Table 1. Studies included in the systematic review.
| Studies Authors (year) | Groups (sample size) Origin | Gender Number of males (%) | Age (years) M (SD) | Presence of a comorbid disorder to DCD | Attentional or executive function studied | Task(s) used to assess attentional or executive functions | Summary of results |
|---|---|---|---|---|---|---|---|
| Alesi et al. (2019) | DCD (18) TD (18) Schools |
9 (50.0%) 9 (50.0%) |
4.6 (0.9) 4.6 (0.9) |
Exclusion of children with intellectual disability, visual or neurological impairment and neurodevelopment-tal disorders. | Fluency (verbal) Response inhibition (verbal) Working memory (verbal) Working memory (visuospatial) |
BVN-5-11 Stroop Task, Gift Wrap Task, Snack Delay Task Working Memory Tasks: Forward word recall, Selective word recall, Verbal dual task Pathway recall, Selective pathway recall, Visuospatial dual task |
Children with DCD performed significantly more poorly than TD children on both the forward (p = .022) and selective word recalls (p = .05), but the results did not differ significantly for the verbal dual task. They also had lower scores on the three visuo-spatial tasks (p < .05). Children with DCD also performed more poorly than TD children on the BVN-5-11(p = .00). Children with DCD obtained lower scores for both congruent and incongruent stimuli on the Stroop task (p < .01). However, there was no significant difference between DCD and TD children on emotionally-valenced tasks |
| Alloway (2007) | DCD (55; same sample as Alloway, 2011 and Alloway et al., 2009) Schools, referred by health care professio-nals |
44 (80.0%) | 8.8 (1.6) | No mention of exclusion. |
Working memory (verbal) Working memory (visuospatial) |
AWMA: Listening Recall, Counting Recall, Backwards Digit Recall Odd-One-Out, Mr. X, Spatial Span |
49% of sample obtained standard scores of less than 85 on the verbal WM measures. 60% of sample obtained scores of less than 85 on the visuospatial WM measures. The difference between performance on visuospatial and verbal WM measures was not significant. |
| Alloway (2011) | DCD (55; same sample as Alloway, 2007 and Alloway et al., 2009) ADHD (50) TD (50) Schools, referred by health care professio-nals |
44 (80.0%) 43 (86.0%) 30 (60.0%) |
8.8 (1.6) 9.8 (1.0) 9.9 (1.0) |
Exclusion of children diagnosed with behavioral or attentional problems. |
Working memory (verbal) Working memory (visuospatial) |
AWMA: Listening Recall, Counting Recall, Backwards Digit Recall Odd-One-Out, Mr. X, Spatial Span |
The DCD and ADHD groups performed more poorly than the TD group on both verbal and visuospatial WM measures (p < .05). Children with DCD showed deficits on both modalities compared to TD controls. Their WM profile did not differ significantly compared to that of children with ADHD. |
| Alloway & Archibald (2008) | DCD only (11) DCD unselected (12) SLI (11) Schools, referred by health care professio-nals |
8 (72.7%) 8 (66.7%) 7 (63.6%) |
8.9 (1.4) 8.5 (1.6) 8.8 (1.4) |
Exclusion of children diagnosed with ADHD or ASD. Inclusion of children with language or nonverbal reasoning difficulties (DCD unselected group). |
Working memory (verbal) Working memory (visuospatial) |
AWMA: Listening Recall, Counting Recall, Backwards Digit Recall Odd-One-Out, Mr. X, Spatial Span |
The two DCD groups did not significantly differ on their WM profiles. Their performance was more than 1.25 SD below the standardized mean on most tasks. Children in the DCD only group performed significantly worse than children with SLI on the visuospatial WM measures, even when the contribution of receptive language skills was accounted for. Their verbal WM skills were similar. Thus, children in DCD groups had deficits in both WM modalities, whereas those in SLI group only had verbal WM deficits. |
| Alloway et al. (2009) | DCD (55; same sample as Alloway, 2007, 2011) SLI (15) ADHD (83) AS (10) Schools, referred by health care professio-nals |
44 (80.0%) 9 (60.0%) 71 (85.5%) 8 (80.0%) |
8.8 (1.6) 9.2 (1.7) 9.1 (1.1) 8.8 (1.5) |
Exclusion of children diagnosed with behavioral problems. |
Working memory (verbal) Working memory (visuospatial) |
AWMA: Listening Recall, Counting Recall, Backwards Digit Recall Odd-One-Out, Mr. X, Spatial Span |
Children with DCD had significantly lower scores than children with AS on visuospatial WM measures (p < .05), but the difference was attributable to the motor component of the tests. There were no significant differences when comparing with the other clinical groups. On verbal WM measures, there were no differences between groups. |
