EVENT-RELATED BRAIN POTENTIALS ELICITED BY AFFECTIVE AND NON-AFFECTIVE PICTORIAL STIMULI

Abstract

The study was designed to meet three goals: to investigate whether the occurrence of affective mismatch would elicit N400 component of the ERP, to identify potentially distinct ERP signatures of affective mismatch, and to investigate the possibility of differing processing that occur for affective and semantic mismatches. To this end, a modified oddball paradigm and emotional (positive and neutral) pictorial stimuli were employed. It was found that affective mismatch elicited N400 component with a maximal negativity in the anterior sites. In addition to N400 component, negative slow wave (nSW) differentiated the affective and semantic conditions; affective condition exhibited maximum negativity at posterior sites while the semantic condition displayed maximum negativity at anterior sites. The findings were discussed, in part, with respect to LeDoux's ( 1989) conceptualization of separate cognitive and emotional systems in the brain. The implications of the findings were discussed in view of the strengths and limitations of the study.