Gaze direction aftereffects are surprisingly long-lasting.

Adaptation to gaze direction induces aftereffects in the perception of gaze in subsequently presented faces. Gaze adaptation calibrates neural responses to the most frequently occurring gaze signals and therefore frees up capacity to respond to more novel signals, likely enhancing gaze discrimination and supporting novelty detection. The longevity of aftereffects can provide some insight into the temporal window over which this calibration occurs. Since gaze direction is a rapidly changing signal in the face, one might expect gaze aftereffects to also be very short-lived. Here we show that this is not the case. In Experiment 1, we measured participants' aftereffects immediately after gaze adaptation and 24 h later. We found significant aftereffects at both times. In Experiment 2, we tested whether long-term adaptation also occurred when aftereffects were measured only once, 24 h after adaptation. Again, we found significant long-term aftereffects. These results demonstrate that gaze adaptation can integrate information over remarkably long periods. We discuss the implications of the longevity of gaze direction aftereffects on our understanding of their functionality, and the functionality of face aftereffects more generally. (PsycINFO Database Record (c) 2016 APA, all rights reserved).