Effective connectivity reveals distinctive patterns in response to others' genuine affective experience of disgust

Parietofrontal Networks Mediate Contextual Influences in the Appraisal of Pain and Disgust Facial Expressions

We appraise other people's emotions by combining multiple sources of information, including somatic facial/body reactions and the surrounding context. Wealthy literature revealed how people take into account contextual information in the interpretation of facial expressions, but the mechanisms mediating such influence still need to be duly investigated. Across two experiments, we mapped the neural representations of distinct (but comparably unpleasant) negative states, pain, and disgust, as conveyed by naturalistic facial expressions or contextual sentences. Negative expressions led to shared activity in the fusiform gyrus and superior temporal sulcus. Instead, pain contexts recruited the supramarginal, postcentral, and insular cortex, whereas disgust contexts triggered the temporoparietal cortex and hippocampus/amygdala. When pairing the two sources of information together, we found a higher likelihood of classifying an expression according to the sentence preceding it. Furthermore, networks specifically involved in processing contexts were re-enacted whenever a face followed said context. Finally, the perigenual medial prefrontal cortex (mPFC) showed increased activity for consistent (vs inconsistent) face-context pairings, suggesting that it integrates state-specific information from the two sources. Overall, our study reveals the heterogeneous nature of face-context information integration, which operates both according to a state-general and state-specific principle, with the latter mediated by the perigenual medial prefrontal cortex.

Insula uses overlapping codes for emotion in self and others

In daily life, we must recognize others' emotions so we can respond appropriately. This ability may rely, at least in part, on neural responses similar to those associated with our own emotions. We hypothesized that the insula, a cortical region near the junction of the temporal, parietal, and frontal lobes, may play a key role in this process. We recorded local field potential (LFP) activity in human neurosurgical patients performing two tasks, one focused on identifying their own emotional response and one on identifying facial emotional responses in others. We found matching patterns of gamma- and high-gamma band activity for the two tasks in the insula. Three other regions (MTL, ACC, and OFC) clearly encoded both self- and other-emotions, but used orthogonal activity patterns to do so. These results support the hypothesis that the insula plays a particularly important role in mediating between experienced vs. observed emotions.

Preoperative plasticity in the functional naming network of patients with left insular gliomas

Plasticity could take place as a compensatory process following brain glioma growth. Only a few studies specifically explored plasticity in patients affected by a glioma invading the left insula; even more, plasticity of the insular cortex in task-based functional language network is almost unexplored. In the current study, we explored potential plasticity in a consecutive series of 22 patients affected by a glioma centered to the left insula, by comparing their preoperative object-naming functional network with that of a group of healthy controls. After having controlled for demographic variables, fMRI results showed that patients vs. controls activated a cluster in the right, contralesional pars triangularis including the Broca's area. On the other hand, controls did not significantly activate any brain region more than patients. At behavioral level, patients retained a generally preserved naming performance as well as a proficient language processing profile. These findings suggest that involvement of language-specific areas in the healthy hemisphere could help compensate for the left, affected insula, thus allowing preservation of the naming functions. Results are commented in relation to lesion site, naming performance, and potential relevance for neurosurgery.