Lush P, Seth A K, Dienes Z
Sackler Centre for Consciousness Science, University of Sussex, Falmer, BN1 9RH, UK.
Department of Informatics, University of Sussex, Chichester Building, Falmer, BN1 9RH, UK.
R Soc Open Sci. 2021 Nov 3;8(11):210911. doi: 10.1098/rsos.210911. eCollection 2021 Nov.
Reports of changes in experiences of body location and ownership following synchronous tactile and visual stimulation of fake and real hands (rubber hand (RH) effects) are widely attributed to multisensory integration mechanisms. However, existing control methods for subjective report measures (asynchronous stroking and control statements) are confounded by participant hypothesis awareness; the report may reflect response to demand characteristics. Subjective report is often accompanied by indirect (also called 'objective' or 'implicit') measures. Here, we report tests of expectancies for synchronous 'illusion' and asynchronous 'control' conditions across two pre-registered studies ( = 140 and = 45) for two indirect measures: proprioceptive drift (a change in perceived hand location) and skin conductance response (a measure of physiological arousal). Expectancies for synchronous condition measures were greater than for asynchronous conditions in both studies. Differences between synchronous and asynchronous control condition measures are therefore confounded by hypothesis awareness. This means indirect measures of RH effects may reflect compliance, bias and phenomenological control in response to demand characteristics, just as for subjective measures. Valid control measures are required to support claims of a role of multisensory integration for both direct and indirect measures of RH effects.
关于在对假手和真手进行同步触觉和视觉刺激后身体位置和所有权体验变化的报告（橡胶手效应）被广泛归因于多感官整合机制。然而，现有的主观报告测量控制方法（异步抚摸和控制语句）因参与者的假设意识而混淆；报告可能反映了对需求特征的反应。主观报告通常伴随着间接（也称为“客观”或“隐性”）测量。在此，我们报告了在两项预先注册的研究（N = 140和N = 45）中针对两种间接测量方法（本体感觉漂移（手部位置感知的变化）和皮肤电导反应（生理唤醒的一种测量））对同步“错觉”和异步“控制”条件预期的测试。在两项研究中，同步条件测量的预期均高于异步条件。因此，同步和异步控制条件测量之间的差异因假设意识而混淆。这意味着橡胶手效应的间接测量可能反映了对需求特征的顺应、偏差和现象学控制，就像主观测量一样。需要有效的控制方法来支持关于多感官整合在橡胶手效应直接和间接测量中作用的主张。
