant novelty preference and speed of processing were related to children’s later cognitive abilities. Furthermore, these associations were more robust in preterms than in a term control group. The longitudinal research on preterms’ and terms’ development conducted by Rose et al. (2005, 2008) confirms that visual recognition memory is well suited to predict later general developmental level as assessed by the Bayley Scales of Infant Development. Rose, Feldman, and Jankowski (2009) extended those results with findings that infant memory, including visual recognition memory, is related to 36-month language scores. In sum, infant visual dishabituation tasks may be useful in the identification of early cognitive disadvantages in risk preterm infants and might be employed to predict their later cognitive achievement.
From a clinical perspective, it is also relevant to explore whether infant habituation and dishabituation, as early markers of basic cognitive processes, can be improved. Research has shown that cognitive, emotional, and behavioral development in preterms is influenced by endogenous factors and by environmental variables (e.g., Sesma & Georgieff, 2003). More specifically, caregivers’ scaffolding behaviors, such as directing the infant’s attention to an object and providing appropriate levels of stimulation during interaction, play a crucial role in preterm infant development (e.g., Bacharach & Baumeister, 1998; Schmidt & Lawson, 2002; Taylor, Anthony, Aghara, Smith, & Landry, 2008; Veddovi, Gibson, Kenny, Bowen, & Starte, 2004). Research should make an effort to identify the strategies by which parents can compensate and promote their preterm infants’ delayed development (e.g., Dilworth-Bart, Poehlmann, Hilgendorf, Miller, & Lambert, 2009; Landry, Garner, Swank, & Baldwin, 1996; Smith, Landry, Swank, & Baldwin, 1996; Weiss, Wilson, Seed, & Paul, 2001). Beckwith, Cohen, and their colleagues observed both preterm infants and caregivers’ behaviors in their homes (Beckwith & Cohen, 1984; Beckwith, Cohen, Kopp, Parmelee, & Marcy, 1976). Development of the preterms was then followed longitudinally (e.g., Cohen, 1995; Cohen et al., 1996; Cohen, Parmelee, Beckwith, & Sigman, 1986; Sigman et al., 1997; Sigman et al., 1991). The original preterm sample consisted of infants with a gestational age at birth of 37 weeks or less and a birth weight of 2500 g or less who suffered from various medical complications (see Sigman, 1983). Cognitive performance at 18 years of age was predicted by fixation duration in infancy (Sigman et al., 1997). Furthermore, this relation was moderated by early maternal stimulation. More specifically, infants with short look durations whose mothers displayed a high vocalization rate had higher scores as adolescents than infants with longer fixation durations whose mothers vocalized less to them.
From a theoretical point of view, the differential sensitivities of habituation and dishabituation in revealing differences between preterms and terms found in the present review argue for a modular view of habituation-dishabituation processes (e.g., Colombo & Janowsky, 1998). Such a view articulates with the comparator model, according to which habituation reflects the ability to encode stimulus information, whereas dishabituation taps the ability to extract the difference between the memory trace of the habituation stimulus and novel visual information.
In accord with the comparator model, the present review hypothesized that preterms’ habituation and dishabituation scores should be lower than those of terms, if these scores are manifestations of basic cognitive processes. Altogether, the studies listed in Tables 1–4, in which differences between preterms and terms are enumerated, confirm this prediction.
It should be noted that several studies did not observe that preterms lag behind terms, even if high-risk preterms served as participants (e.g., Landry et al., 1985). Reasons for the variability of results are, for the most part, unclear. They could include unattractive and therefore improper stimuli and insensitive testing procedures. Future studies should systematically elucidate the role of kind, degree, and number of preterm dysfunctions as well as of age, stimulus material, and habituation-dishabituation procedure. An early promising approach was pursued by Caron and Caron (1981), who tested infants between 3 and 5.5 months of age for their ability to respond to both component and configural stimulus differences (see also Caron, Caron, & Glass, 1983). Unlike term infants, in the first 5 months preterms displayed a significantly diminished capacity to extract configural stimulus differences.
Another procedure to increase the likelihood of revealing more exact habituation and dishabituation performance is to test infants in multiple tasks in lieu of testing them in only one habituation-dishabituation task. Indeed, with a battery of tasks, Rose et al. (2001) ascertained group differences in 5-, 8-, and 13-month-old preterm and term infants (see Table 3). Increasing the number of tasks can also improve reliability of habituation-dishabituation measures and, as a consequence, their predictive power.
5.4 Future Directions
One problem researchers face when trying to identify the cause of poor developmental outcomes among preterm infants is that risk factors co-occur. Previous work has attempted to determine whether it is prematurity itself, or factors associated with prematurity, which put some preterm infants at increased risk for a variety of disadvantages whilst leaving others relatively unimpaired. Preterm infants are exposed to the extrauterine environment up to 3 months before normative biological expectations. In the United States, prematurity and low birth weight are linked to socioeconomic disadvantage (Paneth, 1995). Preterm births are more common in poor, ill-nourished, and socially stressed families, and it is not known how great an impact these factors have, separately or together. The caregiving environment of preterm infants has been described as less than optimal, with more intrusive, less sensitive and responsive, and less mutually satisfying interactions (Brachfeld et al, 1980; Feldman & Eidelman, 2006; Forcada-Guex, Pierrehumbert, Borghini, Moessinger & Muller-Nix, 2006; Glazebrook et al., 2007; Holditch-Davis, Schwartz, Black & Scher, 2007). Studies of healthy preterm infants and mothers consistently show that infants are more passive and reactive, and that their mothers are more active and directive, than are term infants of comparable age and their mothers (Teti, O’Connell, & Reiner, 1996). Feldman and Eidelman (2006) found that preterm infants, whose mothers showed more intrusive behavior that was uncoordinated with infant state, level of social engagement, or the infant’s cues, displayed poorer cognitive functioning at 24 months. Preterm babies who grow up in enriching, supportive homes do better, whereas those in more deprived environments develop more poorly (Bradley et al., 1994; Forcada-Guex et al., Goldberg, & DiVitto, 2002). Therefore, the environments in which preterm infants are reared are not only at risk due to socioeconomic disadvantage but also due to the nature of the delivery (and subsequent NICU stay) and non-optimal parent-infant interactions. Many preterm and low birth weight infants are at both medical and environmental risk.
In 1981 only 9.4% of births were preterm in the United States (Davidoff et al., 2006). NHS Maternity Statistics for 2006 showed that approximately 7% of births in England were preterm based on gestational age. According to the European Perinatal Health Report, in 2004, about 8.9% of births in Germany and 7% of births in Slovenia had a gestational age < 37 weeks (EURO-PERISTAT Project, 2008). In addition, Steer (2005) claimed the main burden for preterm birth exists in developing countries. There is little accurate worldwide data due to differential use of gestational age and birth weight to define preterm birth by countries, with developing countries tending to rely more on birth weight than gestational age (Behrman & Butler, 2006). Iatrogenic preterm birth occurs in about 25% (range 8.7%–35.2%) of all preterm births, PPROM accounts for another 25% (range 7.1%–51.2%), and the final 50% of preterm births is accounted for by idiopathic preterm birth (range 23.2%–64.1%). Iatrogenic preterm birth, due to maternal illness or developing fetal compromise, is most common in developed countries and is responsible for almost half of births at 28 to 35 weeks’ gestation (Steer, 2005). PPROM occurs more often in disadvantaged populations, with infection usually regarded as the main cause. Idiopathic preterm birth is more frequent in populations without established risk factors. Within countries, etiologies of preterm birth differ with each infant having a unique combination of risk factors and exposures (Behrman & Butler, 2006).
