ERP Correlates of Proactive and Reactive Cognitive Control in Treatment-Naïve Adult ADHD

Abstract

This study investigated whether treatment naïve adults with Attention Deficit Hyperactivity Disorder (ADHD; n = 33; 19 female) differed from healthy controls (n = 31; 17 female) in behavioral performance, event-related potential (ERP) indices of preparatory attention (CueP3 and late CNV), and reactive response control (Go P3, NoGo N2, and NoGo P3) derived from a visual cued Go/NoGo task. On several critical measures, Cue P3, late CNV, and NoGo N2, there were no significant differences between the groups. This indicated normal preparatory processes and conflict monitoring in ADHD patients. However, the patients had attenuated Go P3 and NoGoP3 amplitudes relative to controls, suggesting reduced allocation of attentional resources to processes involved in response control. The patients also had a higher rate of Go signal omission errors, but no other performance decrements compared with controls. Reduced Go P3 and NoGo P3 amplitudes were associated with poorer task performance, particularly in the ADHD group. Notably, the ERPs were not associated with self-reported mood or anxiety. The results provide electrophysiological evidence for reduced effortful engagement of attentional resources to both Go and NoGo signals when reactive response control is needed. The absence of group differences in ERP components indexing proactive control points to impairments in specific aspects of cognitive processes in an untreated adult ADHD cohort. The associations between ERPs and task performance provided additional support for the altered electrophysiological responses.

Fig 1. The cued Go/NoGo task.

Left: The task was to respond to S2 in all animal-animal pairs (A-A) and withhold responses to S2 in all animal-plant pairs (A-P) and Irrelevant pairs (P-P, P-H). Each trial had a total duration of 3000 ms, where the first S1 and S2 had their onsets at 300 ms and 1400 ms into the trials, respectively. Duration of stimulus presentation was 100 ms. Right: Shows the size of the stimuli relative to the 17-inch computer screen.

Fig 2. Grand average ERP waves over frontal, central, and parietal electrodes for the ADHD and the healthy control participants in Relevant (Animal = S1) and Irrelevant (Plant = S1) conditions in the cued Go/NoGo task.

The vertical dotted lines indicate the duration of S1 and S2. The grey areas indicate the time intervals that the amplitudes of the Cue P3 (mean of the 300–550 ms interval after onset of S1) and the late CNV (mean of the last 100 ms before onset of S2) were extracted from. They are marked at the electrodes where the components had their maximum amplitudes. Topographic maps of the grand average maximum amplitudes at Cz for late CNV and Pz for Cue P3 are also shown.

Fig 3. Grand average ERP waves over frontal, central, and parietal electrodes for the ADHD and the healthy control groups after S2 in Go (A—A) and NoGo (A—P) conditions in the cued Go/NoGo task.

The grey areas indicate the time intervals that the mean amplitudes of the Go P3 (280–380 ms), the NoGo N2 (200–300 ms), and the NoGo P3 (300–480 ms) waves were extracted from after onset of S2. The grey areas are marked at the electrodes where the components are most clearly observed. Topographic maps of the grand average peak amplitudes at Cz for Go P3 and NoGo P3 are also shown.