Exploratory study of psychophysiological mechanism for a feeling of strangeness

2023 Fiscal Year Final Research Report

• Project/Area Number: 18K12022
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 90030:Cognitive science-related
• Research Institution: Komazawa University (2019-2023); Hiroshima International University (2018)
• Principal Investigator: Iwaki Tatsuya 駒澤大学, 文学部, 教授 (70341229)
• Co-Investigator(Kenkyū-buntansha): 大窪 伸太郎 広島国際大学, 総合リハビリテーション学部, 講師 (00805682)
• Project Period (FY): 2018-04-01 – 2024-03-31
• Keywords: 違和感 / 身体所有感 / ラバーハンド錯覚 / 視覚的違和感 / 表情制御 / 脳波活動

Outline of Final Research Achievements

In the present study, physical discomfort was defined and investigated as a feeling that occurs when the input visual and tactile information of the body is inconsistent with the internal model. In Experiment 1, EEG microstate analysis was conducted on the discomfort associated with the rubber hand illusion. In Experiment 2, participants were asked to judge whether the presented image was their own hand, someone else's hand or a prosthetic hand, using their own hand, someone else's hand or a prosthetic hand as the stimulus image. Event-related potentials associated with stimulus discrimination were analyzed. In Experiment 3, the task of making facial expressions that matched or mismatched the evoked emotional state was performed, and the discomfort of the facial expressions was examined. Throughout the experiment, discomfort was considered to involve the right frontal region in body-cognitive processing.

Free Research Field

生理心理学

Academic Significance and Societal Importance of the Research Achievements

違和感は人が何かいつもと違うと感じる感覚である。身体的違和感は、普段の身体感覚と異なる信号の検出を反映している。今回の一連の実験により、身体的違和感は脳の右前頭部の活動を伴う身体認知過程において生じることが分かった。これらの結果は身体的違和感を評価するための基礎資料の蓄積に貢献できた。今後、違和感を客観評価できるようになると、自身に起こっている身体的異変の評価や、多くの人工物とのインターフェース部で生じる感覚を評価できるので、多方面への応用展開に結びつくと思われる。