Event‐related potential N 270 delayed and enhanced by the conjunction of relevant and irrelevant perceptual mismatch

• Published in: Psychophysiology Vol. 51; no. 5; pp. 456 - 463
• Main Authors: Bennett, Matthew A., Duke, Philip A., Fuggetta, Giorgio
• Format: Journal Article
• Language: English
• Published: 01.05.2014
• ISSN: 0048-5772; 1469-8986
• DOI: 10.1111/psyp.12192

Abstract Event‐related potential studies using delayed match‐to‐sample tasks have demonstrated the presence of two components, N 270 and N 400, possibly reflecting the sequential processing of multiple sources of endogenous mismatch. To date, studies have only investigated mismatch between a single cue and target. In this study, we used distractor stimuli to investigate the effect of a secondary source of mismatch distinct from the task‐relevant stimulus. Subjects performed two paradigms in which the cue and target could match or mismatch. In one paradigm, task‐irrelevant distractors were added—producing a source of task‐irrelevant perceptual mismatch. A mismatch‐triggered negativity was elicited in both paradigms, but was delayed and enhanced in magnitude in the distractors present paradigm. It is suggested that the distractors may differentially affect mismatch responses through the generation of a task‐irrelevant mismatch response.