N200 in the flanker task as a neurobehavioral tool for investigating executive control

Abstract

Event-related potentials were recorded in a flanker task using arrowheads pointing to the left or to the right as targets and as congruent or incongruent flanker stimuli using squares as neutral flanker stimuli. The onset of the flanker stimuli preceded that of the target stimuli by 100 ms. Lateralized readiness potentials showed response activation below execution threshold in correspondence to the information conveyed by the flanker stimuli. Exclusively, the incongruent flanker condition provoked a N2c, which evolved closely synchronized to the erroneous response. Graded response analyses separating incongruent trials with weak, medium, and strong incorrect response activation revealed that the N2c amplitude covaried with the magnitude of the erroneous response. The N2c in the incongruent compatibility condition of the flanker task thus corresponds to the avoidance of inappropriate responses, possibly reflecting the inhibition of automatically but erroneously primed responses. The results are compatible with studies of error correction, suggesting that efference monitoring is a constituent of executive control.

Event-rate effects in the flanker task: ERPs and task performance in children with and without AD/HD

“…The N2, or "control N2", is a fronto/fronto-central negativity occurring between 200 and 400 ms after stimulus presentation in children (Folstein and Van Petten, 2008;Johnstone et al, 2010). In the flanker task the N2 is enhanced to incongruent stimuli compared to other stimuli (Heil et al, 2000;Johnstone et al, 2009;Johnstone et al, 2010;Kopp et al, 1996;Yeung et al, 2004).…”

“…This enhancement of N2 has been explained in terms of conflict monitoring (Yeung et al, 2004), with N2 amplitude indexing a conflict monitoring process that occurs due to the coactivation of incompatible responses in the incongruent condition (i.e., simultaneous left and right responses; Kopp et al, 1996). Following this, it was expected that a conflict-processing deficit in children with AD/HD would manifest in the amplitude difference between incongruent and neutral stimuli (i.e., the effect of conflicting response information compared to typical non-conflict response processing).…”

“…The flanker task is thought to measure interference control (Sanders and Lamers, 2002), requiring the participant to attend to task-relevant stimuli whilst concurrently inhibiting task-irrelevant stimuli (van Veen et al, 2001). Incongruent flankers provide response information that conflicts with the response information of the target stimuli (i.e., one requires a left-handed response and the other requires a right-handed response), resulting in an interference effect that is characterised by a slower reaction time (RT) and a greater number of errors (Kopp et al, 1996). Conversely, in the congruent condition the target stimulus and the flanking stimuli provide complementary response information (i.e., they both denote the same response) that facilitates a reduction in RT and errors (Flowers, 1990).…”

Interactions of focal cortical lesions with error processing: Evidence from event-related brain potentials.

“…Kopp, Rist, & Mattler, 1996). Participants had to respond as fast and as accurately as possible to a target arrow briefly presented in the center of the screen.…”

“…Falkenstein et al, 2000;Kopp et al, 1996). These amplitude measures at FCz were subjected to ANOVAs with the between-subjects factor Group (two levels) and the withinsubjects factor Response Type (two levels).…”