Poster D114, Monday, March 26, 8:00-10:00 am, Exhibit Hall C
Parietal and occipitotemporal cortical reinstatement differentially predict successful associative memory retrieval in older adults
Alexandra N. Trelle1, Valerie A. Carr2, Scott Guerin1, Wanjia Guo1, Marc B. Harrison1, Manasi Jayakumar1, Jiefeng Jiang1, Geoffrey Kerchner1, Elizabeth Mormino1, Natalie Tanner1, Monica Thieu3, Anthony D. Wagner1; 1Stanford University, 2San Jose State University, 3Columbia University
In healthy younger adults, reactivation of encoding-related cortical activity patterns during memory retrieval is associated with superior episodic memory. Recent data suggest that, relative to activity patterns in occipitotemporal cortex, reinstatement in ventral parietal cortex may be differentially linked with behavioural memory outcomes. The present study examined this possibility in healthy older adults using high-resolution fMRI data collected during a paired-associate encoding and retrieval task. Participants studied a series of word-face and word-scene pairs, and subsequently made memory decisions on studied words intermixed with novel words. During retrieval, participants indicated the category of the paired associate (“face” or “scene”), responded "old" when recognizing the word without associative recollection (item memory only), or responded "new". An additional post-scan test probed whether participants could recollect the specific picture associated with each studied word. Encoding-retrieval pattern similarity (ERS) analyses revealed evidence for stronger reinstatement of item-level and category-level associative information in inferior parietal cortex (IPL), inferior frontal gyrus (IFG), and ventral occipitotemporal cortex (VOTC) during successful associative retrieval (word and correct category) relative to item recognition (“old” judgement). Mixed effect models revealed that, relative to reinstatement in VOTC or IFG, the magnitude of trial-level reinstatement in IPL better predicted behavioral measures of associative retrieval during scanning and recollection of the specific associate post-scanning. These results complement extant findings in younger adults, and provide novel evidence for a role of IPL in representing behaviourally relevant mnemonic content during memory retrieval across the lifespan.
Topic Area: LONG-TERM MEMORY: Development & aging