An Analysis of N2 Event-Related-Potential Correlates of Sequential and Response-Facilitation Effects in Cognitive Control

According to conflict-monitoring theory (Botvinick, Braver, Barch, Carter, & Cohen, 2001), sequential adjustments in cognitive control indicate that encountering information-processing conflict engages cognitive-control mechanisms. With 20 participants in an event-related-potential (ERP) experiment, we found significant congruence-sequence effects (CSEs) for behavioral measures and for N2 amplitude, a negative-going ERP component established in previous work to be related to cognitive control. We also found an interaction between the Stroop-trajectory manipulation and a response-compatibility manipulation for behavioral measures and, to a lesser extent, for N2 amplitude, such that the Stroop-trajectory congruence effect was larger on response-compatible than on response-incompatible trials. This study is the first to identify N2 amplitude as a neural correlate of the CSE in a confound-minimized task. Accordingly, these results found N2 amplitude to be associated with adjustments in cognitive control as a function of sequential and response-facilitation effects while also validating the Stroop-trajectory task as a confound-minimized means of assessing neural correlates of CSEs.