Parietal Cortex Codes for Egocentric Space beyond the Field of View

SummaryOur subjective experience links covert visual and egocentric spatial attention seamlessly. However, the latter can extend beyond the visual field, covering all directions relative to our body. In contrast to visual representations [1, 2, 3 and 4], little is known about unseen egocentric representations in the healthy brain. Parietal cortex appears to be involved in both, because lesions in it can lead to deficits in visual attention, but also to a disorder of egocentric spatial awareness, known as hemispatial neglect [5 and 6]. Here, we used a novel virtual reality paradigm to probe our participants’ egocentric surrounding during fMRI recordings. We found that egocentric unseen space was represented by patterns of voxel activity in parietal cortex, independent of visual information. Intriguingly, the best decoding performances corresponded to brain areas associated with visual covert attention and reaching, as well as to lesion sites associated with spatial neglect.

► We studied neural coding of egocentric directions beyond the visual field ► Virtual reality and participant training allowed to sample egocentric neural code ► Parietal sites associated to reaching and to neglect coded egocentric directions ► Coding mechanism of unseen egocentric space differs from that of visual space