Abstract
Visual features of separable dimensions like color and shape can conjoin to represent an integrated object. We investigated how mid-level visual features bind to form a complex visual scene. Specifically, we focused on features important for visually guided navigation: direction and distance. Previously, separate works have shown that directions and distances of navigable paths are coded in occipital place area (OPA). We tested how separate features are concurrently represented in OPA. Participants saw eight different types of scenes (2: number of paths, 2: directions, 2: distances) in the fMRI scanner (N = 20). In single-path scenes, path direction was either to the left or to the right. In double-path scenes, both directions were present. Each path contained a glass wall located either near or far, changing the navigational distance. We hypothesized that OPA represents paths as a combination of direction and distance. OPA’s multi-voxel pattern similarities were analyzed, and voxel-wise linear combinations for scene pairs were computed for comparison. Results showed that OPA’s representations of single-path scenes were similar to other single-path scenes of either the same direction or the same distance. Representations of double-path scenes were based on a combination of two corresponding single-path units. Specifically, a double-path scene (e.g., Left-Near Right-Far) consisted of an average of two single-path scenes with specific directions and distances (e.g., Left Near+Right Far) rather than a pooled representation of all features (Left+Near+Right+Far). These results suggest that when navigational distance is unambiguously attributed to a single path direction, OPA represents distance and direction independently. Contrastingly, OPA combines the two features to form an integrated representations of path units in multiple-path scenes. Altogether, these results suggest that visually guided navigation may be supported by OPA’s ability to quickly combine multiple features relevant for navigation and represent a navigational file.