Empathy toward virtual humans depicting a known or unknown person expressing pain.

This study is about pain expressed by virtual humans and empathy in users immersed in virtual reality. It focuses on whether people feel more empathy toward the pain of a virtual human when the virtual human is a realistic representation of a known individual, as opposed to an unknown person, and if social presence is related to users' empathy toward a virtual human's pain. The 42 participants were immersed in virtual reality using a large immersive cube with images retro projected on all six faces (CAVE-Like system) where they can interact in real time with virtual characters. The first immersion (baseline/control) was with a virtual animal, followed by immersions involving discussions with a known virtual human (i.e., the avatar of a person they were familiar with) or an unknown virtual human. During the verbal exchanges in virtual reality, the virtual humans expressed acute and very strong pain. The pain reactions were identical in terms of facial expressions, and verbal and nonverbal behaviors. The Conditions by Time interactions in the repeated measures analyses of variance revealed that participants were empathic toward both virtual humans, yet more empathic toward the known virtual human. Multivariate regression analyses revealed that participants' feeling of social presence--impression that the known virtual character is really there, with them--was a significant predictor of empathy.