Inducing Bodily Resizing Illusions Through Embodied Actions in Virtual Reality

2024 Fiscal Year Final Research Report

• Project/Area Number: 22K17940
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 61020:Human interface and interaction-related
• Research Institution: The University of Tokushima (2024); Kanazawa Institute of Technology (2022-2023)
• Principal Investigator: ISHIHARA Yuki 徳島大学, 大学院社会産業理工学研究部(社会総合科学域), 講師 (40938065)
• Project Period (FY): 2022-04-01 – 2025-03-31
• Keywords: 身体イメージ / 身体所有感 / VR / 行為主体感 / 錯覚

Outline of Final Research Achievements

This study investigated the intensity of finger resizing illusions under various conditions that incorporated gestures evocative of finger stretching and action-based intentionality. The results demonstrated that the condition involving the direct pulling of one’s own finger elicited the strongest illusion. Although the illusion induced by the gesture combined with intentional movement was somewhat weaker, it remained substantially stronger than those observed in the other conditions. Based on these findings, we developed an application that allows users to experience the finger resizing illusion independently and to assess their perceived pain levels.
Furthermore, extending the focus from individual fingers to the entire body, we constructed a stretching environment that enhances the sensation of bodily elongation by synchronizing visual feedback with the muscle extension associated with users’ stretching movements.

Free Research Field

ヒューマンインターフェース

Academic Significance and Societal Importance of the Research Achievements

本研究により，単に視覚的に指が伸縮する様子を眺めるよりも，体験者自身が能動的に指を伸ばそうとするジェスチャーを取った場合の方が，効果的に指の伸縮感を得られることが示された．これはセルフケアとしての疼痛リハビリテーションに寄与する他，VR空間内のアバタ形状の新しいカスタマイズ手法としての活用も期待できる．また，直接的に身体イメージを変調させる手でなく，もう一方の手による能動的動作が，錯覚強度に影響を及ぼすことを確認できたことは，認知科学的観点からも意義深い研究である．
また全身のストレッチング動作による錯覚手法の開発は，腰痛等のより広い疼痛部位へと適用できるシステムにつながることが期待される．