Table 2 Cognitive performance of the PKU group (English and Italian PKU participants; N = 56). Z scores calculated from respective control groups (N = 30 and N = 19). To facilitate interpretation, for all scores, higher Z-score reflect worse performance. Scores in bold are significantly higher than expected. ms. = milliseconds; sec. = seconds
| Â | PKU Overall Z score | ||
|---|---|---|---|
Mean | SD | Diff from controls (t-test) | |
IQ | 0.8 | 1.3 | p < .001 |
Visual attention RTs | |||
 Simple Detection - ms. | 0.3 | 1 | n.s. |
 Detention with Distractors – ms. | 0.8 | 1.6 | p < .01 |
 Feature Search – ms. | 1.5 | 2.3 | p < .001 |
 Conjunction Search m. | 1.2 | 1.7 | p < .001 |
Visual attention accuracy | |||
 Detention with Distractors - % errors | 0.2 | 1 | n.s. |
 Feature Search - % errors | 0.2 | 2.6 | n.s |
 Conjunction Search - % errors | −0.1 | 0.8 | n.s |
Visuo-motor coordination | |||
 Pegboard (sec.) | 0.9 | 1.9 | p < .01 |
 Digit Symbol (%errors in 90 s.) | 0.7 | 1.2 | p < .01 |
 Trail-Making Test A: (sec.) | 0.8 | 1.9 | p < .01 |
Executive functions | |||
  WCST | |||
 Total errors | 0.4 | 1.6 | n.s. |
 Perseverative responses | 0.1 | 1.1 | n.s. |
 N of Completed Categories | 0.5 | 1.9 | p = .06 |
Trail-Making Tests | |||
 B (sec.) | 0.6 | 1.5 | p = .01 |
 B-A (sec.) | 0.5 | 1.7 | p = .06 |
Verbal Fluency | |||
 Letter (correct answers) | 0.6 | 1 | p < .01 |
 Semantic (correct answers) | 0.8 | 1.3 | p < .001 |
Short term memory | |||
 Digit span | 0.3 | 1.1 | n.s. |
 Corsi Block span | 0.0 | 1.1 | n.s. |
Sustained attention | |||
 RVP (% of errors) | 0.7 | 1.3 | p < .01 |
Learning | |||
Rey Auditory Verbal Learning Test | |||
 Trial A1-A5 (% errors) | 0.2 | 1.2 | n.s. |
 Retention (% errors A6) | 0.3 | 1.4 | n.s. |
 Delayed Recall (% errors) | 0.3 | 1.3 | n.s. |
Paired Associate Visual learning | |||
 (% errors) | 0.7 | 1.9 | p = .02 |
Overall (excluding IQ) | |||
 Mean | 0.5 | 0.8 | p < .001 |