The medial parietal cortex (MPC) is ubiquitously implicated in studies of human episodic memory retrieval. Interestingly, distinct subregions of MPC are engaged depending on the type of retrieval task being performed. Other types of functional dissociation have also been reported for MPC, focusing on brain network organization or stimulus selectivity. To reconcile these different functional views, we leveraged a precision-neuroimaging dataset where participants performed thousands of recognition memory trials. We observed distinct MPC subregions supporting either recognition decisions or their semantic content, which recapitulated distinct patterns of hippocampal connectivity and visual category selectivity within MPC. These findings promote a common principle of functional organization that is shared among brain regions supporting episodic memory and advances our understanding of MPC.
We used eye-tracking to quantify monitoring strategies on a moment-to-moment basis while participants performed a prospective memory task. We then related fixation times to PM costs and PM performance. We found that PM costs reflected dissociable monitoring strategies - higher costs were associated with early and frequent monitoring while lower costs were associated with delayed and infrequent monitoring. Moreover, the link between fixations and PM costs varied with cognitive load, and the inclusion of fixation data yielded better predictions of PM accuracy than using PM costs alone.
Using a novel dynamic prospective memory task, we found that individuals adjust their prospective memory strategy in response to real-time shifts in ongoing demands. These shifts seem to support the balance between ongoing task demands and transient memory needs.