Examining the neural basis of episodic memory: ERP evidence that faces are recollected differently from names.

Episodic memory is supported by recollection, the conscious retrieval of contextual information associated with the encoding of a stimulus. Event-Related Potential (ERP) studies of episodic memory have identified a robust neural correlate of recollection--the left parietal old/new effect--that has been widely observed during recognition memory tests. This left parietal old/new effect is believed to provide an index of generic cognitive operations related to recollection; however, it has recently been suggested that the neural correlate of recollection observed when faces are used as retrieval cues has an anterior scalp distribution, raising the possibility that faces are recollected differently from other types of information. To investigate this possibility, we directly compared neural activity associated with remember responses for correctly recognized face and name retrieval cues. Compound face-name stimuli were studied, and at test either a face or a name was presented alone. Participants discriminated studied from unstudied stimuli, and made a remember/familiar decision for stimuli judged 'old'. Remembering faces was associated with anterior (500-700 ms) and late right frontal old/new effects (700-900 ms), whereas remembering names elicited mid frontal (300-500 ms) and left parietal (500-700 ms) effects. These findings demonstrate that when directly compared, with reference to common episodes, distinct cognitive operations are associated with remembering faces and names. We discuss whether faces can be remembered in the absence of recollection, or whether there may be more than one way of retrieving episodic context.