An event-related potential investigation of varieties of negative priming

In an event-related potential (ERP) study of varieties of negative priming (NP), 20 participants performed two basic tasks, identification and localization. NP was established in response times (RTs) for two different conditions employed in the literature, DT (distractor-target shifts between subsequent displays), and DTTD (distractor-target reversals). With identification, there were two findings specific to DTTD: reduced amplitude of frontocentral P200 and earlier onset of response-locked lateralized readiness potential (R-LRP). The pattern suggests that DTTD probes were perceived as highly similar to the prime, causing a tendency to repeat the prime response. Identity-based DT had no significant ERP correlate but was accompanied by wrong preactivation in the stimulus-locked LRP (S-LRP). Regarding localization, P300 seemed reduced with the DTTD condition. However, current-source density (CSD) analysis suggested additional frontal and occipital N2 components, indicating inhibition of a tendency to repeat the prime response and persisting inhibition of the prime distractor location, respectively. A larger frontopolar N440 accompanying spatial NP suggested attempts to resolve conflicts occurring at late stages of processing. Data support the view of NP effects being caused by different subprocesses. Furthermore, distinct brain processes seem to underlie NP obtained from DT and DTTD conditions.