Neural Correlates of Proactive and Reactive Control Investigated Using a Novel Precued Antisaccade Paradigm.

Abstract

This ERP study investigated the neural correlates of proactive and reactive control using a novel precued antisaccade paradigm. Proactive control refers to preparatory processes during anticipation of a behaviorally relevant event; reactive control is activated after such an event to ensure goal attainment. A 64-channel EEG was obtained in 35 healthy subjects; video-based eye tracking was applied for ocular recording. In the task, a target (probe) appeared left or right of the fixation point 1800 ms after a central cue; subjects had to look toward the probe (prosaccade) or its mirror image position (antisaccade). Probes were positive, negative or neutral face expressions, with their frame colors instructing task requirements. The cue informed about antisaccade probability (70% vs. 30%) in each trial. High antisaccade probability was associated with larger CNV amplitude than low antisaccade probability. In trials with incongruence between expected and actual task requirements, probe N2 and P3a amplitudes were larger than in congruent trials. In incongruent trials, P3a was smaller for negative than positive and neutral probes. Task accuracy and speed were lower in incongruent trials and varied according to affective probe valence. EEG source imaging suggested the origin of the ERPs to be in orbitofrontal cortex and superior frontal gyrus. The effect on the CNV indicates greater cortical activity during higher proactive control demands. Larger N2 and P3a in incongruent trials reflect greater resource allocation to conflict monitoring and conflict resolution, i.e., reactive control. The influence of probe valence on P3a suggests reduced processing capacity due to negative information.