| Alloway & Temple (2007) | DCD (20) MLD (20) Schools, referred by health care professio-nals |
14 (70.0%) 15 (75.0%) |
9.8 (1.4) 9.8 (1.4) |
No mention of exclusion. |
Working memory (verbal) Working memory (visuospatial) |
AWMA: Listening Recall, Counting Recall, Backwards Digit Recall Odd-One-Out, Mr. X, Spatial Span |
Mean standard scores of children with DCD on all WM tasks were less than 85. Performances of children with DCD were poorer than that of children with MLD on all WM measures (p < .01). Children with DCD showed significant deficits in visuospatial WM, while MLD group performed within age-expected level in this domain. On measures of verbal WM, both groups were impaired. Thus, impaired visuospatial WM seems to be more specific to children with DCD when compared to children with MLD. |
| Asonitou & Koutsouki (2016) | DCD (54) TD (54) General population |
36 (66.7%) 36 (66.7%) |
Total of 42 5-year-olds and 66 6-year-olds: 5.5 (0.4) |
Exclusion of children with any other medical or neurological condition, or identified intellectual disability. |
Selective attention (visual) Planning |
CAS: Expressive Attention, Number Detection, Receptive Attention Matching Numbers, Planned Codes, Planned Connections |
A significant proportion of children with DCD were impaired on planning and attention measures (p < .01). Globally, children with DCD had more difficulties than TD children in all measured domains, and difficulties in planning were greater than those in attention. |
| Asonitou et al. (2012) | DCD (54) 5-year-old (24) 6-year-old (30) TD (54) 5-year-old (18) 6-year-old (36) General population |
36 (66.7%) 13 (54.2%) 23 (76.7%) 37 (68.5%) 15 (83.3%) 22 (61.1%) |
42 5-year-olds: 5.2 (0.3) 66 6-year-olds: 5.8 (0.2) |
Exclusion of children diagnosed with emotional or behavioral disorder, with a history of pre- or existing developmental disorder (such as ADHD), or with an intellectual disability (IQ < 70). |
Selective attention (visual) Planning |
CAS: Expressive Attention, Number Detection, Receptive Attention Matching Numbers, Planned Codes, Planned Connections |
Children with DCD performed more poorly than TD children on all tasks (p < .05), indicating difficulties in terms of both attention and planning when compared to healthy controls. Also, more severe motor impairment seems to be associated with poorer planning abilities. |
| Barray et al. (2008) | DD (32) AP (16) Learning disorders centers |
24 (75.0%) 6 (37.5%) |
9.1 (2.3) 9.0 (2.1) |
Exclusion of children with probable personality disorder, social conduct disorder, or verbal IQ < 80. |
Selective attention (visual) Selective attention (auditive) Planning Fluency (nonverbal) |
NEPSY: Visual Attention Auditory Attention and Response Set Tower task Design Fluency |
Children with DD performed significantly better than those with AP only on the Visual attention task (p = .022). All children had difficulties in the Design Fluency task that seemed to be the most difficult task for them. Performances on the other tasks were globally within the normative range. |
| Bernardi et al. (2017) | DCD (17) MD (17) TD (17) General population |
6 (35.3%) 8 (47.1%) 13 (76.5%) |
12.0 (1.2) 10.5 (0.6) 11.3 (1.0) |
Exclusion of children diagnosed with ADHD, ASD, reading, language and IQ < -2 SD, or any medical condition. | Working memory (verbal) Working memory (nonverbal) Fluency (verbal) Fluency (nonverbal) Response inhibition (verbal) Response inhibition (nonverbal) Planning (verbal) Planning (nonverbal) Flexibility (verbal) Flexibility (nonverbal) |
WMTBC: Listening Recall Odd-One-Out test D-KEFS: Verbal Fluency D-KEFS: Design Fluency Verbal VIMI (total errors) Motor VIMI (total errors) D-KEFS: Sorting test (verbal sorts) D-KEFS: Sorting test (nonverbal sorts) D-KEFS: Trail Making test CANTAB: Intra-/Extra-Dimensional Shift |
Children with DCD performed significantly more poorly than TD children on all nonverbal measures (p < .001) and on the verbal fluency task (p = .001) at both time points (2-year follow-up). Children with MD also had poorer performance on all nonverbal measures, except the flexibility one. At time 2, only nonverbal WM (p = .005) and nonverbal fluency (p = .047) differences remained between MD and TD groups. Improvement over time was significant for verbal (p < .001) and nonverbal (p = .002) WM, fluency and flexibility(p < .001), and for nonverbal planning (p = .013). It was not significant for verbal and nonverbal inhibition and verbal planning. Changes over time were similar between each group. |
| Bernardi et al. (2016) | DCD (23) MD (30) TD (38) (Same sample as Leonard et al., 2015) General population |
