Visual Working Memory Enhances the Neural Response to Matching Visual Input

Visual working memory (VWM) is used to maintain visual information available for subsequent goal-directed behavior. The content ofVWM has been shown to affect the behavioral response to concurrent visual input, suggesting that visual representations originating fromVWMand from sensory input draw upon a shared neural substrate (i. e., a sensory recruitment stance onVWMstorage). Here, we hypothesized that visual information maintained inVWMwould enhance the neural response to concurrent visual input that matches the content ofVWM. To test this hypothesis, we measured fMRI BOLD responses to task-irrelevant stimuli acquired from 15 human participants (three males) performing a concurrent delayed match-to-sample task. In this task, observers were sequentially presented with two shape stimuli and a retro-cue indicating which of the two shapes should be memorized for subsequent recognition. During the retention interval, a task-irrelevant shape (the probe) was briefly presented in the peripheral visual field, which could either match or mismatch the shape category of the memorized stimulus. Weshow that this probe stimulus elicited a strongerBOLDresponse, and allowed for increased shape-classification performance, whenit matched rather than mismatched the concurrently memorized content, despite identical visual stimulation. Our results demonstrate thatVWMenhances the neural response to concurrent visual input in a content-specific way. This finding is consistent with the view that neural populations involved in sensory processing are recruited forVWMstorage, and it provides a common explanation for a plethora of behavioral studies in whichVWMmatching visual input elicits a stronger behavioral and perceptual response.