Thermal Masking: When the Illusion Takes Over the Real

This paper reports on a thermal illusion called thermal masking. Thermal masking is a phenomenon induced by thermal referral to completely mask the original thermal sensation, providing thermal sensation only at the tactile site. Three experiments are conducted using thermal and vibrotactile actuators to investigate the nature of thermal masking on human arms. The first experiment investigates the effects of different temperatures on masking. The results show a higher percentage of thermal masking occurs in warm than hot or cold conditions. The second experiment examines how far the thermal masking can be perceived. The results show that masking can reach up to 24 cm from the thermal site. The third experiment explores the interaction space by placing the tactile actuators on the opposite side of the thermal actuator. The results confirm that thermal masking can reach the other side of the arm, and the performance was higher in warm conditions.