Flanker paradigm contains conflict and distraction factors with distinct neural mechanisms: an ERP analysis in a 2-1...

Behavioral studies using the flanker 2-1 mapping task suggest that both stimulus and response conflicts contribute to flanker conflict effect. However, both are intertwined with distraction effect. Their underlying neural mechanisms remain unclear. We applied a perceptual flanker 2-1 mapping task to 24 healthy young adults, while the event-related potentials were recorded. The task included stimulus-incongruent (SI), response-incongruent (RI), congruent (CO) and neutral (NE) stimuli. Our reaction time data demonstrated conflict effect, distraction effect and their interaction. Furthermore, the conflict factor successively enhanced the frontal P2 (160-240 ms), the posterior N2pc (200-240 ms), the fronto-central and the right frontal N2b (240-420 ms), and the posterior N2c (320-420 ms). Only the frontal P2 was larger for RI than SI. The distraction factor increased the right N2pc and reduced the left parietal P3b (460-480 ms). Overall, our findings suggested that the flanker conflict involved an early attentional processing of task-relevant and distractive information, and a later processing of conflict evaluation and response inhibition.