Visuospatial working memory is cortically enabled through veridical, categorical and semantic representations

A single visual stimulus can elicit multiple concurrent representations throughout the cortex. We show that during a visual working memory task several cortical regions utilize categorical, semantic, and spatial representational formats to maintain visual stimuli in a robust fashion. We assessed the nature of orientation representations in an fMRI dataset of 40 participants performing an orientation memory task using multivariate encoding modelling. Our results show that orientation representations across the cortex form a gradient of abstraction, with more veridical representations in sensory areas and more abstract, categorical codes in anterior areas. We use cross-condition modelling to demonstrate shared neural codes between orientation and congruent verbal and location stimuli, used at different points during the trial. These findings provide evidence for a distributed account of working memory storage, where memory representations, distinct in nature and content, are present concurrently throughout the cortex.