Filling a blank canvas

Abstract

Neuroscience Natural scenes can be decoded in the brain in the early visual cortex. Decoding is a product of planned output (feedforward) corrected by experience (feedback). Morgan et al. occluded one quadrant of the visual field of human participants and then presented them with images of landscape scenes. Responses in the visual cortex (areas V1 and V2) were measured for each person by functional magnetic resonance imaging. Even in the occluded region, information about the scene was being decoded. To access what the brain had modeled for the occluded region, participants were asked to complete the image by line drawings on an electronic drawing tablet. The drawings were shown to all participants, who scored how well the “averaged” drawing for each scene matched the complete image. Mental models at the first visual cortical stage were predicted by the line drawings. So, faced with a blank canvas, an artist may be using cortical feedback processing until the lines and edges converge on her mental model of a scene, thus providing a window into her visual cortex. J. Neurosci. 39 , 9410 (2019).