TABLE 2.
Comparison of the cognitive and auditory profiles for control vs. dyslexic subjects, and for dyslexic subjects from the D+ (normal pitch contour identification) vs. D- (deficit in pitch contour identification) groups; Correlation of pitch identification scores with measures of cognitive function and temporal auditory processing
| Comparison of the cognitive and auditory profiles | Correlation with pitch identification scores | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Measure | Controls | Dyslexics | C/D | Dyslexics D+ | Dyslexics D− | D+/D− | Controls | Dyslexics | ||||||
| p value | p value | p value | ρ | p value | ρ | |||||||||
| Reading and spelling accuracy | ||||||||||||||
| Reading real words (words per minute) | 97.9 | (10.5) | 63.9 | (10.6) | <0.0001 | 64.1 | (10.8) | 63.6 | (10.5) | 0.9089 | 0.6154 | (−0.0939) | 0.2776 | (−0.2013) |
| Reading nonwords (words per minute) | 61.8 | (10.0) | 31.8 | (5.8) | <0.0001 | 32.4 | (5.3) | 30.4 | (7.0) | 0.4103 | 0.4889 | (0.1291) | 0.4686 | (0.1351) |
| Spelling real words (correct words) | 25.0 | (2.1)a | 16.9 | (3.7) | <0.0001 | 16.5 | (3.8)a | 18.0 | (3.2) | 0.2916 | 0.5760 | (0.1045) | 0.2803 | (−0.2002) |
| Rapid automatized naming (RAN) | ||||||||||||||
| RAN colors (s) | 26.2 | (3.4) | 32.7 | (6.3) | <0.0001 | 31.0 | (3.9) | 37.0 | (8.8) | 0.0126 | 0.5531 | (−0.1107) | 0.8107 | (−0.0448) |
| RAN objects (s) | 29.5 | (2.9) | 36.2 | (5.6) | <0.0001 | 35.6 | (5.6) | 37.8 | (5.6) | 0.3235 | 0.7422 | (0.0616) | 0.4021 | (−0.1560) |
| RAN digits (s) | 18.3 | (3.1)a | 24.7 | (5.1) | <0.0001 | 23.1 | (4.3) | 28.7 | (4.7) | 0.0035 | 0.5250 | (−0.1186) | 0.1232 | (−0.2828) |
| RAN letters (s) | 17.1 | (2.8) | 25.1 | (5.8) | <0.0001 | 23.4 | (5.1) | 29.2 | (5.6) | 0.0087 | 0.1842 | (−0.2449) | 0.2289 | (−0.2225) |
| Mean RAN reaction time (s) | 22.8 | (2.5) | 29.7 | (4.7) | <0.0001 | 28.3 | (3.8) | 33.2 | (4.9) | 0.0059 | 0.4932 | (−0.1278) | 0.2542 | (−0.2111) |
| Phonemic awareness | ||||||||||||||
| Phoneme deletion (% correct) | 89.8 | (9.0)a | 81.9 | (10.9) | 0.0024 | 83.7 | (8.7) | 77.6 | (14.7) | 0.1578 | 0.8770 | (0.0290) | 0.9112 | (0.0209) |
| Spoonerisms (% correct) | 82.4 | (10.4) | 69.8 | (14.9)a | 0.0006 | 83.1 | (10.8) | 80.7 | (9.8) | 0.5713 | 0.3297 | (0.1811) | 0.2762 | (0.2018) |
| Working memory | ||||||||||||||
| Digit span (correct items) | 14.3 | (2.3) | 11.6 | (2.0) | <0.0001 | 11.6 | (2.0) | 11.6 | (2.0) | 0.9205 | 0.5171 | (0.1209) | 0.5463 | (0.1126) |
| Nonword repetition (correct items) | 25.6 | (4.8)a | 20.8 | (4.8) | 0.0004 | 21.9 | (4.8) | 18.3 | (3.9) | 0.0608 | 0.0138 | (0.4376) | 0.2285 | (0.2227) |
| Intellectual functioning | ||||||||||||||
| IQ score (Wechsler 1999) | 106.3 | (9.6)a | 107.8 | (12.6) | 0.6034 | 110.5 | (12.3) | 101.2 | (11.4) | 0.0636 | 0.1637 | (0.2565) | 0.2069 | (0.2331) |
| Psychoacoustic performance | ||||||||||||||
| Tone-in-noise detection (dB) | −9.4 | (1.5) | −9.4 | (1.6) | 0.8848 | −9.5 | (1.6) | −9.2 | (1.6) | 0.6946 | 0.8221 | (0.0421) | 0.6134 | (−0.0944) |
| Temporal auditory processing | ||||||||||||||
| FM detection, 2 Hz (Hz) | 4.7 | (1.9)a | 5.1 | (2.3)a | 0.5435 | 4.9 | (2.3) | 5.4 | (2.5) | 0.6332 | 0.6196 | (−0.0928) | 0.7621 | (−0.0567) |
| Frequency JND, 490 Hz (%) | 1.6 | (1.7)a | 1.9 | (1.5)a | 0.3272 | 1.2 | (0.9)a | 3.8 | (1.6) | 0.0001 | 0.0521 | (−0.3521) | 0.0001 | (−0.6379) |
For each measure in the comparison of the cognitive and auditory profiles, the mean and standard deviation (in brackets) for both groups are given, as well as a p value resulting from a two-sample t test (paired for C/D, unpaired for D+/D−). Normality of the data was verified using a Shapiro–Wilk test. When normality was rejected at a 5% significance level for at least one of the groups, a nonparametric Wilcoxon signed-rank test was used instead of a t test. For each measure in the correlation of pitch identification scores with measures of cognitive function and temporal auditory processing, Spearman’s ρ and the corresponding p value are given for each group. Total pitch identification scores with all stimulus configurations were used. For additional details about the auditory measures, see Appendix 1
aNormality was rejected at a 5% significance level