The perception of our body in space is flexible and manipulable. The predictive brain hypothesis explains this malleability as a consequence of the interplay between incoming sensory information and our body expectations. However, given the interaction between perception and action, we might also expect that actions would arise due to prediction errors, especially in conflicting situations. Here we describe a computational model, based on the free-energy principle, that forecasts involuntary movements in sensorimotor conflicts. We experimentally confirm those predictions in humans using a virtual reality rubber-hand illusion. Participants generated movements (forces) towards the virtual hand, regardless of its location with respect to the real arm, with little to no forces produced when the virtual hand overlaid their physical hand. The congruency of our model predictions and human observations indicates that the brain-body is generating actions to reduce the prediction error between the expected arm location and the new visual arm. This observed unconscious mechanism is an empirical validation of the perception-action duality in body adaptation to uncertain situations and evidence of the active component of predictive processing.

中文翻译：

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虚拟手错觉中多感官冲突抑制的主动策略

我们身体在空间中的感知是灵活和可操纵的。大脑预测假说将这种延展性解释为传入的感官信息与我们的身体期望之间相互作用的结果。然而，考虑到感知和行动之间的相互作用，我们也可能期望由于预测错误而产生行动，尤其是在冲突的情况下。在这里，我们描述了一个基于自由能原理的计算模型，该模型预测感觉运动冲突中的不自主运动。我们使用虚拟现实的橡皮手错觉通过实验证实了人类的这些预测。参与者向虚拟手产生运动（力），无论其相对于真实手臂的位置如何，当虚拟手覆盖他们的物理手时几乎没有产生力。我们的模型预测和人类观察的一致性表明，大脑-身体正在产生动作以减少预期手臂位置和新视觉手臂之间的预测误差。这种观察到的无意识机制是对身体适应不确定情况的感知-动作二元性的实证验证，也是预测处理的主动成分的证据。