Recurrent processing in Aphantasia

Poster Session F - Tuesday, April 16, 2024, 8:00 – 10:00 am EDT, Sheraton Hall ABC

Corey Loo^1,2, Bradley Buchsbaum^1,2; ¹University of Toronto, ²Rotman Research Insitute, Baycrest

Though mental imagery is thought to play an essential role in human cognition, there are people who are unable to form voluntary images and yet have no obvious cognitive deficits—a condition that has been called aphantasia. We hypothesize that aphantasia may involve a tendency to operate on perceptual representations at higher levels of abstraction, coupled with a lack of high-to-low level feedback processes, which are thought to be important for vivid visual imagery. In this work we attempt to isolate such recurrent processing using a perceptual pattern completion task with a backward masking manipulation. Perceptual pattern completion is thought to be supported by recurrent processing whereby activation from a partial cue spreads to missing features. This recurrent processing can be inhibited through backward masking. But since individuals with aphantasia may avoid—or have a deficit with respect to—such recurrent processing, is their performance differentially impacted by visual backward masking? We recruited thirty-four individuals with aphantasia to complete a backward-masking task in which we briefly presented participants with partially occluded images and asked them to categorize the shown object into one of four categories. Crucially, these partial images were followed by a visual noise mask, aimed at disrupting recurrent processing that is thought to support pattern separation. We initially expected to find that individuals with aphantasia would be undisrupted by backwards masking, instead finding that they were more impacted by backwards masking relative to controls. This suggests they have intact, but poor, recurrent processing and are thus more susceptible to visual interference.

Topic Area: OTHER