16 (69.6%) 17 (56.7%) 17 (44.7%) |
10.0 (1.1) 8.9 (1.2) 9.3 (1.0) |
Exclusion of children diagnosed with any other neurodevelopment-tal disorder, including ADHD. | Response inhibition (verbal) Response inhibition (nonverbal) |
Verbal VIMI (total errors and total completion time) Motor VIMI (total errors and total completion time) |
On the motor inhibition task, children with DCD or MD had difficulties performing accurately. On the verbal inhibition task, they took significantly more time than TD children (p = .002), but the accuracy between groups was similar. Inhibition impairments in DCD and MD groups thus appear to affect accuracy when a motor response is required and completion time when the response is given verbally. There were no significant differences between DCD and MD groups. |
| Biotteau et al. (2017) | DCD (22) DCD+ DDL (23) DDL (20) Referred by a learning disability center or health care profession-nals |
16 (72.7%) 16 (69.6%) 12 (60.0%) |
9.7 (1.6) 9.9 (1.2) 10.2 (1.3) |
Exclusion of children with intellectual disability, SLI or ADHD, according to DSM-IV-TR criteria. Presence of DDL, excluding surface dyslexia, in DCD+DDL group. |
Sustained attention (visual) Response inhibition (nonverbal) Working memory (verbal) |
CPT-II (omission errors) CPT-II (commission errors) WISC-IV: Digit Span and Letter-Number Sequencing |
All children had mean scores within or slightly above the normal range on the CPT-II. Variations between groups were not significant. WM index was within the normal range in the three groups. Having a dual diagnosis did not lead to a cumulative impact on cognitive abilities. |
| Blais et al. (2017) | DCD (10) TD (10) Hospital |
7 (70.0%) 3 (30.0%) |
13.5 (1.4) 13.5 (1.8) |
Exclusion of children with a history of head trauma or epilepsy, an intellectual disability or ADHD according to DSM-5 criteria. | Sustained attention (visual) Response inhibition (nonverbal) |
CPT-II (omission errors) CPT-II (commission errors) |
Children with DCD performed significantly worse than TD children. Their average percentages of commission, omission and perseveration errors were significantly greater than those of control individuals (p < .05). There was no difference between groups for reaction times. |
| Chen et al. (2012) | SDCD (20) MDCD (46) TD (36) Research database |
9 (45.0%) 16 (34.8%) 24 (66.7%) |
9.5 (0.3) 9.6 (0.3) 9.7 (0.3) |
Exclusion of children with any signs of neurolo-gical of physical impairments, developmental disorders or intellectual disability, accor-ding to a rehabi-litation physician. | Attentional inhibition (endogenous mode of orienting attention) | COVAT | The capacity of children with DCD, both severe and moderate, to intentionally disengage their attention from invalid cued location when the delay between precue and target stimulus was longer was reduced. This suggests a deficit of attentional control in DCD, more specific to the endogenous mode of orienting attention and referring to the process of disengagement inhibition. |
| de Castelnau et al. (2007) | DCD (24) TD (60) Hospital |
18 (75.0%) 30 (50.0%) |
3 age groups: 8–9 years, 10–11 years and 12–13 years. 8 children with DCD and 20 TD children in each of them. |
Exclusion of children with ADHD, according to a brief neuropsychological examination and DSM-IV criteria, and with an IQ < 80. | Sustained attention (visual) Response inhibition (nonverbal) |
CPT double version (correct responses) CPT double version (commission errors) |
Children with DCD had significantly less correct responses than TD children (p < .0001), but it increased with age (p < .05). They omitted significantly more responses than controls. However, there was no significant difference in number of commission errors between groups, and these decreased with age. In conclusion, children with DCD had poorer attentional capacities than TD children, but they were not more impulsive, and their capacities improved with age. |
| Dyck & Piek (2010) | DCD (20) RELD (21) PLA (22) PMC (28) Referred by health care profession-nals |
13 (65.0%) 16 (76.2%) 14 (63.6%) 17 (60.7%) |
8.4 (2.1) 7.1 (1.8) 7.5 (1.6) 8.8 (3.1) |
Exclusion of children diagnosed with any other comorbid disorders. | Response inhibition (nonverbal) Working memory (verbal) |
Go/No Go task (commission errors) Trailmaking/Me-mory Updating task, Goal Neglect task |
Children with DCD had scores within the normal range on the response inhibition task. Their performances were within the low normal range for WM tasks. Differences with children with PMC were not significant. Scores of children in the RELD group were lower on the response inhibition and WM tasks (p < .05), indicating greater difficulties in this group. |
