Abstract
The functional topography of the motor cortex represents natural movement patterns (Aflalo and Graziano, 2011). Here we asked if such movement patterns are already represented at the beginning of the perception-action cycle in that visual areas represent the motor programs that are typically used in looking at specific visual stimuli. Specifically, we investigated whether the fusiform face area (FFA) and the parahippocampal place area (PPA) contain a representation of gaze patterns that are used when looking at faces or houses. For this purpose, we instructed observers to follow a dot presented on a uniform background. In Experiment 1 and 2, the dot's movement represented 3000ms of the gaze path acquired from an independent observer while looking at face or house pictures. Results from Experiment 1 showed that face- and house-associated gaze patterns could be discriminated by multivariate pattern analysis in FFA and PPA. This discrimination was still observed when gaze dispersion differences were controlled in Experiment 2. To control differences in the physical properties of the visual stimuli, in Experiment 3, the dot's movement represented the first 600ms of the gaze path acquired from either the current observer or from another observer of the sample (who would receive the first observer's gaze paths as the "other" path). We found that only the own face- and house-associated gaze patterns could be discriminated, underlining the individual nature of gaze patterns and ruling out stimulus differences as confounds. The discrimination of the observer's gaze patterns was specific to FFA and PPA, but was not observed in early visual areas (V1 - V5/MT). Moreover, the individual decoding accuracy in FFA was correlated with the accuracy in following the gaze patterns. These findings indicate that FFA and PPA represent complex gaze patterns that are used to explore the visual object categories represented in these areas.
Meeting abstract presented at VSS 2018