Abstract
A person’s gaze reveals much about their focus of attention and desires, and as such, perceiving gaze is important for typical social interaction. The direction of a person’s gaze is determined by integrating local information from the eyes with the rotation of the head. This interaction produces a striking illusion, known as the Wollaston effect, where a person’s gaze is pulled in the direction of the head’s rotation. If perceiving gazes directed toward one’s self is especially important, then the visual system may optimize this integration around the categorical boundary of leftward/rightward gaze and produce a repulsive perceptual effect. We tested this prediction and found converging evidence to support it. First, head rotations around the leftward/rightward category boundary produced a stronger pull on perceived gaze than equivalent rotations further away from the boundary (e.g., slightly rotating a straightforward head pulled gaze by 8º, whereas an equivalent rotation of an already-rotated head only pulled gaze by 4º). Second, the magnitude of this pulling effect was strongest when local eye information was near the category boundary; head rotations pulled straightforward eyes more strongly than they pulled averted eyes. The illusion we utilized is predicated on the integration of local information across a head, suggesting that the categorical perception of gaze originates in high-level stages of visual processing. Our results combine with similar findings in the perception of biological motion to provide growing evidence that repulsive effects underlie the categorical perception of many social features.
Meeting abstract presented at VSS 2013