| Gonzalez et al. (2016) | DCD (10) TD (12) Specialized clinic |
7 (70.0%) 8 (66.7%) |
10.1 (1.0) 10.0 (1.1) |
Exclusion of children diagnosed with ADHD. | Attentional inhibition (exogenous mode of orienting attention) | Visuospatial attention task cued and non-cued conditions | Children with DCD made more inhibition errors (saccades to the cue) than TD children (p = .002), indicating poor inhibitory control. These inhibition difficulties resulted in inappropriate allocation of visual attention. |
| Kaiser & Albaret (2016) | DCD (7) ADHD (9) TD (15) Specialized school, referred by health care profession-nals |
Not mentioned | 9.9 (0.9) 10.2 (1.3) 9.6 (1.3) |
Exclusion of children with a dual diagnosis of DCD and ADHD, and with an IQ < 70. | Selective attention (visual) Alertness (visual) Divided attention |
KITAP: Distractibility Alerting Divided Attention |
Results of children with DCD on KITAP tasks were not significantly different from results of children with ADHD or of TD children. Thus, the three groups cannot be discriminated based on their performance on the KITAP. |
| Kirby et al. (2010) | DCD (11) TD (28) Research database |
8 (72.7%) 13 (46.4%) |
9.9 10.2 (SDs not available) |
Exclusion of children with severe learning difficulties or low cognitive ability, according to teachers. Inclusion of children with ADHD symptoms. |
Planning | River Crossing task | Significant differences between groups were seen in children’s planning strategies. Children with DCD tended to add mats (p < .05), but not modify their placement of mats, whereas TD children were more likely to change spacing of mats. This suggests that initial mat placement plan of TD children was more effective than that of children with DCD. This indicates that children with DCD may have difficulty to elaborate a plan as efficiently as TD children and may also not know how to improve it. |
| Leonard et al. (2015) | DCD (23) MD (30) TD (38) (Same sample as Bernardi et al., 2016) General population |
16 (69.6%) 17 (56.7%) 17 (44.7%) |
10.0 (1.1) 8.9 (1.2) 9.3 (1.0) |
Exclusion of children diagnosed with ASD or ADHD, and of children with IQ, language or reading skills more than two SD below the mean. | Working memory (verbal) Working memory (nonverbal) Fluency (verbal) Fluency (nonverbal) Response inhibition (verbal) Response inhibition (nonverbal) Planning (verbal) Planning (nonverbal) Flexibility (verbal) Flexibility (nonverbal) |
WMTBC: Listening Recall Odd-One-Out test D-KEFS: Verbal Fluency D-KEFS: Design Fluency Verbal VIMI (total errors) Motor VIMI (total errors) D-KEFS: Sorting test (verbal sorts) D-KEFS: Sorting test (nonverbal sorts) D-KEFS: Trail Making test CANTAB: Intra-/Extra-Dimensional Shift |
For nonverbal WM, fluency and inhibition tasks, children with MD or DCD scored significantly lower than TD children (p < .001). For nonverbal planning, only the MD group (not the DCD group) differed significantly from the TD group (p < .001). There were no significant differences between groups on flexibility tasks or on any of the verbal measures. In summary, children with DCD or MD had more difficulties on nonverbal tasks compared to TD children. |
| Mandich et al. (2002) | DCD younger + older (20) TD younger + older (20) Specialized clinic |
Not mentioned | Younger: 8.6 (0.8) Older: 10.6 (0.7) Younger: 8.5 (0.7) Older: 10.8 (0.8) |
Exclusion of children diagnosed with ADD. | Response inhibition (nonverbal) Attentional inhibition (exogenous mode of orienting attention) |
Visual Simon task (failure-to-inhibit errors) Visual Simon task (reaction times) |
Children with DCD seem to have no deficit regarding the time needed to suppress an incorrect response and this ability appears to develop at the same rate in both groups. However, children with DCD had a reliably smaller rate of correct responses in the incompatible trials compared to TD children (p = .011). Overall, children with DCD exhibited an inhibitory dysfunction regarding manual response inhibition, manifesting itself in terms of error rate. |
| Mandich et al. (2003) | DCD (18) TD (18) Specialized clinic |
Not mentioned | 9.9 (1.5) 9.8 (1.4) |
No mention of exclusion. | Response inhibition (nonverbal) Attentional inhibition (endogenous mode of orienting attention) |
Go/No Go task with both informative and uninformative precue conditions (anticipation and failure-to-inhibit errors) Go/No Go task with both informative and uninformative precue conditions (reaction times) |
