Flanker task performance
| Measure, mean ± SD | Controls (n = 34) | ADHD (n = 34) | Test statistic with effect size (group comparison) |
|---|---|---|---|
| Mean RT, ms | 504.74 ± 90.13 | 532.32 ± 87.62 | Z = 1.41, NS; d = 0.31 |
| RT post-correct, ms | 509.59 ± 97.17 | 532.85 ± 91.92 | t66 = 1.01, NS; d = 0.25 |
| RT post-error, ms | 531.18 ± 90.61 | 576.79 ± 111.06 | t66 = 1.86, p < 0.1; d = 0.45 |
| SD-RT, ms | 110.97 ± 26.26 | 127.44 ± 29.50 | Z = 2.49, p < 0.05; d = 0.59 |
| SD-RT post-correct, ms | 107.71 ± 23.94 | 124.88 ± 29.83 | Z = 2.58; p < 0.01; d = 0.63 |
| SD-RT post-error, ms | 119.09 ± 50.29 | 130.38 ± 44.84 | Z = 0.80, NS; d = 0.24 |
| Total errors, no. | 40.56 ± 23.36 | 53.00 ± 28.67 | Z = 1.77, p < 0.1; d = 0.48 |
| Errors post-correct, no. | 24.06 ± 15.45 | 31.12 ± 16.58 | Z = 1.85, p < 0.1; d = 0.44 |
| Errors post-error, no. | 5.29 ± 5.20 | 8.97 ± 9.01 | Z = 1.60, NS; d = 0.50 |
| PES(traditional), ms | 21.59 ± 58.53 | 43.94 ± 61.64 | t66 = 1.53, NS; d = 0.37 |
| PES(robust), ms | 28.97 ± 29.91 | 44.74 ± 43.64 | t66 = 1.74, p < 0.1; d = 0.42 |
ADHD = attention-deficit/hyperactivity disorder; NS = not significant; PES(robust) = more robust measure of post-error slowing (mean RTs on individually paired post-error trials [E + 1] – pre-error trials [E − 1]; see methods section); PES(traditional) = traditional measure of post-error slowing (mean RTs after incorrect responses – mean RTs after correct responses); RT = reaction time to Go stimuli (only correct responses included); SD = standard deviation; SD-RT = standard deviation of reaction times to Go stimuli (only correct responses included).