By highlighting the potential of habituation-dishabituation measures to reveal differences between preterms and terms, the present review points to the value of constructing new infant assessments using the habituation-dishabituation paradigm. Such tests should evaluate habituation and dishabituation separately because both measures are distinguished by sufficient effect sizes. Moreover, the predictive validity of both measures should be high to secure that they assess long-term disadvantages. Our review shows that preterms can be successfully tested, even during the neonatal period, making it possible very early to identify and then foster preterms who are at risk for cognitive delays.
Acknowledgments
We thank T. Taylor.
Footnotes
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Contributor Information
Michael Kavšek, Email: kavsek@uni-bonn.de.
Marc H. Bornstein, Email: Marc_H_Bornstein@nih.gov.
References
- Allin M. Brain growh in preterm babies. Lancet. 2006;5:812–813. doi: 10.1016/S1474-4422(06)70560-9. [DOI] [PubMed] [Google Scholar]
- Allin M, Nosarti C, Narberhaus A, Walshe M, Frearson S, Kalpakidou A, et al. Growth of the corpus callosum in adolescents born preterm. Archives of Pediatrics & Adolescent Medicine. 2007;161:1183–1189. doi: 10.1001/archpedi.161.12.1183. [DOI] [PubMed] [Google Scholar]
- Allin M, Walshe M, Fern A, Nosarti C, Cuddy M, Rifkin L, et al. Cognitive maturation in preterm and term born adolescents. Journal of Neurology, Neurosurgery & Psychiatry. 2008;79:381–386. doi: 10.1136/jnnp.2006.110858. [DOI] [PubMed] [Google Scholar]
- Anderson P, Doyle LW the Victorian Infant Collaborative Study Group. Neurobehavioral outcomes of school-age children born extremely low birth weight or very preterm in the 1990s. Journal of the American Medical Association. 2003;289:3264–3272. doi: 10.1001/jama.289.24.3264. [DOI] [PubMed] [Google Scholar]
- Anderson PJ, Doyle LW. Cognitive and educational deficits in children born extremely preterm. Seminars in Perinatology. 2008;32:51–58. doi: 10.1053/j.semperi.2007.12.009. [DOI] [PubMed] [Google Scholar]
- Arterberry ME, Bornstein MH. Variability and its sources in infant categorization. Infant Behavior and Development. 2002;25:515–528. [Google Scholar]
- Atkinson J, Braddick O. Visual and visuocognitive development in children born very prematurely. Progress in Brain Research. 2007;164:123–149. doi: 10.1016/S0079-6123(07)64007-2. [DOI] [PubMed] [Google Scholar]
- Axmacher N, Schmitz DP, Wagner T, Elger CE, Fell J. Interactions between medial temporal lobe, prefrontal cortex, and inferior temporal regions during visual working memory: A combined intracranial EEG and Functional Magnetic Resonance Imaging study. The Journal of Neuroscience. 2008;28:7304–7312. doi: 10.1523/JNEUROSCI.1778-08.2008. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Aylward GP. Neurodevelopmental outcomes of infants born prematurely. Journal of Developmental and Behavioral Pediatrics. 2005;26:427–440. doi: 10.1097/00004703-200512000-00008. [DOI] [PubMed] [Google Scholar]
- Bacharach VR, Baumeister AA. Direct and indirect effects of maternal intelligence, maternal age, income, and home environment on intelligence of preterm, low-birth-weight children. Journal of Applied Developmental Psychology. 1998;19:361–375. [Google Scholar]
- Beauchamp MH, Thompson DK, Howard K, Doyle LW, Egan GF, Inder TE, et al. Preterm infant hippocampal volumes correlate with later working memory deficits. Brain: A Journal of Neurology. 2008;131:2986–2994. doi: 10.1093/brain/awn227. [DOI] [PubMed] [Google Scholar]
- Beck S, Wojdyla D, Say L, Betran AP, Merialdi M, Requejo JH, et al. WHO systematic review on maternal mortality and morbidity: The global burden of preterm birth. The Bulletin of the World Health Organization. 2009;88 doi: 10.2471/BLT.08.062554. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Beckwith L, Cohen SE. Home environment and cognitive competence in preterm children in the first five years. In: Gottfried AW, editor. Home environment and early mental development: Longitudinal research. Orlando, FL: Academic Press; 1984. pp. 235–272. [Google Scholar]
- Beckwith L, Cohen SE, Kopp CB, Parmelee AH, Marcy TG. Caregiver-infant interaction and early cognitive development in preterm infants. Child Development. 1976;47:579–587. [Google Scholar]
- Behrman RE, Butler AS, editors. Preterm birth: Causes, consequences, and prevention. Washington, DC: National Academies Press; 2006. [PubMed] [Google Scholar]
- Berg WK, Berg KM. Psychophysiological development in infancy: State, startle, and attention. In: Osofsky JD, editor. Handbook of infant development. New York: Wiley; 1987. pp. 238–317. [Google Scholar]
- Bhutta AT. Behavioral and cognitive outcomes of ex-preterm children. Italian Journal of Pediatrics. 2004;30:226–232. [Google Scholar]
- Bhutta AT, Anand KJS. Abnormal cognition and behaviour in preterm neonates linked to smaller brain volumes. Trends in Neurosciences. 2001;24:129–130. doi: 10.1016/s0166-2236(00)01747-1. [DOI] [PubMed] [Google Scholar]
- Bhutta AT, Cleves MA, Casey PH, Cradock MM, Anand KJ. Cognitive and behavioral outcomes of school age children who were born preterm: A meta-analysis. Journal of the American Medical Association. 2002;288:728–737. doi: 10.1001/jama.288.6.728. [DOI] [PubMed] [Google Scholar]
- Blasco PA. Preterm birth: To correct or not to correct. Developmental Medicine and Child Neurology. 1989;31:816–826. doi: 10.1111/j.1469-8749.1989.tb04080.x. [DOI] [PubMed] [Google Scholar]
- Boardman JP, Counsell SJ, Rueckert D, Hajnal IV, Bhaha KK, Srinivasan L, et al. Early growth in brain volume is preserved in the majority of preterm infants. Annals of Neurology. 2007;62:185–192. doi: 10.1002/ana.21171. [DOI] [PubMed] [Google Scholar]
- Bonin M, Pomerleau A, Malcuit G. A longitudinal study of visual attention and psychomotor development in preterm and full-term infants during the first six months of life. Infant Behavior and Development. 1998;21:103–118. [Google Scholar]
- Bornstein MH. Habituation of attention as a measure of visual information processing in human infants: Summary, systematization, and synthesis. In: Gottlieb G, Krasnegor NA, editors. Measurement of audition and vision in the first year of postnatal life: A methodological overview. Norwood, NJ: Ablex; 1985. pp. 253–300. [Google Scholar]
