Neural correlates of conflict processing.

In this study we examined the neural correlates of conflict processing in the Stroop, counting, and digit-location tasks using event-related brain potentials (ERPs). The behavioral data revealed robust interference in response time and accuracy for all tasks. The interference effect for response time was greater in the Stroop task than the other tasks; in contrast, the interference effect for response accuracy was greater in the counting tasks than the other tasks. The N450 and sustained potential (SP) were elicited in each task. Partial least-squares (PLS) analysis was used to examine the structural relationships between the ERPs, task design, and behavior. TaskPLS analysis revealed that the N450 and SP were associated with a single latent variable leading to the suggestion that a common set of neural generators was recruited during conflict processing across the tasks and that there were differences between ERPs related to early processing across the three tasks. BehavioralPLS analysis revealed that the amplitude of the SP was positively correlated with response time and accuracy, indicating that this modulation of the ERPs may be related to response selection rather than to conflict resolution.