March 3, 2021
Nagoya University
Keio University
A research group, including Professor Satoshi Umeda and Associate Professor Yuri Terasawa from the Psychology Laboratory, Faculty of Letters, Keio University, and Associate Professor Kazuya Motomura from the Department of Neurosurgery, Graduate School of Medical Sciences, Nagoya University, conducted tests on emotional recognition ability in brain tumor patients before and after resection surgery. They revealed that a decline in this ability is associated with a decrease in the ability to perceive changes in the body's internal state (interoception).
While various studies have advanced our understanding of the relationship between brain and mind functions, the answer to how the recognition of one's own emotions—such as happiness, sadness, or anger—changes when a specific brain region is damaged or resected remains unknown. Previous research has shown that stimulation or resection of the insular cortex (insula), which is deeply related to the perception of changes in internal bodily states like heartbeat and respiration, can alter the recognition of excitatory emotions such as anger, but the reason for this has not been clear.
In this study, 18 patients with brain tumors involving the insula underwent a facial expression recognition task (a task to recognize expressions from photographs) and a task to measure interoception before and after resection surgery. A comparison of the test results from both tasks before and after surgery revealed a statistically significant association between a decline in the ability to recognize emotions such as anger and joy and a decline in interoception. This indicates that the insular cortex functions as the neural basis for interoception, which is information from within the body, and supports the recognition of emotions like anger and joy. It also suggests that bodily sensations, such as a racing heart or restlessness, are essential for experiencing rich emotions. The results of this study suggest that traumatic or age-related changes in the peri-insular region may also alter how emotions are felt.
The results of this research were published in the online edition of the international scientific journal "Cortex" (April 2021 issue).
This research was supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI Grant-in-Aid for Scientific Research (B) (No. 24330210) and Grant-in-Aid for Scientific Research (C) (No. 25861268).
For the full press release, please see below.