Tracking the emergence of concrete and abstract working memory representations guiding future cognition in the intraparietal sulcus and visual cortex

Poster Session B - Sunday, April 14, 2024, 8:00 – 10:00 am EDT, Sheraton Hall ABC

Jongmin Lee¹ (jongmin.lee.529@gmail.com), David De Vito¹, Jacob A. Miller², Derek Evan Nee; ¹Department of Psychology, Florida State University, ²Wu Tsai Institute, Department of Psychiatry, Yale University

Working memory (WM) sustains the recent past to guide future cognition. The sensory recruitment hypothesis posits that WM is supported by persistent sensory codes. However, evidence for sensory recruitment comes largely from paradigms which focus retrospectively on the past, rather than prospectively on the future. To examine prospective WM, we tested participants with a sequence memory task wherein they determined whether the currently presented stimulus sequentially followed from the last stimulus presented in the same visual field. On each trial, participants maintained a spatial location in each of the left and right visual fields. An arrow cue indicated whether a forthcoming probe would appear in the left or right visual field. We hypothesized that during the cue-probe delay, participants would generate a prospective code of the next item in the sequence (NIS). Furthermore, we hypothesized that the prospective code would be informed by abstract sequence knowledge over-and-above concrete field-specific sensory information. Analysis of fMRI signals in the intraparietal sulcus (IPS) and visual cortex (VC) revealed that the neural representation of the previously presented stimulus transitioned into that of NIS in both regions. Furthermore, we found that location representations in IPS generalized across visual fields, indicating an abstract representation of position in the sequence over-and-above concrete sensory information. Such abstract representation was not clearly present in VC. Taken together, these results indicate that the IPS stores abstract codes to guide future cognition indicating contributions to WM beyond sensory recruitment.

Topic Area: EXECUTIVE PROCESSES: Working memory