Poster Session E, Monday, March 25, 2:30 – 4:30 pm, Pacific Concourse
Cortical reinstatement in young and older adults
Paul F. Hill1, Danielle R. King1, Joshua D. Koen2, Michael D. Rugg1; 1Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, 2Department of Psychology, University of Notre Dame
Patterns of cortical activity elicited during recollection overlap with patterns elicited by the initial experience of the recollected event (‘cortical reinstatement’), and this retrieval-related activity is widely held to represent the ‘content’ of recollection. Hence, age-related differences in the strength of cortical reinstatement may contribute to age-related differences in the accuracy and specificity of recollection. Here, young (N=24, mean age 22 years) and older (N=24, mean age 70 years) adults underwent fMRI as they studied words paired with images of faces or scenes. At test, participants performed recognition judgments on old and new test words and, for each recognized word, tried to recall the category of the image paired with it at study. Using univariate analyses of mean-signal change, we operationalized cortical reinstatement as regions where category-selective encoding and recollection effects overlapped. To identify recollection effects that were unique to each image class, we exclusively masked each category-selective recollection contrast (source correct > source incorrect) with the analogous recollection contrast. We then inclusively masked the resulting recollection contrasts with the corresponding category-specific encoding contrasts (i.e., face > scene, scene > face). To eliminate potential reinstatement effects that varied by age, we exclusively masked each category-selective effect with the respective age by recollection interaction contrast. This procedure identified robust reinstatement effects for both faces (in precuneus and bilateral anterior medial temporal lobe) and scenes (in parahippocampal and retrosplenial cortex). In both cases, the effects were age-invariant. The data support prior findings suggesting that category-level cortical reinstatement effects are insensitive to age.
Topic Area: LONG-TERM MEMORY: Episodic