- Bornstein MH. Stability in mental development from early life: Methods, measures, models, and myths. In: Simion F, Butterworth G, editors. The development of sensory, motor and cognitive capacities in early infancy. Hove: Psychology Press; 1998. pp. 301–331. [Google Scholar]
- Bornstein MH, Benasich AA. Infant habituation: Assessments of individual differences and short-term reliability at five months. Child Development. 1986;57:87–99. doi: 10.1111/j.1467-8624.1986.tb00009.x. [DOI] [PubMed] [Google Scholar]
- Bornstein MH, Colombo J. Infant cognitive functioning and child mental development. In: Pauen S, Bornstein MH, editors. Early Childhood Development and Later Achievement. New York: Cambridge University Press; 2010. pp. xx–xx. [Google Scholar]
- Bornstein MH, Hahn C-S, Bell C, Haynes OM, Slater A, Golding J, Wolke D ALSPAC Study Team. Stability in cognition across early childhood. A developmental cascade. Psychological Science. 2006;17:151–158. doi: 10.1111/j.1467-9280.2006.01678.x. [DOI] [PubMed] [Google Scholar]
- Bornstein MH, Pêcheux MG, Lécuyer R. Visual habituation in human infants: Development and rearing circumstances. Psychological Research. 1988;50:130–133. doi: 10.1007/BF00309213. [DOI] [PubMed] [Google Scholar]
- Bornstein MH, Ruddy M. Infant attention and maternal stimulation: Prediction of cognitive and linguistic development in singletons and twins. In: Bouma H, Bouwhuis D, editors. Attention and performance. London: Erlbaum; 1984. pp. 433–445. [Google Scholar]
- Bornstein MH, Sigman MD. Continuity in mental development from infancy. In: Oates J, Sheldon S, editors. Cognitive development in infancy. Hove: Erlbaum; 1987. pp. 249–284. [Google Scholar]
- Brachfeld S, Goldberg S, Sloman J. Parent-infant interaction in free play at 8 and 12 months: Effects of rematurity and immaturity. Infant Behaviour and Development. 1980;3:289–305. [Google Scholar]
- Bradley RH, Whiteside L, Mundfrom DJ, Casey PH, Kelleher KJ, Pope SK. Early indications of resilience and their relation to experience in the home environment of low birthweight, premature, children living in poverty. Child Development. 1994;65:346–360. [PubMed] [Google Scholar]
- Brandt I, Sticker EJ. Bedeutung der Alterskorrektur bei Frühgeborenen. Monatsschrift für Kinderheilkunde. 1991;139:16–21. [PubMed] [Google Scholar]
- Bronson GW. Infant differences in rate of visual encoding. Child Development. 1991;62:44–54. [PubMed] [Google Scholar]
- Buchner A, Erdfelder E, Faul F. How to Use G*Power [WWW document] 1997 Available from: URL: http://www.psycho.uni-duesseldorf.de/aap/projects/gpower/how_to_use_gpower.html.
- Caravale B, Tozzi C, Albino G, Vicari S. Cognitive development in low risk preterm infants at 3–4 years of life. Archives of Disease in Childhood: Fetal Neonatal Edition. 2005;90:F474–F479. doi: 10.1136/adc.2004.070284. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Carmody DP, Bendersky M, Dunn SM, DeMarco JK, Hegyi T, Hiatt M, et al. Early risk, attention, and brain activation in adolescents born preterm. Child Development. 2006;77:384–394. doi: 10.1111/j.1467-8624.2006.00877.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Caron RF, Caron AJ. Degree of stimulus complexity and habituation of visual fixation in infants. Psychonomic Science. 1969;14:78–79. [Google Scholar]
- Caron AJ, Caron RF. Processing of relational information as an index of infant risk. In: Friedman SL, Sigman M, editors. Preterm birth and psychological development. New York: Academic Press; 1981. pp. 219–240. [Google Scholar]
- Caron AJ, Caron RF, Glass P. Responsiveness to relational information as a measure of cognitive functioning in nonsuspect infants. In: Field T, Sostek A, editors. Infants born at-risk: Physiological, perceptual, and cognitive processes. New York: Grune & Stratton; 1983. pp. 181–209. [Google Scholar]
- Case-Smith J, Butcher L, Reed D. Parents’ report of sensory responsiveness and temperament in preterm infants. The American Journal of Occupational Therapy. 1998;52:547–555. doi: 10.5014/ajot.52.7.547. [DOI] [PubMed] [Google Scholar]
- Cohen J. Statistical power analysis for the behavioral sciences. New York: Academic Press; 1977. (revised edition) [Google Scholar]
- Cohen LB. Examination of habituation as a measure of aberrant infant development. In: Friedman SL, Sigman M, editors. Preterm birth and psychological development. New York: Academic Press; 1981. pp. 241–253. [Google Scholar]
- Cohen SE. Biosocial factors in early infancy as predictors of competence in adolescents who were born prematurely. Journal of Developmental and Behavioral Pediatrics. 1995;16:36–41. [PubMed] [Google Scholar]
- Cohen SE, Beckwith L, Parmelee AH, Sigman M, Asarnow R, Espinosa MP. Prediction of low and normal school achievement in early adolescents born preterm. Journal of Early Adolescence. 1996;16:46–70. [Google Scholar]
- Cohen SE, Parmelee AH. Prediction of five-year Stanford-Binet scores in preterm infants. Child Development. 1983;54:1242–1253. [PubMed] [Google Scholar]
- Cohen SE, Parmelee AH, Beckwith L, Sigman MD. Cognitive development in preterm infants: Birth to 8 years. Journal of Developmental and Behavioral Pediatrics. 1986;7:102–110. doi: 10.1097/00004703-198604000-00006. [DOI] [PubMed] [Google Scholar]
- Colombo J. Infant cognition: Predicting later intellectual functioning. Newbury Park, CA: Sage; 1993. [Google Scholar]
- Colombo J. On the neural mechanisms underlying developmental and individual differences in visual fixation in infancy: Two hypotheses. Developmental Review. 1995;15:97–135. [Google Scholar]
- Colombo J. The development of visual attention in infancy. Annual Review of Psychology. 2001;52:337–367. doi: 10.1146/annurev.psych.52.1.337. [DOI] [PubMed] [Google Scholar]
- Colombo J. Infant attention grows up: The emergence of a developmental cognitive neuroscience perspective. Current Directions in Psychological Science. 2002;11:196–200. [Google Scholar]
- Colombo J, Harlan JE, Mitchell DW, Richman WA, Maikranz JM, Shaddy DJ. Look duration in infancy: Evidence for a triphasic developmental course. Poster presented at the Biennial Meeting of the Society for Research in Child Development; Albuquerque, NM. 1999. [Google Scholar]
