Since the pioneering work of Penfield and his colleagues in the 1930s, the somatosensory cortex, which is located on the postcentral gyrus, has been known for its central role in processing sensory information from various parts of the body. More recently, a converging body of literature has shown that the somatosensory cortex also plays an important role in each stage of emotional processing, including identification of emotional significance in a stimulus, generation of emotional states, and regulation of emotion. Importantly, studies conducted in individuals suffering from mental disorders associated with abnormal emotional regulation, such as major depression, bipolar disorder, schizophrenia, post-traumatic stress disorder, anxiety and panic disorders, specific phobia, obesity, and obsessive-compulsive disorder, have found structural and functional changes in the somatosensory cortex. Common observations in the somatosensory cortices of individuals with mood disorders include alterations in gray matter volume, cortical thickness, abnormal functional connectivity with other brain regions, and changes in metabolic rates. These findings support the hypothesis that the somatosensory cortex may be a treatment target for certain mental disorders. In this review, we discuss the anatomy, connectivity, and functions of the somatosensory cortex, with a focus on its role in emotional regulation.

Stability of the DMN, FPN and SN may reflect a state of remission. Further, DMN hypoconnectivity may reflect a positive history of psychosis in patients with bipolar disorder compared with controls, highlighting a potentially different neural phenotype of psychosis in people with bipolar disorder. Resting-state functional connectivity changes between the amygdala, prefrontal cortex and cingulate cortex may reflect a neural correlate of subthreshold symptoms experienced in bipolar disorder euthymia, the trait-based pathophysiology of bipolar disorder and/or a compensatory mechanism to maintain a state of euthymia.