Children with DCD did not commit more anticipation errors than TD children, but they produced about twice as many failure-to-inhibit errors (p = .007). Children with DCD may have impaired inhibitory control, since they needed more time to intentionally disengage their attention from the cued position (disengagement inhibition). They also exhibited difficulty to inhibit the unwanted movement of attention urged by precues. Thus, they exhibited more difficulties than controls in restraining both their manual and attentional movements. |
| Piek et al. (2007) | DCD (18) ADHD-I (20) ADHD-C (19) TD (138) Referred by health care profession-nals |
12 (66.7%) 16 (80.0%) 15 (78.9%) 59 (42.8%) |
8.8 (2.0) 10.8 (1.8) 10.7 (2.3) 10.3 (2.2) |
Exclusion of children with an estimated IQ < 80. | Working memory (verbal) Flexibility |
Trailmaking/Memory Updating task, Goal Neglect task Visual Inspection Time task |
On the Goal Neglect task, children with DCD made more errors than the three other groups (p < .05). On the Trailma-king/Memory Updating task, children in the DCD group were significantly slower than those in other groups (p < .01) but did not commit more errors. They were also slower than the other groups on the set-shifting task. Thus, performance of children with DCD was significantly poorer than that of ADHD and TD children on all measures of EF, and there was no significant difference between ADHD and TD children. |
| Pratt et al. (2014) | DCD (26) TD (24) General population |
22 (84.6%) 13 (54.2%) |
9.9 (2.5) 9.6 (2.0) |
Exclusion of children with any other disorder, such as ADHD, ASD or dyslexia. | Planning (reduced motor-load) Planning (high motor-load) Response inhibition (reduced motor-load/verbal) Response inhibition (high motor-load/nonverbal) |
NEPSY: Tower task Rotational Bar task Stroop task NEPSY: Knock-Tap task |
Children with DCD performed significantly more poorly than TD children on both the high motor-load and reduced motor-load planning tasks. They also had significantly lower scores than TD children on the reduced motor-load inhibition task, but differences in performance on the high motor-load inhibition task were not significant. Results might have been influenced by the tasks’ complexity. |
| Querne et al. (2008) | DCD (9) TD (10) Hospital |
7 (77.8%) 7 (70.0%) |
9.9 (1.8) 10.0 (1.1) |
Exclusion of children with a history of neurological or psychiatric disorders. | Sustained attention (visual) Response inhibition (nonverbal) |
Go/No Go task (omission errors) Go/No Go task (commission errors) |
Children with DCD did not make more commission errors than TD children, but they made significantly more omission errors (p = .011). Thus, children with DCD seem to be as effective as TD children in inhibiting a prepotent motor response, but to have more difficulties with sustained attention. |
| Rahimi-Golkhan-dan et al. (2016) | DCD (12) TD (24) Schools, general population |
4 (33.3%) 10 (41.7%) |
9.8 (1.4) 10.3 (1.6) |
Exclusion of children diagnosed with intellectual disability, or neurological or psychiatric disorders such as ADHD. | Sustained attention (visual) Response inhibition (nonverbal) |
Go/No Go task with positively- and negatively-valenced stimuli (omission errors) Go/No Go task with positively- and negatively-valenced stimuli (commission errors) |
Children with DCD were more impulsive than TD children with happy faces stimuli, as they made more commission errors (p = .017). The difference between groups for sad faces was not significant. There was no significant difference between the two groups for omission errors. Overall, results showed a deficit of inhibitory control in the DCD group when the no-go stimulus was a compelling, positively-valenced cue, which shows a deficit in ‘hot’ executive functions. |
| Ruddock et al. (2016) | DCD (62) 6 years (7) 7 (13) 8 (11) 9 (11) 10 (15) 11 (5) TD (109) 6 years (28) 7 (21) 8 (21) 9 (18) 10 (15) 11 (5) 12 (1) Schools, general population |
35 (56.5%) 3 (42.8%) 9 (69.2%) 9 (81.8%) 7 (63.6%) 6 (40.0%) 1 (20.0%) 48 (44.0%) 9 (32.1%) 7 (33.3%) 10 (47.6%) 12 (66.7%) 7 (46.7%) 2 (40.0%) 1 (100.0%) |
6.4 (0.6) 7.5 (0.3) 8.6 (0.4) 9.5 (0.3) 10.6 (0.3) 11.3 (0.2) 6.4 (0.4) 7.5 (0.3) 8.4 (0.3) 9.5 (0.3) 10.3 (0.3) 11.4 (0.2) 12.3 (0.0) |
Exclusion of children with a history of developmental (ASD, ADHD), physical and/or neurological condition reported in a parent/teacher pre-screening questionnaire. | Response inhibition (nonverbal) | Double-Jump Reaching task–Modified version | Until 10–11 years old, children with DCD performed slower and with more variability than TD children. Therefore, in general, they were less efficient than controls, but the developmental lag in their performance seemed to lessen in later childhood. Performance of both groups improved with age, but the growth curve was different. |