- Colombo J, Janowsky JS. A cognitive neuroscience approach to individual differences in infant attention and recognition memory. In: Richards JE, editor. The cognitive neuroscience of attention: Developmental perspectives. Hillsdale, NJ: Erlbaum; 1998. pp. 363–392. [Google Scholar]
- Colombo J, Mitchell DW. Infant visual habituation. Neurobiology of Learning and Memory. 2009;92:225–234. doi: 10.1016/j.nlm.2008.06.002. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Colombo J, Mitchell D, Horowitz FD. Infant visual attention in the paired-comparison paradigm: Test-retest and attention-performance relations. Child Development. 1988;59:1198–1210. doi: 10.1111/j.1467-8624.1988.tb01489.x. [DOI] [PubMed] [Google Scholar]
- Colombo J, Richman WA, Shaddy DJ, Greenhoot AF, Maikranz JM. Heart rate-defined phases of attention, look duration, and infant performance in the paired-comparison paradigm. Child Development. 2001;72:1605–1616. doi: 10.1111/1467-8624.00368. [DOI] [PubMed] [Google Scholar]
- Colombo J, Shaddy DJ, Richman WA, Maikranz JM, Blaga OM. The developmental course of habituation in infancy and preschool outcome. Infancy. 2004;5:1–38. [Google Scholar]
- Constable RT, Ment LR, Vohr BR, Kesler SR, Fulbright RK, Lacadie C, et al. Prematurely born children demonstrate white matter microstructural differences at 12 years of age, relative to term control subjects: An investigation of group and gender effects. Pediatrics. 2008;121:306–316. doi: 10.1542/peds.2007-0414. [DOI] [PubMed] [Google Scholar]
- Courage ML, Reynolds GD, Richards JE. Infants’ attention to patterned stimuli: Developmental change from 3 to 12 months of age. Child Development. 2006;77:680–695. doi: 10.1111/j.1467-8624.2006.00897.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cyphers LH, Fulker DW, Plomin R, DeFries JC. Cognitive abilities in the early school years: No effects of shared environment between parents and offspring. Intelligence. 1989;13:369–386. [Google Scholar]
- Davidoff MJ, Dias T, Damus K, Russell R, Bettegowda VR, Dolan S, et al. Changes in the gestational age distribution among U.S. Singleton births: Impact on rates of late preterm birth, 1992 to 2002. Seminars in Perinatology. 2006;30:8–15. doi: 10.1053/j.semperi.2006.01.009. [DOI] [PubMed] [Google Scholar]
- de Haan M, Bauer PJ, Georgieff MK, Nelson CA. Explicit memory in low-risk infants aged 19 months born between 27 and 42 weeks of gestation. Developmental Medicine and Child Neurology. 2000;42:304–312. doi: 10.1017/s0012162200000542. [DOI] [PubMed] [Google Scholar]
- Dilworth-Bart J, Poehlmann J, Hilgendorf AE, Miller K, Lambert H. Maternal scaffolding and preterm toddlers’ visual-spatial processing and emerging working memory. Journal of Pediatric Psychology. 2009:1–12. doi: 10.1093/jpepsy/jsp048. [DOI] [PMC free article] [PubMed] [Google Scholar]
- DiPietro JA, Allen M. Estimation of gestational age in the preterm infant and implications for developmental research. Child Development. 1991;62:1184–1199. [PubMed] [Google Scholar]
- Domsch H, Lohaus A, Thomas H. Influences of information processing and disengagement in infant’s looking behavior. Infant & Child Development 2008 [Google Scholar]
- EURO-PERISTAT Project. European Perinatal Health Report. Data from 2004. 2008 Available from: URL: http://www.europeristat.com.
- Fagan JF, Fantz RL, Miranda SB. Infant’s attention to novel stimuli as a function of postnatal and conceptional age. Paper presented at Society for Research in Child Development Meeting, Minneapolis; Minnesota. 1971. Apr, [Google Scholar]
- Fantz RL. Visual experience in infants: Decreased attention to familiar patterns relative to novel ones. Science. 1964;146:668–670. doi: 10.1126/science.146.3644.668. [DOI] [PubMed] [Google Scholar]
- Fantz RL, Fagan JF, Miranda SB. Early visual selectivity as a function of pattern variables, previous exposure, age from birth and conception, and expected cognitive deficit. In: Cohen LB, Salapatek P, editors. Infant perception: From sensation to cognition. Vol. I: Basic visual processes. New York: Academic Press; 1975. pp. 249–345. [Google Scholar]
- Feldman R. The development of regulatory functions from birth to 5 years: Insights from premature infants. Child Development. 2009;80:544–561. doi: 10.1111/j.1467-8624.2009.01278.x. [DOI] [PubMed] [Google Scholar]
- Feldman R, Eidelman AI. Neonatal state organization, neuromaturation, mother-infant interaction, and cognitive development in small-for-gestational-age premature infants. Pediatrics. 2006;118:869–873. doi: 10.1542/peds.2005-2040. [DOI] [PubMed] [Google Scholar]
- Field TM, Woodson R, Cohen D, Greenberg R, Garcia R, Collins K. Discrimination and imitation of facial expressions by term and preterm neonates. Infant Behavior and Development. 1983;6:485–489. [Google Scholar]
- Forcada-Guex M, Pierrehumbert B, Borghini A, Moessinger A, Muller-Nix C. Early dyadic patterns of mother-infant interactions and outcomes of prematurity at 18 months. Pediatrics. 2006;118:107–114. doi: 10.1542/peds.2005-1145. [DOI] [PubMed] [Google Scholar]
- Foster-Cohen S, Edgin JO, Champion PR, Woodward LJ. Early delayed language development in very preterm infants: Evidence from the MacArthur Bates CDI. Journal of Child Language. 2007;34:655–675. doi: 10.1017/s0305000907008070. [DOI] [PubMed] [Google Scholar]
- Foulder-Hughes LA, Cooke RWI. Motor, cognitive, and behavioural disorders in children born very preterm. Developmental Medicine & Child Neurology. 2003;45:97–103. [PubMed] [Google Scholar]
- Frick JE, Colombo J. Individual differences in infant visual attention: Recognition of degraded visual forms by four-month-olds. Child Development. 1996;67:188–204. [PubMed] [Google Scholar]
- Friedman S, Carpenter GC. Visual response decrement as a function of age of human newborn. Child Development. 1971;42:1967–1973. [PubMed] [Google Scholar]
- Friedman SL, Jacobs BS, Werthmann MW., Jr . Sensory processing in pre- and full-term infants in the neonatal period. In: Friedman SL, Sigman M, editors. Preterm birth and psychological development. New York: Academic Press; 1981. pp. 159–178. [Google Scholar]
