Poster A54, Saturday, March 24, 1:30–3:30 pm, Exhibit Hall C
Effects of age on across-participant variability of cortical reinstatement effects
Preston Thakral1, Tracy Wang2, Michael Rugg3; 1Harvard University, 2University of Texas at Austin, 3University of Texas at Dallas
In the current functional neuroimaging study, we assessed whether age-related decline in episodic memory is associated with a reduction in the specificity of retrieved content. We addressed this question by employing across-participant multi-voxel pattern analysis (MVPA) to examine whether increasing age is associated with differences in the variability of cortical reinstatement effects. During study, participants (24 young and 24 old) viewed objects and concrete words. Test items included studied words, the names of studied objects, or unstudied words. Participants judged whether the items were recollected, familiar, or new by making ‘remember’, ‘know’ and ‘new’ responses, respectively. MVPA was conducted in regions of the ‘core recollection network’. We employed a leave-one-participant-out classification approach where the classifier was trained on a subset of the participants (young and old, young only, or old only) and tested on the data from held-out participants. Classifiers were trained on the study phase data to discriminate trials as a function of content (i.e., picture or word). The classifiers were then tested on the test phase data (i.e., study-test classification, an index of cortical reinstatement). When the classifier was trained on all participants, study-test classification was significantly above chance. Thus, cortical reinstatement effects generalize across different people. Study-test classifier accuracy did not, however, differ as a function of the age-specific classifiers (i.e., classifiers trained on young only versus old only data). These findings suggest that increasing age is not associated with a difference in the variability of cortical reinstatement effects.
Topic Area: LONG-TERM MEMORY: Development & aging