Sihan Yang¹, Yueying Dong¹, Anastasia Kiyonaga¹; ¹University of California, San Diego

Visual working memory (VWM) temporarily stores visual information to guide behavior but is also modulated by expected actions and contextual factors. Prior studies show that the same VWM information can evince different neural representations or be perceived differently depending on the expected response format. VWM recall can also be biased by the features of other items concurrently perceived (i.e., surrounding bias) or from the recent past (i.e., serial bias), and these contextual biases may be modulated by motor and response demands. Here, we show how the VWM motor response modality influences the manifestation of spatial and temporal contextual biases. Participants viewed two Gabor patches and reported their orientation after a short delay using a digital pen. In half of the blocks, they responded in the conventional way by continuously adjusting a probe wheel (‘clicking’). In the other blocks, they reported by drawing a line that matched the remembered orientation (‘drawing’). In general, we observed typical surrounding and serial biases in that recall was repelled from the concurrently-presented stimulus but attracted toward the relevant stimulus from the previous trial. We also found that the magnitude of both biases changed with response modality and predictability, even when perceptual inputs and memory content were matched. For instance, the serial bias was magnified for drawing responses (vs. clicking) when participants were able to prepare their motor plan during the delay. In a follow-up study using eye-tracking, we observed that gaze patterns showed progressively more serial bias across the delay for drawing conditions (but not clicking), revealing that peripheral oculomotor signatures can flexibly track the development of contextual biases. These results highlight how the integration of contextual information and visuomotor transformation interweave in VWM, emphasizing that VWM biases may be expressed differently depending on upcoming action demands.