- Glazebrook C, Marlow N, Israel C, Croudace T, Johnson S, White IR, et al. Randomised trial of a parenting intervention during neonatal intensive care. Archives of Disease in Childhood – Fetal and Neonatal Edition. 2007;92:F438–F443. doi: 10.1136/adc.2006.103135. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Goldberg S, DiVitto BA. Born too soon: Preterm birth and early development. W. H. Freeman & Company; New York, NY: 1983. [Google Scholar]
- Goldberg S, Di Vitto B. Parenting children born preterm. In: Bornstein M, editor. Handbook of parenting. Vol. 1: Children and parenting. 2. Mahwah, NJ: Erlbaum; 2002. pp. 209–231. [Google Scholar]
- Goldenberg RL, Culhane JF, Iams JD, Romero R. Epidemiology and causes of preterm birth. Lancet. 2008;371:75–84. doi: 10.1016/S0140-6736(08)60074-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gorga D, Stern FM, Ross G, Nagler W. Neuromotor development of preterm and full-term infants. Early Human Development. 1988;18:137–149. doi: 10.1016/0378-3782(88)90050-3. [DOI] [PubMed] [Google Scholar]
- Gottfried AW. Issues concerning the relationship between home environment and early cognitive development. In: Gottfried AW, editor. Home environment and early cognitive development. New York: Academic Press; 1984. pp. 1–4. [Google Scholar]
- Hamilton BE, Martin JA, Sutton PD. National vital statistics reports. 9. Vol. 53. Hyattsville, Maryland: National Center for Health Statistics; 2004. Births: Preliminary data for 2003. [PubMed] [Google Scholar]
- Hedges LV, Olkin I. Statistical methods for meta-analysis. San Diego, CA: Academics Press; 1985. [Google Scholar]
- Hepper PG, Shahidullah S. Habituation in normal and Down’s Syndrome fetuses. The Quarterly Journal of Experimental Psychology. 1992;44B:305–317. doi: 10.1080/02724999208250617. [DOI] [PubMed] [Google Scholar]
- Hintz SR, Kendrick DE, Vohr BR, Poole WK, Higgins RD. Changes in neurodevelopmental outcomes at 18 to 22 months’ corrected age among infants of less than 25 weeks’ gestational age born in 1993–1999. Pediatrics. 2005;115:1645–1651. doi: 10.1542/peds.2004-2215. [DOI] [PubMed] [Google Scholar]
- Holditch-Davis D, Schwartz T, Black BP, Scher M. Correlates of mother-premature infant interactions. Research in Nursing and Health. 2007;30:333–346. doi: 10.1002/nur.20190. [DOI] [PubMed] [Google Scholar]
- Holmes DL, Nagy Reich JN, Gyurke JS. The development of high-risk infants in low-risk families. In: Morrison FJ, Lord C, Keating DP, editors. Applied developmental psychology. Vol. 3: Psychological development in infancy. San Diego, CA: Academic Press; 1989. pp. 81–137. [Google Scholar]
- Hunter MA, Ames EW. A multifactor model of infant preferences for novel and familiar stimuli. Advances in Infancy Research. 1988;5:69–95. [Google Scholar]
- Hunter MA, Ames EW, Koopman R. Effects of stimulus complexity and familiarization time on infant preferences for novel and familiar stimuli. Developmental Psychology. 1983;19:338–352. [Google Scholar]
- Isaacs EB, Lucas A, Chong WK, Wood SJ, Johnson CL, Marshall C, et al. Hippocampal volume and everyday memory in children of very low birthweight. Pediatric Research. 2000;47:713–720. doi: 10.1203/00006450-200006000-00006. [DOI] [PubMed] [Google Scholar]
- Jackson RA, Gibson KA, Wu YW, Croughan MS. Perinatal outcomes in singletons following in vitro fertilization: A meta-analysis. Obstretics & Gynecology. 2004;103:551–563. doi: 10.1097/01.AOG.0000114989.84822.51. [DOI] [PubMed] [Google Scholar]
- Jacobson SW, Jacobson JL, Sokol RJ, Martier SS, Ager JW. Prenatal alcohol exposure and infant information processing ability. Child Development. 1993;64:1706–1721. [PubMed] [Google Scholar]
- Jacobson SW, Jacobson JL, Sokol RJ, Martier SS, Chiodo LM. New evidence for neurobehavioral effects of in utero cocaine exposure. The Journal of Pediatrics. 1996;129:581–590. doi: 10.1016/s0022-3476(96)70124-5. [DOI] [PubMed] [Google Scholar]
- Jankowski JJ, Rose SA. The distribution of visual attention in infants. Journal of Experimental Child Psychology. 1997;65:127–140. doi: 10.1006/jecp.1996.2363. [DOI] [PubMed] [Google Scholar]
- Jeffrey WE. Habituation as a mechanism for perceptual development. In: Tighe TJ, Leaton RN, editors. Habituation. Perspectives from child development, animal behavior, and neurophysiology. New York: Erlbaum; 1976. pp. 279–296. [Google Scholar]
- Kandel EC. In search of memory: The emergence of a new science of mind. New York: W. W. Norton; 2007. [Google Scholar]
- Kaplan PS, Werner JS. Habituation, response to novelty, and dishabituation in human infants: Tests of a dual-process theory of visual attention. Journal of Experimental Child Psychology. 1986;42:199–217. doi: 10.1016/0022-0965(86)90023-8. [DOI] [PubMed] [Google Scholar]
- Kavšek . Infant visual habituation and dishabituation: Recent insights. in preparation. [DOI] [PubMed] [Google Scholar]
- Kavšek MJ. Visuelle Habituation und Dishabituation im Säuglingsalter: Das Komparatormodell. Psychologische Rundschau. 2000;51:178–184. [Google Scholar]
- Kavšek M. Die Reliabilität von visuellen Habituations- und Dishabituationsmaßen. Eine Metaanalyse. Zeitschrift für Entwicklungspsychologie und Pädagogische Psychologie. 2004a;36:83–94. [Google Scholar]
- Kavšek M. Predicting later IQ from infant visual habitation and dishabituation: A meta-analysis. Journal of Applied Developmental Psychology. 2004b;25:369–393. [Google Scholar]
- Khan NZ, Muslima H, Parveen M, Bhattacharya AM, Begum N, Chowdhury, et al. Neurodevelopmental outcomes of preterm infants in Bangladesh. Pediatrics. 2006;118:280–289. doi: 10.1542/peds.2005-2014. [DOI] [PubMed] [Google Scholar]
- Kirschner W, Halle H, Pogonke MA. Kosten der Früh- und Nichtfrühgeburten und die Effektivität und Effizienz von Präventionsprogrammen am Beispiel von BabyCare. Prävention und Gesundheitsförderung. 2009;4:41–50. [Google Scholar]
- Kirwan CB, Wixted JT, Squire LR. Activity in the medial temporal lobe predicts memory strength, whereas activity in the prefrontal cortex predicts recollection. The Journal of Neuroscience. 2008;28:10541–10548. doi: 10.1523/JNEUROSCI.3456-08.2008. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kopp CB, Sigman M, Parmelee AH, Jeffrey WE. Neurological organization and visual fixation in infants at 40 weeks conceptional age. Developmental Psychobiology. 1975;8:165–170. doi: 10.1002/dev.420080208. [DOI] [PubMed] [Google Scholar]
