Eye gaze direction shows a positive serial dependency.

Recent work from several groups has shown that perception of various visual attributes in human observers at a given moment is biased towards what was recently seen. This positive serial dependency is a kind of temporal averaging which exploits short-term correlations in visual scenes to reduce noise and stabilize perception. Here we test for serial dependencies in perception of head and eye direction using a simple reproduction method to measure perceived head/eye gaze direction in rapid sequences of briefly presented face stimuli. In a series of three experiments, our results reveal that perceived eye gaze direction shows a positive serial dependency for changes in eye direction, along both the vertical and horizontal dimensions, although more strongly for horizontal gaze shifts. By contrast, we found no serial dependency at all for horizontal changes in head position. These findings show that a perception-stabilizing 'continuity field' operates on eye position-well known to be quite variable over short timescales-while the more inherently stable signal from head position does not.