New insights into the Stroop effect: a spatiotemporal analysis of electricbrain activity

Recent clinical and imaging studies suggest the involvement of anterior bra in regions in the Stroop effect without providing consensus on the hemisphe re being involved. Here, we investigated the dynamics of brain activation d uring a modified Stroop task using behavioural, event-related potential map series, and source localization analysis. Behavioural analysis showed an i ncreased RT in the interference (IC) as compared to the neutral (NC) and co ngruence conditions (CC). Map series analysis in these conditions displayed a similar sequence of 10 stable segments. From these, only segment S6, occ urring at similar to 300 ms and displaying a dominant right anterior activa tion, was of increased duration in IC. Furthermore, in IC only, RT was show n to correlate with S6 duration. These results are discussed in terms of in creased duration of an attentional process needed to solve the conflict. Ne uroReport 11:1849-1855 (C) 2000 Lippincott Williams & Wilkins.