- Kumaran D, Maguire EA. Novelty signals: A window into hippocampal information processing. Trends in Cognitive Sciences. 2008;13:47–54. doi: 10.1016/j.tics.2008.11.004. [DOI] [PubMed] [Google Scholar]
- Landry SH, Garner PW, Swank PR, Baldwin CD. Effects of maternal scaffolding during joint toy play with preterm and full-term infants. Merrill Palmer Quarterly. 1996;42:177–199. [Google Scholar]
- Landry SH, Leslie NA, Fletcher JM, Francis DJ. Visual attention skills of premature infants with and without intraventricular hemorrhage. Infant Behavior and Development. 1985;8:309–321. [Google Scholar]
- Lefebvre F, Glorieux J, St-Laurent-Gagnon T. Neonatal survival and disability rate at age 18 months for infants born between 23 and 28 weeks gestation. American Journal of Obstetrics & Gynecology. 1996;174:833–838. doi: 10.1016/s0002-9378(96)70309-5. [DOI] [PubMed] [Google Scholar]
- Lester BM. Cardiac habituation of the orienting response to an auditory signal in infants of varying nutritional status. Developmental Psychology. 1975;11:432–442. [Google Scholar]
- Lewis M. Attention as a measure of cognitive integrity. In: Lewis M, Taft L, editors. Developmental disabilities: Theory, assessment and intervention. New York: SP Medical and Scientific Books; 1981. pp. 185–212. [Google Scholar]
- Luciana M. Cognitive development in children born preterm: Implications for theories of brain plasticity following early injury. Development and Psychopathology. 2003;15:1017–1047. doi: 10.1017/s095457940300049x. [DOI] [PubMed] [Google Scholar]
- Luciana M, Lindeke L, Georgieff M, Mills M, Nelson CA. Neurobehavioral evidence for working-memory deficits in school-aged children with histories of prematurity. Developmental Medicine & Child Neurology. 1999;41:521–533. doi: 10.1017/s0012162299001140. [DOI] [PubMed] [Google Scholar]
- Luoma L, Herrgảrd E, Martikainen A. Neuropsychological analysis of the visuomotor problems in children born preterm at <=32 weeks of gestation: A 5-year prospective follow-up. Developmental Medicine & Child Neurology. 1998;40:21–30. doi: 10.1111/j.1469-8749.1998.tb15352.x. [DOI] [PubMed] [Google Scholar]
- Macfarlane A, Blondel B. Demographic trends in Western European countries. In: Blickstein I, Keith LG, editors. Multiple pregnancy: Epidemiology, Gestation & perinatal outcome. 2. London: Taylor & Francis; 2005. pp. 11–21. [Google Scholar]
- Marlow N, Wolke D, Bracewell MA, Samara M. Neurologic and developmental disability at six years of age after extremely preterm birth. The New England Journal of Medicine. 2005;352:9–19. doi: 10.1056/NEJMoa041367. [DOI] [PubMed] [Google Scholar]
- Martin JA, Hamilton BE, Sutton PD, Ventura SJ, Menacker F, Kirmeyer S, et al. National vital statistics reports. 6. Vol. 56. Hyattsville, MD: National Center for Health Statistics; 2007. Births: Final data for 2005. [PubMed] [Google Scholar]
- Mash C, Quinn PC, Dobson V, Narter DB. Global influences on the development of spatial and object perceptual categorization abilities: Evidence from preterm infants. Developmental Science. 1998;1:85–102. [Google Scholar]
- Matthews A, Ellis AE, Nelson CA. Development of preterm and full-term infant ability on AB, recall memory, transparent barrier detour, and means-end tasks. Child Development. 1996;67:2658–2676. [PubMed] [Google Scholar]
- Mayes LC, Granger RH, Frank MA, Schottenfeld R, Bornstein MH. Neurobehavioral profiles of neonates exposed to cocaine prenatally. Pediatrics. 1993;91:778–783. [PubMed] [Google Scholar]
- McCall RB, Carriger MS. A meta-analysis of infant habituation and recognition memory performance as predictors of later IQ. Child Development. 1993;64:57–79. [PubMed] [Google Scholar]
- Mewes AU, Huppi PS, Als H, Rybicki FJ, Inder TE, McAnulty GB, et al. Regional brain development in serial magnetic resonance imaging of low-risk preterm infants. Pediatrics. 2006;118:23–33. doi: 10.1542/peds.2005-2675. [DOI] [PubMed] [Google Scholar]
- Millar W, Weir C, Supramaniam G. The relationship between encoding, discriminative capacities and perinatal risk status in 4–12-month old infants. Journal of Child Psychology and Psychiatry and Allied Disciplines. 1991;32:473–488. doi: 10.1111/j.1469-7610.1991.tb00325.x. [DOI] [PubMed] [Google Scholar]
- Moster D, Lie RT, Markestad T. Long-term medical and social consequences of preterm birth. The New England Journal of Medicine. 2008;359:262–273. doi: 10.1056/NEJMoa0706475. [DOI] [PubMed] [Google Scholar]
- Moutquin J. Classification and heterogeneity of preterm birth. BJOG: An International Journal of Obstetrics and Gynaecology. 2003;110:30–33. doi: 10.1016/s1470-0328(03)00021-1. [DOI] [PubMed] [Google Scholar]
- Nadeau L, Tessier R, Boivin M, Lefebvre F, Robaey P. Extremely premature and very low birthweight infants: A double hazard population? Social Development. 2003;12:235–248. [Google Scholar]
- Nelson CA. The neurobiological basis of early memory development. In: Cowan N, editor. The development of memory in childhood. Hove: Psychology Press; 1997. pp. 41–82. [Google Scholar]
- Oberklaid F, Sewell J, Sanson A, Prior M. Temperament and behavior of preterm infants: A six-year follow-up. Pediatrics. 1991;87:854–861. [PubMed] [Google Scholar]
- Ortiz-Mantilla S, Choudhury N, Leevers H, Benasich AA. Understanding language and cognitive deficits in very low birth weight children. Developmental Psychobiology. 2008;50:107–126. doi: 10.1002/dev.20278. [DOI] [PubMed] [Google Scholar]
- Pahnke J. Erfassung kognitiver Fähigkeiten im Säuglingsalter. Aachen: Shaker; 2007. [Google Scholar]
- Paneth NS. The problem of low birth weight. The Future of Children. 1995;5:19–34. [PubMed] [Google Scholar]
- Piper MC, Byrne PJ, Darrah J, Watt MJ. Gross and fine motor development of preterm infants at eight and 12 months of age. Developmental Medicine and Child Neurology. 1989;31:591–597. doi: 10.1111/j.1469-8749.1989.tb04044.x. [DOI] [PubMed] [Google Scholar]
- Roder BJ, Bushnell EW, Sasseville AM. Infants’ preferences for familiarity and novelty during the course of visual processing. Infancy. 2000;1:491–507. doi: 10.1207/S15327078IN0104_9. [DOI] [PubMed] [Google Scholar]
- Rose SA. Enhancing visual recognition memory in preterm infants. Developmental Psychology. 1980;16:85–92. [Google Scholar]
- Rose SA. Differential rates of visual information processing in full term and preterm infants. Child Development. 1983;54:1189–1198. [PubMed] [Google Scholar]
