Wild-Wall, N., Oades, R. D., Schmidt-Wessels, M., Christiansen, H., & Falkenstein, M. Neural activity associated with executive functions in adolescents with attention-deficit/hyperactivity disorder (ADHD). International Journal of Psychophysiology, 74, 19-27. doi:10.1016/j.ijpsycho.2009.06.003 [Request a copy] - View Article

The study was initially presented to 17th German EEG/EP Mapping Meeting, Giessen, Oct 31 - Nov 2, 2008

[Wild-Wall, N., Oades, R. D., Schmidt-Wessels, M., Christiansen, H., & Falkenstein, M. Neural correlates of executive functions in Attention-Deficit/ Hyperactivity Disorder (ADHD). 2009 Human Cognitive Neurophysiology, 2, 3. ] The essential results presented were as follows

Introduction: To assess changes of different executive functions & their neural (ERP) correlates in children with ADHD & their unaffected siblings with respect to healthy control children.

Methods: Specifically, we studied the processing of irrelevant stimuli, the control over inappropriate responses, and the detection of errors. A group of 15 children with ADHD (DSM-IV diagnosis from the PACS interview), 12 of their siblings and 12 independent typically developing children (mean age range 13-14 years) were presented with a flanker task with a Go/no-go condition. ERPs were topographically recorded and analysed from the midline.

1 - The behavioral data showed no significant differences on a comparison of the three groups. [Post-error correct response times (RTs) were increased in each group. ADHD and sibling groups showed twice the number of errors shown by controls on both congruent & incongruent arrows. The ADHD group alone showed more errors on the no-go trials than either siblings or controls.]

2 - Significant differences on stimulus-related ERPs: - First, the post-flanker ERPs mainly showed an attenuation of flanker processing in the ADHD group - an attenuated P1. Second, the later processing of the arrow-head was impaired with reduced amplitudes for the N2 and P3a components in ADHD.

3 - The post-response ERPs showed a general enhancement of the post-response negativity in the siblings. In particular there was no significant attenuation of error processing, as reflected in Ne/ERN & Pe, on the ADHD vs. the healthy control group comparisons.....[ but comparing the ADHD group vs. Siblings + Controls showed that the Ne was reduced (FCz) & the Pe was increased (Cz at c. 200 ms)].

4 - Finally, preparatory processes (CNV like negativity) were attenuated in siblings and more so in the patients.

Discussion: The pattern of results reveals a) specific changes of various cognitive control processes in ADHD which are not reflected in overt behaviour. b) The larger post-response potentials in the unaffected siblings may reflect compensatory enhancement of response monitoring. c) The study shows that ERPs have an additive value for assessing subtle cognitive changes in ADHD. The italicised results above are an elaboration from the text of the description in the abstract.

Supported in part by the NIH