Visual representation of the gaze-imitation task.

<p>After gaze-fixation participants watched video-clips wherein faces fluently shifted from neutral to fearful or happy expressions, while the eyes shifted from center to left or right. Participants were instructed to allocate their gaze as fast as possible to the target that appeared on the left or right side of the screen when the clip ended. One-third of the trials was valid (target in same location as stimulus gaze-shift), one-third invalid (target in opposite location of stimulus gaze-shift) and one-third catch (without target, thus without eye-movement response). The example stimulus shown here was adapted from the Pictures of Facial Affect database <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0031373#pone.0031373-Ekman1" target="_blank">[27]</a>.