| Ruddock et al. (2015) | DCD (42) 6–7 years (10) 8–9 (16) 10–12 (16) TD (87) 6–7 years (26) 8–9 (38) 10–12 (23) Schools, general population |
22 (52.4%) 5 (50.0%) 11 (68.8%) 6 (37.5%) 34 (39.1%) 9 (34.6%) 15 (39.5%) 10 (43.5%) |
7.3 (0.7) 8.9 (0.6) 11.1 (0.4) 7.2 (0.5) 8.9 (0.6) 10.7 (0.5) |
Exclusion of children for whom any developmental, neurological and/or physical condition was reported, which was confirmed by the child’s school health officer. | Response inhibition (nonverbal) | Double-Jump Reaching task–Modified version | Children with DCD were generally slower than TD children (p = .002) and they made significantly more anticipation errors, indicating difficulties in inhibitory control. Moreover, only the differences between younger children and the two other groups were significant (p = .005); mid-aged and older children did not significantly differ in their anticipation error rate. Thereby, initiation inhibition capacities are poorer in children with DCD than in TD children, but the gap between them lessen when they get older. |
| Sartori et al. (2020) | DCD (63) MD (31) TD (63) Schools |
39 (62.0%) 20 (65.0%) 39 (62.0%) |
8.7 (0.64) 8.9 (0.74) 8.7 (0.63) |
Exclusion of children with a neurological condition or with ADHD. | Flexibility Response inhibition (nonverbal) Response inhibition (verbal) Working memory (verbal) Working memory (visuospatial) |
Five Digits Test, Trail Making Test Go/No Go app (motor response) Go/No Go app (verbal response) Hayling Test, Oral Word Span in Sentences Odd-One-Out |
DCD and MD children were slower on the Oral Word Span and the Odd-One-Out than TD children (p < .001). Children with DCD performed more poorly than TD children on both tasks (verbal and motor responses) of the Go/No Go app (p < .005) and on the Hayling test (p < .001). DCD children made more mistakes and had longer completion times on parts 2, 3 and 4 of the Five Digits Test (p < .001), and MD children made more mistakes than TD children on parts 3 and 4 of the Five Digit Test (p = .01). Children with DCD also performed more poorly than TD children on both parts of the Trail Making Test. No statistical differences were found between DCD and MD children. |
| Sumner, Pratt, & Hill (2016) | DCD (52) TD (52) General population |
36 (69.2%) 36 (69.2%) |
9.2 (2.2) 9.3 (1.5) |
Exclusion of children diagnosed with any other developmental disorder (ADHD, ASD, dyslexia), neurological condition, or other medical condition that could explain motor impairment. | Working memory (verbal) | WISC-IV: Digit Span, Letter-Number Sequencing | Scores of children with DCD were significantly lower than TD children on the WM index (p = .02). Children with DCD performed significantly worse than TD children on the Digit span task (p < .05), but not on the Letter-number sequencing task. Almost 30% of children with DCD had scores of more than 1 SD below the population mean on the Digit span. Thus, the results showed some indication of difficulties in WM. |
| Thornton et al. (2018) | DCD (9) DCD+ ADHD (18) ADHD (20) TD (20) Schools,advertising in hospitals and physicians’ offices |
6 (67.0%) 15 (83.0%) 18 (90.0%) 8 (40.0%) |
13.6 (2.74) 10.9 (2.62) 12.4 (2.8) 10.6 (1.67) |
Exclusion of children with a visual or intellectual impairment and a neurological or medical disorder. | Response inhibition (nonverbal) |
Go/No Go Task (commission errors) |
Children with co-occurring DCD and ADHD made more commission and total errors than TD children (p < .05). However, the reaction times and omission errors did not differ between groups. |
| Toussaint-Thorin et al. (2013) | DD (13) TD (14) Hospital |
11 (84.6%) 8 (57.1%) |
10.1 (1.4) 10.4 (1.3) |
Exclusion of children with possible associated dyslexia and with a verbal IQ < 70. Inclusion of children with ADHD. |
Selective attention (auditive) Flexibility Planning Response inhibition (nonverbal) Fluency (verbal) General executive functioning |
NEPSY: Auditory Attention and Response Set Trail Making test A and B for Children NEPSY: Tower task, BADS-C: 6-Part test The Paired Images test NEPSY: Verbal Fluency Ecological assessment: cooking task |
