Measurement of Brain Activity during Facial Self-touching by Near-infrared Spectroscopy

Abstract

Using near-infrared spectroscopy, the effect of facial self-touching on the prefrontal cortex activity was investigated by comparing the activations produced by the following conditions: 1) pressure applied to the cheeks (cheek-pressing) with bare hands, 2) cheek-pressing with hands wearing rubber groves, and 3) no touching. The results indicated that regions of the frontopolar cortex (FPC) and orbitofrontal cortex (OFC) were significantly activated only under condition 1 (cheek-pressing with bare hands). In addition, the standard scores (z-scores) for cerebral blood flow in the FPC and OFC were significantly correlated with the subjective scores for pleasant emotions. These results indicate that the FPC and OFC are related to pleasant emotions during self-touching. These findings are expected to be applied to the quantitative assessment of pleasant emotions during facial self-touching.