On the Multimodality of Body Perception in Action

Recent research on proprioception reveals that it relies on a stored representation of bodily dimensions which is systematically distorted (Longo and Haggard, 2010; 2011). This generates a puzzle about the role of proprioception in action. On the one hand, action requires accurate bodily parameters to be successful; yet if proprioception relies on a systematically distorted model of bodily dimensions, then proprioceptive perception of limb position will contain systematic errors. This pushes us to jettison proprioception as a key source of parameters for motor control; yet the case of deafferented agents, who have no proprioception and touch in large parts of their body, suggests otherwise. In the absence of proprioception, ordinary action as we know it is impossible: deafferented agents have severe problems in the online control of action. The conjunction of these two claims presents a challenge to articulate the distinctive role of proprioception in action: for action as we know it, we cannot do without proprioception, but it is unclear why.