Universitätsklinikum Würzburg

Previous results from animal studies and translational research in humans show that the mere physical presence of a conspecific can reduce autonomic responses to aversive stimuli such as pain. Here we test the effect of social presence on the neural processing of approach-avoidance conflicts, i.e., in situations where aversive outcomes are weighed against potential rewards. Participants can choose to accept a twofold offer with independent probabilities for monetary rewards and painful stimulations, or to reject the offer, being safe from pain but also losing the chance of obtaining money. Importantly, they face these decisions either alone or in presence of another individual. Using ultra-high field (7T) functional magnetic resonance imaging (fMRI), we investigate the neural activity during the presentation of the conflict decisions (probabilities for money vs pain) and compare the respective effects between the alone and the social condition. We assume that social presence may buffer the aversive pain stimuli and thus increase approach behavior (accepting the offer for getting the chance to obtain money despite the risk of receiving pain). On the neural level, we predict activations in a network consisting of amygdala, dorsal anterior cingulate and periaqueductal gray, with stronger effects in the alone compared to the social condition. Preliminary results show that the approach-avoidance paradigm and the social manipulation have been successfully implemented in the 7T imaging environment. Our findings have the potential to reveal the neural approach-avoidance network with high spatial resolution and to provide novel insights into the social modulation of approach-avoidance conflicts.