In the rubber hand illusion (RHI), participants report ownership of a fake hand which is stroked in synchrony with their own concealed hand, with lower ownership ratings for asynchronous stroking. This effect has been historically attributed to multisensory integration. However, such a pattern of results is consistent with experimental demand characteristics, and an alternative theory proposes that the RHI is an effect of phenomenological control (PC; the trait ability to change experience to satisfy goals). To date, support for a PC theory of the RHI has been limited to correlational evidence. Here we conduct a pre-registered causal test of the relative contribution of these two proposed mechanisms in RHI effects. XX high PC participants (top 10%) were tested in an RHI procedure and the classic effects of greater response for synchrony than asynchrony were/were not replicated. The procedure was then repeated following imaginative suggestions for a reversal of the classic effect (i.e. greater synchrony than asynchrony effects). Ratings of ownership and proprioceptive drift were/were not modulated by suggestion. Effects for ownership and drift were/were not reversed. PC does/does not dominate over multisensory mechanisms in RHI ownership of a fake hand and proprioceptive drift.
Lush et al. (Fri,) studied this question.