Table 2.
N-back task performance for ADHD and control subjects.
| ADHD | HC | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Pre-MPH vs. post-MPH | Pre-MPH | Pre-MPH vs. HC | Post-MPH | Post-MPH vs. HC | ||||||||
| t | p | Mean | SD | t | p | Mean | SD | t | p | Mean | SD | |
| 1-back | ||||||||||||
| RT (ms) | 3.15 | 0.005** | 677.63 | 146.68 | −1.159 | 0.255 | 602.83 | 119.84 | 0.118 | 0.907 | 609.18 | 189.61 |
| RT variability (SD/mean) | 1.26 | 0.221 | 0.31 | 0.14 | −0.525 | 0.603 | 0.26 | 0.13 | 0.419 | 0.597 | 0.28 | 0.11 |
| Accuracy (correct %) | −1.691 | 0.106 | 92.35 | 13.22 | −0.05 | 0.961 | 95.07 | 9.32 | −0.827 | 0.415 | 92.13 | 10.68 |
| 2-back | ||||||||||||
| RT (ms) | 2.58 | 0.018* | 792.14 | 160.09 | −1.512 | 0.141 | 695.66 | 149.26 | 0.281 | 0.78 | 710.16 | 128.98 |
| RT variability (SD/mean) | 3.005 | 0.007** | 0.46 | 0.16 | −1.271 | 0.213 | 0.34 | 0.11 | 1.375 | 0.179 | 0.39 | 0.1 |
| Accuracy (correct %) | −3.158 | 0.005** | 82.33 | 12.2 | 0.869 | 0.391 | 87.59 | 12.18 | −0.362 | 0.72 | 86.05 | 11.09 |
RT and accuracy are presented for each condition. For ADHD subjects, data for pre-, post-MPH, and pre-MPH minus post-MPH are presented. T-values, p-values, and statistical significance in pre- and post-MPH columns are the results of Student's t-test between HC and each ADHD condition. Those in the pre- vs. post-MPH column are the results of a paired t-test. ADHD, attention deficit hyperactivity disorder; HC, healthy control; MPH, methylphenidate; SD, standard deviation; RT, reaction time.
*
p < 0.05,
**
p < 0.01.