Immersive Interaction Research Group (IIG), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
Laboratory of Cognitive Neuroscience (LNCO), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
PLoS One. 2023 May 11;18(5):e0282967. doi: 10.1371/journal.pone.0282967. eCollection 2023.
The brain mechanism of embodiment in a virtual body has grown a scientific interest recently, with a particular focus on providing optimal virtual reality (VR) experiences. Disruptions from an embodied state to a less- or non-embodied state, denominated Breaks in Embodiment (BiE), are however rarely studied despite their importance for designing interactions in VR. Here we use electroencephalography (EEG) to monitor the brain's reaction to a BiE, and investigate how this reaction depends on previous embodiment conditions. The experimental protocol consisted of two sequential steps; an induction step where participants were either embodied or non-embodied in an avatar, and a monitoring step where, in some cases, participants saw the avatar's hand move while their hand remained still. Our results show the occurrence of error-related potentials linked to observation of the BiE event in the monitoring step. Importantly, this EEG signature shows amplified potentials following the non-embodied condition, which is indicative of an accumulation of errors across steps. These results provide neurophysiological indications on how progressive disruptions impact the expectation of embodiment for a virtual body.
最近，人们对虚拟身体体现的大脑机制产生了浓厚的科学兴趣，特别是在提供最佳虚拟现实 (VR) 体验方面。然而，尽管在 VR 交互设计中具有重要意义，但人们很少研究从体现状态到较少体现或非体现状态的中断，即体现中断 (BiE)。在这里，我们使用脑电图 (EEG) 来监测大脑对 BiE 的反应，并研究这种反应如何取决于先前的体现条件。实验方案包括两个连续的步骤；在诱导步骤中，参与者要么以化身体现，要么不体现，在监测步骤中，在某些情况下，参与者看到化身的手移动，而他们的手保持静止。我们的结果显示，在监测步骤中观察到 BiE 事件时，会出现与错误相关的电位。重要的是，这种 EEG 特征在非体现状态后显示出放大的电位，这表明在步骤之间积累了错误。这些结果提供了神经生理学上的迹象，表明渐进式中断如何影响对虚拟身体的体现期望。
