Table 4.
Brain activation amplitude differences between the ADHD-REW/EF taxometrically- determined subgroup and non-ADHD. The table lists Montreal Neurological Institute stereotactic space coordinates of peak study group difference for each cluster that was found to be significant in two-sample t test (p<.001 corrected for searching the whole brain). Results are reported for motor inhibition and error processing on the Go/NoGo task and reward prospect and reward anticipation for the Monetary Incentive Delay task. For each brain region, the Cohen’s d effect size is depicted using sparkline graph to facilitate comparison of ADHD subgroup differences with non-ADHD. The final columns report omnibus F significance p levels from a secondary ANOVA comparing the ADHD subgroups. Subgroup ANOVA-identified regions that survive False Discovery Rate corrections for multiple comparisons are denoted with †.
| Max Peak x, y, z |
t | Effect Size Pattern* | ADHD Subgroup ANOVA | ADHD Subgroup Activation Level Pairwise | |
|---|---|---|---|---|---|
| Error Processing ADHD-EF/REW > HC | |||||
| Right precentral gyrus (BA 3b/4p) | 45, −16, 56 | 3.93 |
|
.025 | REW/EF > EF |
| Left middle frontal gyrus | −33, 5, 38 | 4.61 |
|
.016 | REW/EF > EF, NONE |
| Right superior frontal gyrus (Fp1) | 24, 35, 14 | 4.22 |
|
.173 | - |
| Left inferior frontal gyrus (pars opercularis BA 44) | −54, 8, 17 | 3.97 |
|
.071 | - |
| Right inferior frontal gyrus (pars opercularis BA 44/45) | 51, 11, 23 | 3.64 |
|
.008 † | REW/EF > EF, NONE |
| Right Rolandic operculum (OP3/BA 44) | 39, −10, 23 | 4.07 |
|
.003 † | REW/EF > EF, NONE |
| Right inferior frontal gyrus (pars triangularis BA 45) | 45, 35, 11 | 3.66 |
|
.101 | - |
| Left hippocampus/amygdala | −27, −19, −13 | 3.65 |
|
.117 | - |
| Left caudate | −15, 11, 20 | 3.77 |
|
.003 † | REW/EF > EF, NONE |
| Reward Prospect HC > ADHD-EF/REW | |||||
| Left inferior parietal lobule | −39, −37, 35 | 3.38 |
|
.027 | REW/EF > NONE |
| Effort to Obtain Reward ADHD-EF/REW > HC | |||||
| Right insula (Ig2/Ig1/TE1/OP3) | 39, −22, 11 | 4.18 |
|
0.078 | - |
| Left amygdala/hippocampus | −21, −10, −16 | 3.93 |
|
0.074 | - |
| Right amgydala | 24, −1, −7 | 3.37 |
|
0.047 | REW/EF > EF, NONE |
| Right putamen | 24, 14, −4 | 3.59 |
|
0.008 † | REW/EF > EF, NONE |
For sparkline graphs, the initial grey datapoint represents the Cohen’s d effect size from a supplemental two-sample t test that compared non-ADHD to all of the ADHD participants. Afterwards, subgroups ADHD-EF, ADHD-EF/REW, and ADHD-NONE are depicted (left-to-right). All sparkline values on this table are scaled relative to the maximum Cohen’s d=1.05 found across all four fMRI task conditions for the ADHD-EF/REW subgroup.