Long-term memory specificity for faces depends on inhibition of closely related items
Brittany M. Jeye1, Scott D. Slotnick1; 1Boston College
We previously found that long-term memory inhibition occurred for distantly related abstract shapes. Related shapes were constructed by morphing old shapes from 50 to 200% (100% morphs were perceptually “different” from the corresponding old shapes). The “old” response rate was lower for 200% morphs than for new shapes, which can be attributed to inhibition of distantly related items. In the current study, we evaluated the specificity of long-term memory representations for faces. During the encoding phase, participants were presented with neutral Caucasian male and female faces. During the retrieval phase, old faces, related faces, and new faces were presented and participants made “old”–“new” recognition judgments. Related faces were created by morphing along a five step continuum (20–100%) between old faces and unique new faces (independent ratings indicated that the pairs of morphed faces were perceptually dissimilar). As expected, memory representations were very specific as the “old” response rate was significantly greater for old faces than 20% morphs. Moreover, the “old” response rate was significantly lower for 20% morphs than for 40% morphs, which likely reflects memory inhibition of closely related faces. These results suggest that long-term memory specificity depends on detailed memory for specific faces and inhibition of closely related faces. This may reflect an evolutionary advantage for recognizing specific faces, which may require inhibition of closely related faces (as compared to abstract shapes that have less specific category boundaries). We are currently designing a follow-up ERP study to investigate the brain basis of this long-term memory inhibition.
Topic Area: LONG-TERM MEMORY: Episodic