Neural origins of mind reading

ongoing

Human thoughts have no mass and remain definitely hidden from others’ view. Still, we are remarkable at predicting others’ mental states from observable phenomena. Sensitivity to eye cues enables us, for example, to detect the presence of other minds, assess theirs content and interact with them through eye contact, gaze following and joint attention. Emerging in early infancy, these competences are precursor to later mentalizing abilities and are known to depend upon a set of cerebral structures overlapping with the theory of mind network, under the regulatory influence of neuropeptides such as oxytocin. While the existence of theory of mind in monkeys and apes is a matter of debate, these animals attend to eyes and understand what others see. Non-human primates thus offer a valuable perspective on the evolutionary path that shaped our brain to use eyes as a social interaction device and as a window into other’s mind. SOCIALEYES will aim to test the hypothesis that “eye reading” is rooted in conserved visual specializations, shared with functions like threat and danger detection. It will emphasize the role of a subcortical network that includes the hypothalamic oxytocin system, superior colliculus and amygdala. The links between eye processing, joint attention and knowledge states attribution (WP1) will be investigated in socially-interacting monkey dyads. The contribution of the colliculus and amygdala to joint attention mechanisms will be compared to that of core mentalizing regions of the cortex (WP2) using single neuron recordings. The functional role of oxytocin signaling within this network on joint attention and eye reading behavior (WP3) will be evaluated with site- and cell type-specific reversible inactivation procedures. Finally, the relevance of joint attention and eye reading abilities to natural social interactions (WP4) will be tested using novel ethological and computer vision-based behavior recognition methods in freely behaving monkeys.