Somatic engagement alters subsequent neurobehavioral correlates of affective mentalizing

Socio-emotional encounters involve a resonance of others' affective states, known as affect sharing (AS); and attribution of mental states to others, known as theory-of-mind (ToM). Empathy necessitates the integration of both processes, yet their interaction during emotional episodes and subsequent generation of inferences on others' affective states has rarely been tested. To address this, we developed a novel experimental design, wherein we manipulated AS by presenting nonverbal emotionally negative movies twice-each time accompanied by one of two soundtracks that accentuated either somatic cues or externally generated sounds. Movies were followed by questions addressing affective-ToM (emotional inferences), cognitive-ToM (inferences on beliefs and knowledge), and non-ToM aspects. Results revealed a neural differentiation between AS, affective-ToM, and cognitive-ToM. AS movies activated regions that have been implicated in emotional (e.g., amygdala) and somatosensory processing, and synchronized brain activity between participants in the latter. Affective-ToM activated the middle insula, limbic regions, and both ventral and dorsal portions of the medial prefrontal cortex (ventral medial prefrontal cortex [VMPFC] and dorsal medial prefrontal cortex [DMPFC], respectively), whereas cognitive-ToM activated posteromedial and lateral-prefrontal and temporal cortices. Critically, AS movies specifically altered neural activation in AS and ToM-related regions during subsequent affective-ToM inferences, most notably in the DMPFC. Moreover, DMPFC-VMPFC connectivity correlated with affective-ToM accuracy, when such questions followed AS movies. Our results associate empathic processes with designated neural activations and shed light on how neuro-behavioral indices of affective ToM are shaped by preceding somatic engagement.