The sense of body ownership represents a fundamental aspect of our self-awareness, but is disrupted in many neurological, psychiatric, and psychological conditions that are also characterized by disruption of skin temperature regulation, sometimes in a single limb. We hypothesized that skin temperature in a specific limb could be disrupted by psychologically disrupting the sense of ownership of that limb. In six separate experiments, and by using an established protocol to induce the rubber hand illusion, we demonstrate that skin temperature of the real hand decreases when we take ownership of an artificial counterpart. The decrease in skin temperature is limb-specific: it does not occur in the unstimulated hand, nor in the ipsilateral foot. The effect is not evoked by tactile or visual input per se , nor by simultaneous tactile and visual input per se , nor by a shift in attention toward the experimental side or limb. In fact, taking ownership of an artificial hand slows tactile processing of information from the real hand, which is also observed in patients who demonstrate body disownership after stroke. These findings of psychologically induced limb-specific disruption of temperature regulation provide the first evidence that: taking ownership of an artificial body part has consequences for the real body part; that the awareness of our physical self and the physiological regulation of self are closely linked in a top-down manner; and that cognitive processes that disrupt the sense of body ownership may in turn disrupt temperature regulation in numerous states characterized by both.

Complex regional pain syndrome (CRPS) occurs after stroke, but most cases develop after peripheral trauma and without evidence of brain trauma. However, CRPS is associated with symptoms that appear similar to those observed in patients suffering from hemispatial neglect. Ten participants (four males) with CRPS of one arm performed temporal order judgements of pairs of vibrotactile stimuli, one delivered to each hand, at one of 10 possible stimulus onset asynchronies, under two conditions: arms held each side of the midline and arms crossed over the midline. Participants released a foot switch to indicate which hand had been stimulated first. The order of conditions was randomized and the foot under which the switch was positioned was counterbalanced. There were two blocks of 150 trials in each condition. The stimulus onset asynchronicity at which the participants were equally likely to select either hand, the point of subjective simultaneity (PSS), was compared between conditions and between those with left or right-sided symptoms. When arms were not crossed, the participants prioritized stimuli from the unaffected limb over those from the affected limb (mean ± SD PSS = 25 ± 7.5 ms) and the magnitude of the PSS strongly related to the degree to which the affected hand was cooler than the unaffected hand (r = 0.942, P < 0.001). When the arms were crossed, the effect was reversed: the participants prioritized stimuli from the affected limb over those from the unaffected limb [PSS = –18 ± 13 ms; main effect of condition F (1, 9) = 98.6, P < 0.001]. There was no effect of the side of symptoms. These results show that CRPS is associated with a deficit in tactile processing that is defined by the space in which the affected limb normally resides, not by the affected limb itself, and which relates to the relative cooling of the affected limb. This pattern is consistent with data from those with hemispatial neglect after stroke and raises the possibility that chronic CRPS involves a type of spatial neglect.