Effects of Modulation of Cortical Activity on Two-point Discrimination Sensation in Accordance with Individual Characteristics of Brain Rhythm

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K19429
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 59010:Rehabilitation science-related
• Research Institution: Niigata University of Health and Welfare
• Principal Investigator: Yokota Hirotake 新潟医療福祉大学, リハビリテーション学部, 助教 (20827472)
• Project Period (FY): 2020-04-01 – 2022-03-31
• Keywords: 二点識別覚 / α律動 / 経頭蓋交流電流刺激 / 左後頭頂皮質 / 一次体性感覚野

Outline of Final Research Achievements

Brain rhythms in the alpha band (8-13 Hz) are known to influence perception, but the effects of changes in alpha band activity in the left posterior parietal cortex (PPC) and primary somatosensory cortex (S1), which have been suggested to play different roles for a higher-order perceptual measure, two-point discrimination (TPD), on TPD threshold are unknown .
We stimulated the left PPC and S1 using 10 Hz transcranial alternating current stimulation (tACS), which can noninvasively modulate brain rhythms, in 17 healthy students and measured TPD threshold in the right index finger. The results demonstrated that tACS lowered TPD threshold when applied over the left PPC but did not change it when applied over left S1, demonstrating a region-specific effect on TPD threshold determination.

Free Research Field

神経生理学

Academic Significance and Societal Importance of the Research Achievements

本研究によりtACSを用いて感覚皮質の可塑的変化を誘導することで二点識別覚（TPD）の向上が得られることが明らかとなった．将来的に慢性疼痛患者の痛覚知覚との関連を明らかにできれば，これまで効果が限定的であった慢性疼痛における新たな治療法開発につながることが期待できる．さらに，対象部位を変えれば，脳律動の関与が指摘される認知機能や運動機能の低下などに対しても汎用の可能性があり，様々な領域の障害回復に応用できる可能性がある．