- Rose SA, Feldman JF. Prediction of IQ and specific cognitive abilities at 11 years from infancy measures. Developmental Psychology. 1995;31:685–696. [Google Scholar]
- Rose SA, Feldman JF, Jankowski JJ. Attention and recognition memory in the 1st year of life: A longitudinal study of preterm and full-term infants. Developmental Psychology. 2001;37:135–151. [PubMed] [Google Scholar]
- Rose SA, Feldman JF, Jankowski JJ. Processing speed in the 1st year of life: A longitudinal study of preterm and full-term infants. Developmental Psychology. 2002;38:895–902. doi: 10.1037//0012-1649.38.6.895. [DOI] [PubMed] [Google Scholar]
- Rose SA, Feldman JF, Jankowski JJ. A cognitive approach to the development of early language. Child Development. 2009;80:134–150. doi: 10.1111/j.1467-8624.2008.01250.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rose SA, Feldman JF, Jankowski JJ, Van Rossem R. Pathways from prematurity and infants abilities to later cognition. Child Development. 2005;76:1172–1184. doi: 10.1111/j.1467-8624.2005.00843.x. [DOI] [PubMed] [Google Scholar]
- Rose SA, Feldman JF, Jankowski JJ, Van Rossem R. A cognitive cascade in infancy: Pathways from prematurity to later mental development. Intelligence. 2008;36:367–378. doi: 10.1016/j.intell.2007.07.003. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rose SA, Feldman JF, McCarton CM, Wolfson J. Information processing in seven-month-old infants as a function of risk status. Child Development. 1988;59:589–603. [PubMed] [Google Scholar]
- Rose SA, Gottfried AW, Bridger WH. Cross-modal transfer in infants: Relationship to prematurity and socioeconomic background. Developmental Psychology. 1978;14:643–652. [Google Scholar]
- Rose SA, Gottfried AW, Bridger WH. Effects of haptic cues on visual recognition memory in fullterm and preterm infants. Infant Behavior and Development. 1979;2:55–67. [Google Scholar]
- Rose S, Tamis-LeMonda CS. Visual information processing in infancy: Reflections on underlying mechanisms. In: Balter L, Tamis-LeMonda CS, editors. Child psychology: A handbook of contemporary issues. Philadelphia, PA: Psychology Press/Taylor & Francis; 1999. pp. 64–84. [Google Scholar]
- Rose SA, Wallace IF. Cross-modal and intramodal transfer as predictors of mental development in full-term and preterm infants. Developmental Psychology. 1985a;21:949–962. [Google Scholar]
- Rose SA, Wallace IF. Visual recognition memory: A predictor of later cognitive functioning in preterms. Child Development. 1985b;56:843–852. [PubMed] [Google Scholar]
- Ross G, Lawson K. Commentary: Using the Bayley-II: Unresolved issues in assessing the development of prematurely born children. Developmental and Behavioral Pediatrics. 1997;18:109–111. doi: 10.1097/00004703-199704000-00007. [DOI] [PubMed] [Google Scholar]
- Ross G, Tesman J, Auld PA, Nass R. Effects of subependymal and mild intraventricular lesions on visual attention and memory in premature infants. Developmental Psychology. 1992;28:1067–1074. [Google Scholar]
- Rothbart MK, Bates JE. Temperament. In: Damon W, Lerner RM, Eisenberg N, editors. Handbook of child psychology. Vol. 3: Social, emotional, and personality development. 6. Hoboken, NJ: Wiley; 2006. pp. 99–166. [Google Scholar]
- Ruff HA, Rothbart MK. Attention in early development: Themes and variations. New York: Oxford University Press; 1996. [Google Scholar]
- Salt A, Redshaw M. Neurodevelopmental follow-up after preterm birth: Follow up after two years. Early Human Development. 2006;82:185–197. doi: 10.1016/j.earlhumdev.2005.12.015. [DOI] [PubMed] [Google Scholar]
- Sanjaniemi N, Salokorpi T, Von Wendt L. Temperament profiles and their role in neurodevelopmental assessed preterm children at two years of age. European Child & Adolescent Psychiatry. 1998;7:145–152. doi: 10.1007/s007870050060. [DOI] [PubMed] [Google Scholar]
- Sansavini A, Guarini A, Alessandroni R, Faldella G, Giovanelli G, Salvioli G. Early relations between lexical and grammatical development in very immature Italian preterms. Journal of Child Language. 2006;33:199–216. doi: 10.1017/s0305000905007208. [DOI] [PubMed] [Google Scholar]
- Scarr S, Weinberg RA, Waldman ID. IQ correlations in transracial adoptive families. Intelligence. 1993;17:541–555. [Google Scholar]
- Schmidt CL, Lawson KR. Caregiver attention-focusing and children’s attention-sharing behaviours as predictors of later verbal IQ in very low birthweight children. Journal of Child Language. 2002;29:3–22. doi: 10.1017/s0305000901004913. [DOI] [PubMed] [Google Scholar]
- Schöner G, Thelen E. Using dynamic field theory to rethink infant habituation. Psychological Review. 2006;113:273–299. doi: 10.1037/0033-295X.113.2.273. [DOI] [PubMed] [Google Scholar]
- Sesma HW, Georgieff MK. The effect of adverse intrauterine and newborn environments on cognitive development: The experiences of premature delivery and diabetes during pregnancy. Development and Psychopathology. 2003;15:991–1015. doi: 10.1017/s0954579403000488. [DOI] [PubMed] [Google Scholar]
- Shaddy DJ, Colombo J. Developmental changes in infant attention to dynamic and static stimuli. Infancy. 2004;5:355–365. [Google Scholar]
- Siegel L. Correction for prematurity and its consequences for the assessment of the very low birth weight infant. Child Development. 1983;54:1176–1188. [PubMed] [Google Scholar]
- Sigman MD. Individual differences in infant attention: Relations to birth status and intelligence at five years. In: Field T, Sostek A, editors. Infants born at risk: Physiological, perceptual, and cognitive processes. New York: Grune & Stratton; 1983. pp. 271–293. [Google Scholar]
- Sigman M, Cohen SE, Beckwith L. Why does infant attention predict adolescent intelligence? Infant Behavior and Development. 1997;20:133–140. [Google Scholar]
- Sigman M, Cohen SE, Beckwith L, Asarnow R, Parmelee AH. Continuity in cognitive abilities from infancy to 12 years of age. Cognitive Development. 1991;6:47–57. [Google Scholar]
- Sigman M, Kopp CB, Littman B, Parmelee AH. Infant visual attentiveness as a function of birth condition. Developmental Psychology. 1977;13:431–437. [Google Scholar]
- Sigman M, Kopp CB, Parmelee AH, Jeffrey WE. Visual attention and neurological organization in neonates. Child Development. 1973;44:461–466. [PubMed] [Google Scholar]
