Changes in cerebral blood flow during forward and backward walking with speed misperception generated by virtual reality

[Purpose] The purpose of this study was to investigate the effect of speed misperception on brain activity, created by a speed difference between actual walking and virtual reality walking videos. [Participants and Methods] The participants were 20 healthy young people. The walking speed in the video was set to 3 km/h to induce an error, while the actual walking speed was 1 km/h. Cerebral blood flow was measured using an optical imaging brain function measurement device. Left and right prefrontal cortices were analyzed using two channels and oxyhemoglobin level change from rest was used as a cerebral blood flow index. A t-test compared the cerebral blood flow dynamics before, during, and after the virtual reality video viewing under forward and backward walking conditions. [Results] Regarding changes in oxyhemoglobin levels during walking after watching the virtual reality video, cerebral blood flow increased especially in the backward walking state, where the difference was large in the right prefrontal cortex. [Conclusion] The backward walking that caused misperception by virtual reality is an extraordinary movement compared to forward walking. Thus, it is necessary to voluntarily adjust the movement by the cerebral cortex, and it is thought that activation of the prefrontal cortex occurs.