Sanika Paranjape¹, Simon Kaplan¹, Sarah Shomstein¹, Dwight J. Kravitz^1,2; ¹The George Washington University, ²US National Science Foundation (SBE/BCS)

The sensorimotor recruitment theory of visual working memory (VWM) posits that the same cortical areas are recruited for both encoding and maintenance, suggesting that memory influences ongoing perception, and ongoing perception influences memory. Previous studies show that this bidirectional relationship exists for low-level features (e.g. orientation and color). However, it is unclear whether this bidirectional relationship is unique to low-level features or extends to high-level complex stimuli. We hypothesized that, for motion direction and face identity, stimuli held in VWM influence ongoing perception, consistent with the common recruitment of motion area MT and face-selective FFA/OFA for VWM and perception. In a series of experiments, two discrimination conditions were used: 1) the middle condition, in which the two discrimination stimuli are equidistant from the maintained stimulus (in a continuous stimulus space); and 2) the side condition, in which both discrimination stimuli are off to one side. The maintained information predictably interfered with discrimination, both decreasing and increasing discriminability depending on the relationship of the maintained and discriminated information. Moreover, the discrimination stimuli introduced systematic biases in the continuous report of the maintained information. We further tested the effect of delay, hypothesizing a theta rhythm in the strength of interference effects. For motion, the strength of this interference was modulated by the time between encoding and discrimination, evidencing sustained interference and systematic theta oscillations. This oscillatory pattern and decay over time was not found for faces, highlighting the robust and complex nature of faces and their resistance to decay. Overall, the results suggest that sensory recruitment is a general VWM mechanism, not limited to maintenance of low-level features. The inconsistency between faces and motion in the temporal pattern of the interference is consistent with the recruitment of distinct neural circuits for different visual information, resulting in different specific dynamics.

Acknowledgements: NSF BCS-2022572 to SSS and DJK; W911NF-23-2-0097 to DJK and SRM