Electrophysiological correlates of exemplar-specific processes in implicit and explicit memory.
The present ERP study investigated the retrieval of task-irrelevant exemplar-specific information under implicit and explicit memory conditions. Subjects completed either an indirect memory test (a natural/artificial judgment) or a direct recognition memory test. Both test groups were presented with new items, identical repetitions, and perceptually different but conceptually similar exemplars of previously seen study objects. Implicit and explicit memory retrieval elicited clearly dissociable ERP components that were differentially affected by exemplar changes from study to test. In the indirect test, identical repetitions, but not different exemplars, elicited a significant ERP repetition priming effect. In contrast, both types of repeated objects gave rise to a reliable old/new effect in the direct test. The results corroborate that implicit and explicit memory fall back on distinct cognitive representation and, more importantly, indicate that these representations differ in the type of stimulus information stored. Implicit retrieval entailed obligatory access to exemplar-specific perceptual information, despite its being task irrelevant. In contrast, explicit retrieval proved to be more flexible with conceptual and perceptual information accessed according to task demands.
Brain & Cognition Unit, Department of Psychology, Saarland University, Campus A2 4, 66123 Saarbruecken, Germany. kristina.kueper@mx.uni-saarland.de
Kristina
K
Küper
Christian
C
Groh-Bordin
Hubert D
HD
Zimmer
Ullrich K H
UK
Ecker
D000328:Adult; D001931:Brain Mapping; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D007600:Judgment / Q000502:physiology*; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology; D060865:Repetition Priming / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult