Cortical Activation Accompanying Mastication, Swallowing, and Motor Imagery : Spectral Analysis of Electroencephalogram

2001 Fiscal Year Final Research Report Summary

• Project/Area Number: 12671905
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 補綴理工系歯学
• Research Institution: Nihon University
• Principal Investigator: NARITA Noriyuki Nihon University, School of Dentistry at Matsudo, Associate Professor, 松戸歯学部, 助教授 (10155997)
• Project Period (FY): 2000 – 2001
• Keywords: EEG / mastication / swallowing / motor imagery / spectral analysis / TMD

Research Abstract

The cortical activity was investigated using spectral analysis of electroencephalogram (EEG) to clarify the cortical activation accompanying mastication, swallowing, and motor imagery of mastication and swallowing. The EEG was recorded using a 19-channel EEG system (SYNAFIT 2500, NEC Co).
1. Cortical activation accompanying mastication : brain activation by mastication could be expressed as the relaxed wakefulness with some intense mental activity from the topographical aspects of EEG spectrum, also food intake could be related to the mental intense for the preparation of masticatory performance.
2. Cortical activation accompanying masticatory duration : brain activation could be affected by the duration of mastication based on the topographical aspects of EEG spectra, such as the appearance of theta and/or delta waves.
3. Cortical activation accompanying food hardness on mastication : cortical activation could be affected by food textures such as hardness, which is expressed by the appea rances of alpha and beta waves and disappearance of theta and/or delta wave.
4. Cortical activation accompanying masticatory imagery : brain activation shown by masticatory imagery could be described as typical relaxed wakefulness without intense mental activity in the frontal cortex area based on EEG spectra.
5. Cortical activation accompanying swallowing : in comparing spectral wave factors of EEG between pre- and post- swallowing, the beta 1, the beta 2, and delta waves were significantly increased in the post-swallowing phase. Therefore, it is assumed that cortical activation by swallowing could be described as intense mental activity based on the topographical aspects of EEG spectra.
6. Cortical activation accompanying swallowing imagery : brain activation in accordance with swallowing imagery could be described as typical of relaxed wakefulness without intense mental activity based on the topographical aspects of EEG spectra.
7. The effect of mastication to cortical activation in TMDs : TMDs lack the cortical activation shown by the increases in alpha and beta wave factors and decrease in theta wave factor which presented in the frontal area of normal subjects. This may be related to modification of masticatory motor behaviors.
From the above results, it is concluded that EEG spectra could be indicated peculiar topographical findings according to the aspects of mastication, swallowing and motor imagery of mastication and swallowing, and further modification of EEG spectra could be indicated in TMDs.