Spatiotemporal Thermal Control Effects on Thermal Grill Illusion

The thermal grill illusion induces a pain sensation under a spatial display of warmth and coolness of approximately 40 degrees C; and 20 degrees C. To realize virtual pain display more universally during the virtual reality experience, we proposed a spatiotemporal control method to realize a variable thermal grill illusion and evaluated the effect of the method. First, we examined whether there was a change in the period until pain occurred due to the spatial temperature distribution of pre-warming and pre-cooling and verified whether the period until pain occurred became shorter as the temperature difference between pre-warming and pre-cooling increased. Next, we examined the effect of the number of grids on the illusion and verified the following facts. In terms of the pain area, the larger the thermal area, the larger the pain area. In terms of the magnitude of the pain, the larger the thermal area, the greater the magnitude of the sensation of pain.

Automated summary

The thermal grill illusion can induce a pain sensation under a spatial display of warmth and coolness at around 40 degrees Celsius and 20 degrees Celsius. In order to achieve a more universal virtual pain display during virtual reality experiences, a spatiotemporal control method was proposed to create a variable thermal grill illusion and its effectiveness was evaluated. The study examined the effects of spatial temperature distribution and grid size on the illusion, finding that increasing the temperature difference between warming and cooling shortened the time until pain occurred, and larger thermal areas resulted in larger pain areas and greater magnitude of pain sensation.