Final Activity Report Summary - NEUROEMPATHY (Towards a neuroscience of empathy: shared circuits for actions, emotions and sensations) While we view a Hollywood movie, we effortlessly feel the goals of the actors, we live with their emotions and share their sensations. How does that happen?ActionsParticipants were scanned while hearing the actions of others and performing similar actions. The sound of hand actions recruited parts of the premotor and parietal cortex also involved in performing hand actions and the sound of mouth actions also activates those involved in performing mouth actions. The pattern of activity in premotor and parietal cortex allows to discriminate if a sound was of a hand or a mouth action using the same rule that could discriminate whether an executed action was of the hand or the mouth. More empathic individuals activate their own actions more strongly while listening to those of others. While we witness the actions of others, we activate motor programs we would use to achieve similar goals (e.g. picking up a cup), even if they differ from those seen. These vicarious activations of motor cortex are involved in coordinating our actions with those of others.EmotionsWhen participants view the disgust, pleasure or fear of others, they activate regions of the insula also involved in feeling similar bodily states and regions of the premotor and somatosensory cortex involved in generating similar facial expressions. These effects are stronger in more empathic individuals. Even reading about emotions triggers activity in the same region. We therefore also share the emotions of others in our emotional brain regions. SensationsBA2, the highest processing level of SI, integrating proprioceptive and tactile information is consistently recruited both while participants view hand actions and execute similar hand actions. The pattern of activity in SI during action perception contains information about what action other people perform. Processing the actions of others therefore also involves somatosensory cortices. Interfering with SI impairs the capacity to judge the actions of others (in prep)Witnessing pleasant, neutral and painful interactions between people recruits dinstinguishable patterns of activity in somatosensory and insular cortices, supporting the idea that vicarious somatosensory activity caries information about valence. With the group of Dan Tranel in Iowa (USA) we check if lesions in SI or SII impair judging what other people feel (ongoing).ConnectionsWe could show that the insula has a continuous pattern of connectivity and that viewing the emotions of others activity is first triggeres vicarious activity in the motor system which then triggers activity in emotional cortices. Finally, while two people gesture to each other, the activity in the motor system of the gesturer triggers activity in both the motor and mentalising system of the observer. This suggests that mentalising brain regions and the shared circuits we have demonstrated interact to understand what goes on in other people and provides a new method to study social interactions.Psychiatric DisordersWhile viewing the emotions of others, activity in shared circuits is reduced in the motor, emotional and somatosensory cortices of patients with predominantly negative symptoms and schizophrenia. In autism, such activity is only reduced early in life, and normalises by about 30years. Accelerating this normalisation might be a promising target for therapies.Unifying PrincipleA single principle, that of activating cortices that deal with our own states while viewing those of others, therefore applies to: 3 types of cortices (motor, emotional and somatosensory), 3 modalities (viewing, hearing and reading) and can account for much of the differences in empathy in the general population and in psychiatric disorders. This unifying principle can explain why viewing movies or the states of other people is so engaging: our brain makes us experience similar motor, emotional and somatosensory states. People with less such vicarious activity will be less empathic or suffer from social disorders.
