Pixar’s WALL-E manages to kick you straight in the feels with its tale of a lonely robot, yet you don’t think twice about dumping an old microwave on the curb. Why the difference in emotion? Researchers have been trying to find that sweet spot and are now, after the release of a new study from Toyohashi University, one step closer. The team from Japan has found the first neurophysiological evidence of human’s ability to empathize with robots who are perceived to be in pain.

“I think a future society including humans and robots should be good if humans and robots are prosocial,” says study co-author Michiteru Kitazaki to Inverse. “Empathy with robots as well as other humans may facilitate prosocial behaviors. Robots that help us or interact with us should be empathized by humans.”

Pepper is the first humanoid robot designed to live with humans.

Until now we’ve only had a foggy idea of how the human brain responds to robots in moments that could provoke human empathy. Previous studies have demonstrated that people empathize more with human-looking robots (but not too human-looking) than mechanical robots, but one’s general ability to have empathy for our mechanical underlings has not been predictive if that empathy will actually be felt.

In this study, published in Scientific Reports, the researchers performed electroencephalography, a neurological test that involves attaching electrodes to someone’s head and measuring the electrical activity in the brain, on 15 healthy adults. They looked at pictures of either a robot hand or human hand in a not-painful or painful situation, like a finger being cut with a knife (like a less intense version of the knife game in Aliens).

Image from the study measuring empathy for robot and human hands.

The event-related brain potentials for empathy toward the humanoid robot were similar to the humans in perceived pain, causing the researchers to believe that we can empathize with robots in a similar fashion. It’s important to note, however, that the top-down process of empathy was weaker towards robots than humans.

“The ‘top-down process of empathy’ is the process that takes time for 350 milliseconds or more to recognize a situation and have it affect our cognition or consciousness,” says Kitazaki. “Thus it is not contagious or automatic empathy.”

Besides measuring brain activities using EEG (the brain electrical potentials) Kitazaki and his team also measured subjective ratings, asking questions like: How do you think the hand in the picture is feeling pain? How do you feel about the unpleasantness in the picture? While people rarely said that they thought the robot felt pain, their brain activity showed otherwise.

Paro the robot can help curb your loneliness for $5,000.

One goal of the study is that this work will contribute to the development of human-friendly robots who will get our sympathy. There’s been progress in this, the most famous robot likely being Paro, the adorable baby seal-bot that has been found to help older adults reduce stress and loneliness. Another emerging application for social robots is their role as a therapy tool for autistic children.

If we feel more empathy for robot companions our social interactions with them will be bettered and we’ll get more out of these likely beneficial relationships. You don’t feel empathy if you crack your iPhone, but you would feel sad if your robot-friend broke its arm.