Representation of navigational affordances and ego-motion in the occipital place area

Humans effortlessly use vision to plan and guide navigation through the local environment, or “scene”. A network of three cortical regions respond selectively to visual scene information, including the occipital place area (OPA), parahippocampal place area (PPA), and retrosplenial complex (RSC) – but how this network supports visually-guided navigation is unclear. Recent evidence suggests that one region in particular, the OPA, supports visual representations for navigation, while PPA and RSC support other aspects of scene processing. However, most previous studies tested only static scene images which lack the dynamic experience of navigating through scenes. Accordingly, here we used dynamic movie stimuli to test whether OPA, PPA, and RSC represent two critical kinds of navigationally-relevant information: navigational affordances (e.g., can I walk to the left or right?) and ego-motion (e.g., am I turning left or right?). We found that OPA is sensitive to both affordances and ego-motion, as well as the conflict between these cues – e.g., turning toward versus away from an open doorway. These effects were significantly weaker or absent in PPA and RSC. Responses in OPA were also dissociable from those in early visual cortex, consistent with the idea that OPA responses are not merely explained by lower-level visual features. OPA responses to affordances and ego-motion were stronger in the contralateral than ipsilateral visual field, suggesting that OPA encodes navigationally relevant information within an egocentric reference frame. Taken together, these results support the hypothesis that OPA contains visual representations that are useful for planning and guiding navigation through scenes.