No deficits were found on measures of attention, flexibility and fluency. Almost half of children with DD had a score in the clinical range on the inhibition task. Three children with DD had a pathological score on the tower task, but planning appeared to be more impaired on the 6-Part test, the strategy score being particularly affected. Thus, children with DD exhibited deficits of nonverbal planning and inhibition (p < .05). On the cooking task, children with DD made significantly more errors than TD children (p < .001) and they were not able to inhibit their verbalizing behavior, despite the task’s guidelines. They were also significantly more dependent than TD children (p = .034), suggesting a limited capacity to find strategies or solutions to face a problem. |
| Tsai et al. (2012) | DCD (24) TD (30) General population |
12 (50.0%) 15 (50.0%) |
11.6 (0.3) 11.7 (0.4) |
Exclusion of children with ADHD according to DSM-IV criteria, with any known neurological disorder, behavioral problems, pervasive developmental disorders or special educational needs, or an IQ < 85 or > 115. | Alertness (visual) Working memory (visuospatial) |
Visuospatial Working Memory Paradigm (non-delay condition) Visuospatial Working Memory Paradigm (delay condition) |
Children with DCD performed less accurately than TD children in the conditions with delays (p < .001), but not in the non-delay condition. This indicates difficulty in WM tasks, but not in the attentional task. EEG results showed that children with DCD allocated fewer resources to compare spatial locations (p < .001). Overall, a deficit in retrieval of spatial information was found in children with DCD through EEG measures, which seemed to impair their WM performance. |
| Tsai et al. (2010) | DCD (30) TD (30) General population |
15 (50.0%) 15 (50.0%) |
9.5 (0.3) 9.6 (0.2) |
Exclusion of children with ADHD according to DSM-IV, any defi-nite signs of neuro-logical disorders, behavioral pro-blems or pervasive development disor-ders, special needs in education, or an IQ < 85 or > 125. | Attentional inhibition (exogenous mode of orienting attention) | Visuospatial attention (eye-gaze cueing) paradigm | There were no significant differences between groups on error rates. Children with DCD responded significantly slower than TD children in all conditions (p < .001). This suggests a reduced alertness to the imminent appearance of the target. Results showed a deficit in reflexive/automatic (exogenous) orienting of visual attention. |
| 1Tsai et al. (2009) | DCD (28) TD (26) General population |
12 (42.9%) 12 (46.2%) |
9.5 (0.3) 9.5 (0.3) |
Exclusion of children with ADHD according to DSM-IV, any defi-nite signs of neuro-logical disorders or behavioral problems, special needs in education, or an IQ < 85 or > 125. | Attentional inhibition (endogenous mode of orienting attention) | Endogenous Posner Paradigm | Children with DCD responded more slowly than TD children (p < .0001), but there was no significant difference on the error rate. They had more difficulties than TD controls to move their attention when it has been primed to a falsely indicated location. Thus, they exhibited an inhibition deficit in the endogenous mode of orienting attention. |
| 2Tsai et al. (2009) | DCD-LEs (36) TD (36) General population |
19 (52.8%) 19 (52.8%) |
9.9 (0.5) 9.8 (0.5) |
Exclusion of children with ADHD according to DSM-IV, special educational needs, physical or behavioral problems, or evident neurological damage. | Attentional inhibition (endogenous mode of orienting attention) Attentional inhibition (exogenous mode of orienting attention) |
COVAT Visual Simon task (reaction times) |
Children with DCD took longer than TD children to respond to neutral trials, indicating a reduced alertness to the imminent appearance of the target. Results showed a deficit in DCD children associated with only the intentional disengagement of attention (endogenous mode; p < .001) but not the automatic/reflexive dislocation of attention (exogenous mode). |
| Wang et al. (2015) | DCD (23) TD (23) General population |
12 (52.2%) 12 (52.2%) |
9.4 (0.5) 9.3 (0.5) |
Exclusion of children with ADHD according to DSM-IV criteria, with any definite signs of neurolo-gical disorders, behavioral problems or special educational needs, or an IQ < 85 or > 125. | Attentional inhibition (exogenous mode of orienting attention) | Visuospatial attention (eye-gaze cueing) paradigm | There were no significant differences between groups on error rates. Children with DCD responded significantly slower than TD children in all conditions (p < .001). They had a poorer general attentional orienting capacity and a difficulty to effectively alter a planned action after their attention had been incorrectly oriented. |
| Williams et al. (2013) | DCD (10) DCD+ ADHD (16) ADHD (14) TD (18) Schools, hospital or referred by health care professio-nals |
6 (60.0%) 14 (87.5%) 8 (57.1%) 10 (55.6%) |
