Brain activity and prosocial behaviour in a simulated life-threatening situation

Recent studies in social neuroscience have begun identifying the brain areas involved in the interactions among human beings, in other words, social interactions. This work is aimed to investigate social behaviours in a simulated life-threatening situation and the patterns of brain areas recruited in subjects that exhibit either a self-benefit behaviour or an altruistic one. Forty-three subjects were evaluated in a computer-based environment that simulates an emergency situation in which they had to evacuate a building on fire. Toward the end, without being previously informed, participants encountered a trapped humanoid, asking for help. Each subject was therefore faced with the dilemma of helping or not it, at the possible cost of his own life. Blood-oxygen-level-dependent (BOLD) functional images were obtained and group independent component analysis (gICA) was performed to identify spatially independent source of signal. Several brain-related ICs were identified. Sensory and motor ICs included activations in the primary motor and premotor cortices, in the auditory cortex and in the occipital pole. Spatially segregated activity was also observed in the default-mode network, the insula, the anterior cingulate cortex (ACC) and the medial prefrontal cortex (mPFC). Interestingly, activity in auditory-processing areas, ACC and mPFC was strictly related with the encounter of the humanoid, suggesting a critical role in deciding about saving or not the humanoid. In conclusion, gICA allowed to highlight different patterns of neuronal activity in a highly ecological life-threatening situation by means of virtual reality. The study opens new avenues to the investigation of complex social interactions.