title: Effects of chewing in working memory processing.
abstract: It has been generally suggested that chewing produces an enhancing effect on cognitive performance-related aspects of memory by the test battery. Furthermore, recent studies have shown that chewing is associated with activation of various brain regions, including the prefrontal cortex. However, little is known about the relation between cognitive performances affected by chewing and the neuronal activity in specified regions in the brain. We therefore examined the effects of chewing on neuronal activities in the brain during a working memory task using fMRI. The subjects chewed gum, without odor and taste components, between continuously performed two- or three-back (n-back) working memory tasks. Chewing increased the BOLD signals in the middle frontal gyrus (Brodmann's areas 9 and 46) in the dorsolateral prefrontal cortex during the n-back tasks. Furthermore, there were more prominent activations in the right premotor cortex, precuneus, thalamus, hippocampus and inferior parietal lobe during the n-back tasks after the chewing trial. These results suggest that chewing may accelerate or recover the process of working memory besides inducing improvement in the arousal level by the chewing motion.
authors.affiliation: Department of Biophysics, Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan. hirano@nirs.go.jp
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Hirano
authors.forename: Takayuki
authors.initials: T
authors.lastname: Obata
authors.forename: Kenichi
authors.initials: K
authors.lastname: Kashikura
authors.forename: Hiroi
authors.initials: H
authors.lastname: Nonaka
authors.forename: Atsumichi
authors.initials: A
authors.lastname: Tachibana
authors.forename: Hiroo
authors.initials: H
authors.lastname: Ikehira
authors.forename: Minoru
authors.initials: M
authors.lastname: Onozuka
mesh_terms: D000328:Adult; D001921:Brain / Q000098:blood supply / Q000502:physiology*; D001931:Brain Mapping; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008409:Mastication / Q000502:physiology*; D008570:Memory, Short-Term / Q000502:physiology*; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood
chemical_list: D010100:Oxygen