The influence of crowding and cortical spacing on visual working memory

Poster Session B - Sunday, March 30, 2025, 8:00 – 10:00 am EDT, Back Bay Ballroom/Republic Ballroom

Taryn Green¹ (tgre116@lsu.edu), Naria Quazi², Jason Scimeca¹; ¹Louisiana State University, ²University of California, Berkeley

The neural basis of visual working memory (VWM) remains contentious. One prominent theory, the sensory recruitment hypothesis, posits that the visual cortex both perceives and maintains visual information. In contrast, competing theories propose that only cortical regions outside visual cortex maintain visual information after perception. The current study addresses this debate by investigating the effects of spatial crowding – constraints on cognition due to object spacing that are typically observed during perception – on VWM maintenance. We hypothesized that crowding would influence cortical competition in visual cortex during maintenance and impair VWM performance, even if crowding cannot occur during initial perception. In Experiment 1, we address this hypothesis using a VWM recall task for color. Participants encoded five sequentially-presented colored squares that were displayed at locations either closer together (crowded in space) or farther apart. At test, a single location was highlighted and participants used a continuous color wheel to report the color of the probed location. In Experiment 2, we address this hypothesis using a VWM recall task for spatial orientation. We found significantly impaired memory for objects initially presented closer together compared to objects presented farther apart. Model-based analyses revealed that this difference in VWM performance was due to an increase in spatial binding errors, instead of a decrease in memory precision for the remembered feature. Together, these results emphasize the importance of spatial crowding on VWM maintenance and support the hypothesis that cortical competition in visual cortex is an important constraint on working memory performance.

Topic Area: EXECUTIVE PROCESSES: Working memory