Frisco Francesca, Daneyko Olga, Maravita Angelo, Zavagno Daniele
Department of Psychology, University of Milan-Bicocca.
Department of Psychology, Sociology and Politics, Sheffield Hallam University.
J Exp Psychol Hum Percept Perform. 2023 Sep;49(9):1271-1279. doi: 10.1037/xhp0001144. Epub 2023 Jul 6.
The role of arm posture in the Uznadze haptic aftereffect is investigated: two identical test stimuli (i.e., spheres, TS) clenched simultaneously appear haptically different in size after hands have been adapted to two spheres (adapting stimuli, AS) differing in size: the hand adapted to a small AS feels TS bigger than the hand adapted to a big AS. In two experiments, participants evaluated the haptic impressions of two TS after adaptation by finding their match on a visual scale. In Experiment 1, all tasks were carried out with arms either uncrossed or crossed. In Experiment 2, only the matching task was performed with arms either uncrossed or crossed while adaptation was conducted by continuously changing arm posture from uncrossed to crossed and vice versa. The illusion occurred irrespectively of arm posture; however, its magnitude was smaller when adaptation was carried out in the classical condition of uncrossed arms. Results are discussed in light of two functional mechanisms: low-level somatotopic mapping (i.e., stimuli conformation) and high-level level factors (i.e., arm posture) that could modulate the haptic perception. (PsycInfo Database Record (c) 2025 APA, all rights reserved).
在双手适应了两个大小不同的球体（适应刺激，AS）之后，同时握紧的两个相同测试刺激（即球体，TS）在触觉上会显得大小不同：适应小AS的手会觉得TS比适应大AS的手更大。在两个实验中，参与者通过在视觉量表上找到匹配项来评估适应后两个TS的触觉印象。在实验1中，所有任务都是在手臂不交叉或交叉的情况下进行的。在实验2中，只有匹配任务是在手臂不交叉或交叉的情况下进行的，而适应过程是通过不断改变手臂姿势，从不交叉到交叉，反之亦然。无论手臂姿势如何，错觉都会出现；然而，当在手臂不交叉的经典条件下进行适应时，错觉的程度较小。根据两种功能机制对结果进行了讨论：低级躯体定位映射（即刺激构象）和可能调节触觉感知的高级因素（即手臂姿势）。（PsycInfo数据库记录（c）2025美国心理学会，保留所有权利）
