(How) observed eye-contact modulates gaze following. An fMRI study

Humans are highly sensitive to directional gaze cues and rapidly shift attention in accordance with others' gaze (i.e., gaze following). Besides providing information about the physical environment, for instance, the location of an object, gaze direction can be used to extract information about the social environment, such as whether or not two people are interacting with each other. In the present fMRI study we investigated how these two different types of information conveyed by gaze direction interact with one another. Participants saw two faces that were either looking at each other or away from each other before jointly shifting gaze toward one of two target locations. Targets either appeared at the gazed at or the non-gazed at location. Behaviorally, gaze following (faster responses to congruent versus incongruent trials) was more prominent after observing eye contact than after observing no eye contact. In line with behavioral findings, neuroimaging results revealed enhanced activation in fronto-parietal and temporal areas in congruent trials when faces had looked at each other versus away from each other. These findings demonstrate that observing an attentional relation between others augments processing of their subsequent gaze cues.