Altered functional connectivity of the hippocampus with the sensorimotor cortex induced by long-term experience of virtual hand illusion

Synchronizing the movement of a virtual hand with an unseen real hand in a virtual environment is an effective method to induce a sense of ownership of the virtual hand. Although several neuroimaging studies have revealed neural mechanisms related to the ongoing process of ownership illusion, the effect of the long-term experience of ownership illusion on brain activity remains to be investigated. Here, we developed an apparatus based on real-time image matting and virtual reality technology which allowed us to use the image of participants’ real hands as their virtual hands and synchronize the movement of the virtual hands with the unseen real hands in a virtual scene. Resting-state functional imaging data were acquired immediately after participants completed several light office tasks with the virtual hands in either the virtual environment (virtual hand condition) or real environment (real hand condition). Significant positive functional connectivity of the hippocampus with the primary somatosensory and motor cortex was only observed in the virtual hand condition. The results provided novel evidence for the involvement of hippocampal-sensorimotor connection in the long-term experience of virtual hand ownership. The functional connection reorganization of the hippocampus might promote multi-sensory information integration into memory and updated the sense of body ownership, which offered important insights into the neural network underlying the availability of long-term use of VR technology in healthcare and rehabilitation.