A fronto-parietal network for chewing of gum: a study on human subjects with functional magnetic resonance imaging

The purpose of this study is to investigate human brain activity during mastication using fMRI. Twelve right-handed normal subjects performed two tasks: chewing of gum at their own pace, and imitating the movements of chewing gum. In order to reveal which areas of the brain are more strongly activated while chewing gum, we performed the conjunction analyses of gum chewing minus sham chewing with gum chewing minus rest. The common activity in the orofacial sensorimotor and premotor cortex was subtracted out since it was common to both tasks, but there were some differences in activity in some prefrontal and posterior parietal cortex areas. Our results suggest that a fronto-parietal network for mastication exists and may contribute to higher cognitive information processing.