In order to navigate in a complex, dynamic social environment, humans need efficient communication mechanisms. In addition to vocal signals, we are experts in the analysis and exchange of visual information. Body, head and gaze orientation provide information about an individual depending on its status, affect and intentions thanks to the different non-verbal interactions we engage in. An telling example of how such cues can also be used by non-human primates has been captured by the video surveillance system of our housing facility.
Communication mediated by social gaze has a dual function: on the one hand, it is essential for reading the behavior of other individuals, and on the other hand, it is a powerful tool to communicate information about oneself. As these two functions can often not be accomplished independently from one another, eye movements need to be finely controlled to avoid the risk, for example, that gazing at someone to assess the direction of their attention will lead to a prolonged eye contact experienced as intrusive. Despite its importance in the behavioral repertoire of primates, the neural substrates that support social gaze remain elusive. Using live face-to-face interactions, we confirmed the existence of eye contact detecting neurons (Mosher et al., Curr Biol 2014) and further found that some amygdala neurons discharge in conjunction with the active interruption of mutual gaze. Thus, the amygdala may be involved in the regulation of social gaze, i.e. not only coding the direction of other’s gaze but also in the decision to engage in or disengage from eye contact (Gilardeau et al., Neuropsychologia 2021).