Spatial selectivity in adaptation to gaze direction.

A person's focus of attention is conveyed by the direction of their eyes and face, providing a simple visual cue fundamental to social interaction. A growing body of research examines the visual mechanisms that encode the direction of another person's gaze as we observe them. Here we investigate the spatial receptive field properties of these mechanisms, by testing the spatial selectivity of sensory adaptation to gaze direction. Human observers were adapted to faces with averted gaze presented in one visual hemifield, then tested in their perception of gaze direction for faces presented in the same or opposite hemifield. Adaptation caused strong, repulsive perceptual aftereffects, but only for faces presented in the same hemifield as the adapter. This occurred even though adapting and test stimuli were in the same external location across saccades. Hence, there was clear evidence for retinotopic adaptation and a relative lack of either spatiotopic or spatially invariant adaptation. These results indicate that adaptable representations of gaze direction in the human visual system have retinotopic spatial receptive fields. This strategy of coding others' direction of gaze with positional specificity relative to one's own eye position may facilitate key functions of gaze perception, such as socially cued shifts in visual attention.