Neural correlates of social and nonsocial emotions: An fMRI study.
Common theories of emotion emphasize valence and arousal dimensions or alternatively, specific emotions, and the search for the underlying neurocircuitry is underway. However, it is likely that other important dimensions for emotional neurocircuitry exist, and one of them is sociality. A social dimension may code whether emotions are addressing an individual's biological/visceral need versus more remote social goals involving semantic meaning or intentionality. Thus, for practical purposes, social emotions may be distinguished from nonsocial emotions based in part on the presence of human forms. In the current fMRI study, we aimed to compare regional coding of the sociality dimension of emotion (nonsocial versus social) versus the valence dimension of emotion (positive versus negative). Using a novel fMRI paradigm, film and picture stimuli were combined to induce and maintain four emotions varying along social and valence dimensions. Nonsocial emotions of positively valenced appetite and negatively valenced disgust and social emotions of positively valenced joy/amusement and negatively valenced sadness were studied. All conditions activated the thalamus. Appetite and disgust activated posterior insula and visual cortex, whereas joy/amusement and sadness activated extended amygdala, superior temporal gyrus, hippocampus, and posterior cingulate. Activations within the anterior cingulate, nucleus accumbens, orbitofrontal cortex, and amygdala were modulated by both social and valence dimensions. Overall, these findings highlight that sociality has a key role in processing emotional valence, which may have implications for patient populations with social and emotional deficits.