VR-induced interoceptive feedback may impact tactile priority in individuals with low interoceptive awareness

Neglect-like symptoms on the affected side of the body have gained attention in patients with chronic pain, and these symptoms may increase pain. One of the neglect-like symptoms on the affected side is that when stimulation is applied to both hands, there is a delay in noticing information from the affected hand (the priority of tactile sensation from the affected hand decreases). Thus, an intervention that can modulate tactile priority may be useful. Recently, the visual feedback of interoception, such as heartbeat, has been shown to be potentially effective in modulating body priorities. Therefore, in the present study, we tested whether the prioritization of tactile information could be improved by providing interoceptive feedback to the hand of a specific side (left side) using a virtual reality (VR) system. The feedback conditions were as follows: a group with feedback from a flashing signal synchronized with the self’s heartbeat (Syn group), a group with feedback from a flashing signal unrelated to the self’s heartbeat (Asyn group), and a group with no feedback (CTR group). A temporal order judgment task was used to assess changes in tactile priority for the feedback side of the hand. In addition, we examined whether individual interoceptive accuracy (IAcc) influenced changes in tactile priority. Our results did not show significant changes in tactile priority under any of the three feedback conditions. However, in the Syn group, we found a significant negative correlation between changes in tactile priority and the IAcc. These results indicate that interoceptive feedback might be effective for participants with a lower IAcc. The clinical significance of these results is also discussed.