Researchers have found the first neurophysiological evidence of humans' ability to empathise with robots in perceived pain.

Researchers at the Department of Information Science and Engineering, Toyohashi University of Technology in collaboration with researchers at the Department of Psychology, Kyoto University, performed electroencephalography (EEG) in 15 healthy adults who were observing pictures of either a human or robotic hand in painful or non-painful situations, such as a finger being cut by a knife.

Event-related brain potentials for empathy toward humanoid robots in perceived pain were similar to those for empathy toward humans in pain.

The results suggest that we empathise with humanoid robots in a similar fashion as we do with other humans.

However, the beginning of the top-down process of empathy is weaker for empathy toward robots than toward humans.

In top-down processing of empathy, known as cognitive perspective-taking or theory of mind, the feelings of others are fully imagined and understood.

It may be caused by humans' inability in taking a robot's perspective, researchers said.

It is reasonable that we cannot take the perspective of robots because their body and mind (if it exists) are very different from ours, researchers said.

The study will contribute to the development of human-friendly robots whom we feel sympathy for and comfortable with.