Poster D90, Monday, March 27, 8:00 – 10:00 am, Pacific Concourse
How does pre-existing person knowledge affect source memory? Event-Related Potentials dissociate effects of person knowledge and recollection.
Graham MacKenzie1, Peter J.B. Hancock1, David I. Donaldson1; 1University of Stirling
Recognition memory is better for faces of people we know than for unfamiliar faces, and this benefit presumably arises from a greater facility to recollect information associated with semantic knowledge. To assess whether and how person knowledge affects recollection, a face-colour source memory task was performed for famous and unfamiliar faces. To ensure that task performance reflected face rather than picture recognition, different photos of studied faces were used as test items before source colour judgments were made for recognised faces. A familiarity check was performed to exclude famous identities unknown to participants from analysis. Both item recognition and source memory were better for famous than unfamiliar faces. Event-Related Potential (ERP) old/new effects from 300-500msec displayed frontal versus parietal maxima for famous and unfamiliar faces, respectively. From 500-700msec, the famous effect was larger than the unfamiliar effect. We additionally examined ERP effects of person knowledge by contrasting famous and unfamiliar waveforms directly for source correct and correct rejection conditions. In both cases, person knowledge was linked with frontal effects from 300-700msec – although with a more widespread distribution from 500-700msec for source memory. The difference between these source correct and correct rejection person knowledge effects revealed a pattern of left parietal activity (500-700msec), which suggests that neural activity linked with person knowledge is dissociable from the left parietal signature of recollection. Person knowledge clearly enhances source memory; in the absence of pre-experimental person knowledge recollection for unfamiliar faces is difficult and additional cognitive operations linked to semantic processing are recruited.
Topic Area: LONG-TERM MEMORY: Episodic