8.5 (1.2) 9.1 (1.7) 10.1 (1.4) 10.2 (1.3) |
Exclusion of children with ADHD or DCD in other groups than the ones they are supposed to be in, with any physical or neurological condition that could contribute to motor impairment, or with an IQ < 70. | Sustained attention (auditive) | TEA-Ch: Score! | Children in the DCD+ADHD group had significantly more difficulty in the sustained attention task compared to the TD children. Scores in the DCD group were also lower than in the ADHD group, but the differences were not significant. There were no other differences between other groups. |
| Wilson & Maruff (1999) | DCD (20) TD (20) General population |
10 (50.0%) 10 (50.0%) |
10.3 10.6 |
Exclusion of children with current or history of neurological diseases, including head injury, psychiatric disorders, including ADHD, or an estimated IQ < 80. | Attentional inhibition (endogenous and exogenous modes of orienting attention) | COVAT | Within each group, responses were significantly faster for valid than invalid cues, but the effect was much greater for children with DCD (p < .001). Even when the delay between the cue and the target was longer, these children still had difficulty to shift their attention as efficiently as TD children. Results showed a deficit in the endogenous disengagement of attention in children with DCD, while the exogenous orienting mode was not affected. |
| Wilson et al. (1997) | DCD (20) TD (20) General population |
18 (90.0%) 18 (90.0%) |
9.8 9.7 |
Exclusion of children with current or past history of neurological diseases, including head injury, psychiatric disorders, including ADHD, or as estimated IQ < 80. | Attentional inhibition (endogenous and exogenous modes of orienting attention) | COVAT | Children with DCD responded slower than TD children (p = .001) and increasing delay between the cue and the stimulus did not help them as it did for TD children. They were able to complete attentional orienting as efficiently as TD children when the delay was brief. Reaction time was also significantly greater in the DCD group for invalid cues, compared with the TD group (p = .001). These results showed a deficit in the disengagement of attention in children with DCD. Thus, they have a deficit in the endogenous mode of orienting attention, but not in the exogenous mode. |
| Zhu et al. (2012) | DCD (39) TD (39) Hospital |
28 (71.8%) 28 (71.8%) |
8.1 (0.5) 8.0 (0.7) |
Exclusion of children with any comorbid neurological diseases, mental and neurodevelop-mental disorders, according to detailed physical and psychiatric examinations. | General executive functioning | Wisconsin Card Sorting Test | Children with DCD committed significantly more errors, perseverative responses and perseverative errors than TD children (p < .001). They also needed more trials to complete the first category (p < .001). Results indicated difficulties in executive functioning in children with DCD. |
Note: M = mean; SD = standard deviation; DCD = developmental coordination disorder; TD = typically developing; BVN-5-11 = Development Neurological Assessment Battery; AWMA = Automated Working Memory Assessment; WM = working memory; ADHD = attention-deficit/hyperactivity disorder (-I = impulsive; -C = combined); SLI = specific language impairment; ASD = autism spectrum disorder; AS = Asperger syndrome; IQ = intellectual quotient; MLD = mild learning difficulties; CAS = Das-Naglieri Cognitive Assessment System; DD = developmental dyspraxia; AP = dyspraxia following preterm birth; NEPSY = Developmental Neuropsychological Assessment; MD = motor difficulties (without DCD); WMTBC = Working Memory Test Battery for Children; D-KEFS = Delis-Kaplan Executive Function System; VIMI = Verbal Inhibition Motor Inhibition test; CANTAB = Cambridge Neuropsychological Test Automated Battery; DDL = developmental dyslexia; CPT-II = Continuous Performance Test, Second Edition; WISC-IV = Wechsler Intelligence Scale for Children, Fourth Edition; SDCD = severe developmental coordination disorder; MDCD = moderate developmental coordination disorder; COVAT = Covert Orienting of Visuospatial Attention Task; RELD = mixed receptive expressive language disorder; PLA = relatively poor language ability; PMC = relatively poor motor coordination; KITAP = computerized test battery of attention for children; MAND = McCarron Assessment of Neuromuscular Development; BADS-C = Behavioural Assessment of the Dysexecutive Syndrome in Children; BOT-2-SF = Short Form Bruininks-Oseretsky Test of Motor Proficiency, second edition; DCD-LEs = DCD on lower extremities; TEA-Ch = Test of Everyday Attention for Children.