- Sigman M, Parmelee AH. Visual preferences of four-month-old premature and full-term infants. Child Development. 1974;45:959–965. [PubMed] [Google Scholar]
- Sirois S, Mareschal D. An interacting systems model of infant habituation. Journal of Cognitive Neuroscience. 2004;16:1352–1362. doi: 10.1162/0898929042304778. [DOI] [PubMed] [Google Scholar]
- Slater A, Morison V. Visual attention and memory at birth. In: Weiss MJS, Zelazo PR, editors. Newborn attention. Biological constraints and the influence of experience. Norwood, NJ: Ablex; 1991. pp. 256–277. [Google Scholar]
- Slater A, Morison V, Rose D. Locus of habituation in the human newborn. Perception. 1983;12:593–598. doi: 10.1068/p120593. [DOI] [PubMed] [Google Scholar]
- Smith KE, Landry SH, Swank PR, Baldwin CD. The relation of medical risk and maternal stimulation with preterm infants’ development of cognitive, language and daily living skills. Journal of Child Psychology and Psychiatry and Allied Disciplines. 1996;37:855–864. doi: 10.1111/j.1469-7610.1996.tb01481.x. [DOI] [PubMed] [Google Scholar]
- Sokolov EN. Perception and the conditioned reflex. Oxford: Pergamon Press; 1963. [Google Scholar]
- Sokolov YN. Orienting reflex as information regulator. In: Leontiev AN, Luria A, Smirnov S, editors. Psychological research in the U S S R. Vol. 1. Moscow: Progress; 1966. pp. 334–360. [Google Scholar]
- Spungen LB, Kurtzberg D, Vaughan HG. Patterns of looking behavior in full-term and low birth weight infants at 40 weeks post-conceptional age. Journal of Developmental and Behavioral Pediatrics. 1985;6:287–294. [PubMed] [Google Scholar]
- Steer P. The epidemiology of preterm labour. BJOG: An International Journal of Obstetrics and Gynaecology. 2005;112:1–3. doi: 10.1111/j.1471-0528.2005.00575.x. [DOI] [PubMed] [Google Scholar]
- Taylor HB, Anthony JL, Aghara R, Smith KE, Landry SH. The interaction of early maternal responsiveness and children’s cognitive abilities on later decoding and reading comprehension skills. Early Education and Development. 2008;19:188–207. [Google Scholar]
- Teti DM, O’Connell MA, Reiner CD. Parenting sensitivity, parental depression and child health: The mediational role of parental self-efficacy. Early Development & Parenting. 1996;5:237–250. [Google Scholar]
- Thompson LA, Detterman DK, Plomin R. Associations between cognitive abilities and scholastic achievement: Genetic overlap but environmental differences. Psychological Science. 1991;2:158–165. [Google Scholar]
- Thompson RF, Spencer WA. Habituation: A model phenomenon for the study of neuronal substrates of behavior. Psychological Review. 1966;73:16–43. doi: 10.1037/h0022681. [DOI] [PubMed] [Google Scholar]
- van de Weijer-Bergsma E, Wijnroks L, Jongmans MJ. Attention development in infants and preschool children born preterm: A review. Infant Behavior and Development. 2008;31:333–351. doi: 10.1016/j.infbeh.2007.12.003. [DOI] [PubMed] [Google Scholar]
- Vanhatalo AM, Ekblad H, Kero P, Erkkola R. Incidence of bronchopulmonary dysplasia during an 11-year period in infants weighing less than 1500 g at birth. Annales Chirurgiae et Gynaecologiae Supplement. 1994;208:113–116. [PubMed] [Google Scholar]
- Veddovi M, Gibson F, Kenny DT, Bowen J, Starte D. Preterm behavior, maternal adjustment, and competencies in the newborn period: What influence do they have at 12 months postnatal age? Infant Mental Health Journal. 2004;25:580–599. [Google Scholar]
- Verma RP. Respiratory distress syndrome of the newborn infant. Obstetrical & Gynecological Survey. 1995;50:542–555. doi: 10.1097/00006254-199507000-00021. [DOI] [PubMed] [Google Scholar]
- Vohr BR, Wright LL, Dusick AM, Mele L, Verter J, Steichen LM, et al. Neurodevelopmental and functional outcomes of extremely low birth weight infants in the National Institute of Child Health and Human Development Neonatal Research Network, 1993–1994. Pediatrics. 2000;105:1216–1226. doi: 10.1542/peds.105.6.1216. [DOI] [PubMed] [Google Scholar]
- Vohr BR, Wright LL, Poole WK, McDonald SA for the NICHD Neonatal Research Network Follow-up Study. Neurodevelopmental outcomes of extremely low birth weight infants <32 weeks’ gestation between 1993 and 1998. Pediatrics. 2005;116:635–643. doi: 10.1542/peds.2004-2247. [DOI] [PubMed] [Google Scholar]
- Volpe JJ. Cerebral white matter injury of the premature infant: More common than you think. Pediatrics. 2003;112:176–180. doi: 10.1542/peds.112.1.176. [DOI] [PubMed] [Google Scholar]
- Weiss SJ, Wilson P, Seed MSJ, Paul SM. Early tactile experience of low birth weight children: Links to later mental health and social adaptation. Infant and Child Development. 2001;10:93–115. [Google Scholar]
- Wiener G, Rider RV, Oppel WC, Fischer LK, Harper PA. Correlates of low birth weight: Psychological status at six to seven years of age. Pediatrics. 1965;35:434–444. [PubMed] [Google Scholar]
- Wilson SL, Cradock MM. Review: Accounting for prematurity in Developmental Assessment and the use of age-adjusted scores. Journal of Pediatric Psychology. 2004;29:641–649. doi: 10.1093/jpepsy/jsh067. [DOI] [PubMed] [Google Scholar]
- Wolke D, Ratschinski G, Ohrt B, Riegel K. The cognitive outcome of very preterm infants may be poorer than often reported: An empirical investigation of how methodological issues make a big difference. European Journal of Pediatrics. 1994;153:906–915. doi: 10.1007/BF01954744. [DOI] [PubMed] [Google Scholar]
- Wood NS, Marlow N, Costeloe K, Chir B, Gibson AT, Wilkinson AR for the EPICure Study Group. Neurologic and developmental disability after extremely preterm birth. The New England Journal of Medicine. 2000;343:378–384. doi: 10.1056/NEJM200008103430601. [DOI] [PubMed] [Google Scholar]
- Woodward LJ, Mogridge N, Wells SW, Inder TE. Can neurobehavioral examination predict the presence of cerebral injury in the very low birth weight infant? Journal of Developmental & Behavioral Pediatrics. 2004;25:326–334. doi: 10.1097/00004703-200410000-00004. [DOI] [PubMed] [Google Scholar]
- Zwicker JG, Harris SR. Quality of life of formerly preterm and very low birth weight infants from preschool age to adulthood: A systematic review. Pediatrics. 2008;121:e366–e376. doi: 10.1542/peds.2007-0169. [DOI] [PubMed] [Google Scholar]