Inferential Eye Movement Control while Following Dynamic Gaze

Abstract

Attending to other peoples gaze is evolutionary important to make inferences about intentions and actions. Gaze influences covert attention and triggers eye movements. However, we know little about how the brain controls the fine-grain dynamics of eye movements during gaze following. Observers followed peoples gaze shifts in videos during search and we related the observer eye movement dynamics to the timecourse of gazer head movements extracted by a deep neural network. We show that the observers brains use information in the visual periphery to execute predictive saccades that anticipate the information in the gazers head direction by 190-350 ms. The brain simultaneously monitors moment-to-moment changes in the gazers head velocity to dynamically alter eye movements and re-fixate the gazer (reverse saccades) when the head accelerates before the initiation of the first forward gaze-following saccade. Using saccade-contingent manipulations of the videos, we experimentally show that the reverse saccades are planned concurrently with the first forward gaze-following saccade and have a functional role in reducing subsequent errors fixating on the gaze goal. Together, our findings characterize the inferential and functional nature of the fine-grain eye movement dynamics of social attention.