TEMPORAL DYNAMICS OF INFORMATION REPRESENTATION IN PREFRONTAL AND PARIETAL CORTICES DURING GOAL-DIRECTED MEMORY RETRIEVAL

The ability to retrieve goal-relevant information from memory is fundamental to adaptive behavior in everyday contexts. Prior work has implicated the prefrontal and parietal cortices in monitoring and controlling the activation of goal-relevant information during memory retrieval. However, the nature of the information represented within these regions during such control processes remains unclear. We hypothesized that the information represented in prefrontal and parietal regions dynamically changes over time to support behavior. To test this hypothesis, we conducted an event-related functional magnetic resonance imaging (fMRI) experiment. Participants performed a selective retrieval task, in which they retrieved a cued object from previously learned real-world scenes containing multiple objects. Separate object and scene perception tasks were also administered. Comparisons of multivoxel response patterns between retrieval and perception revealed transient representations during the early phase of retrieval. During this phase, non-target objects were encoded in the dorsolateral prefrontal cortex (dlPFC), whereas target objects were encoded in the angular gyrus (AG) and superior parietal lobule (SPL). In contrast, during the later phase of retrieval, no significant similarity between retrieval and perception was observed; instead, retrieval cue-specific representations were stably maintained in the dlPFC, AG, and SPL. Moreover, pattern similarity analysis across adjacent time points revealed dynamically changing neural representations during the early phase, followed by stable and temporally consistent representations in the later phase. Together, these findings suggest that goal-directed memory retrieval is supported by temporally dynamic information processing within prefrontal and parietal cortices.

Supported by NRF of Korea (RS-2024-00459828) and SNU Creative-Pioneering Researchers Program.