Head Movements Can Express Emotions – Perhaps for Robots Too

People often nod, tilt, or bow their heads as they sing or talk. The body language is often used to reinforce verbal messages and improve communication. 

A new study by researchers from McGill University reviewed if the head movements themselves, can actually convey emotions.

Psychology investigators Drs. Steven R. Livingstone and Caroline Palmer discovered resounding evidence that head movements are very effective in communicating emotions. In fact, the researchers found that people were highly accurate at judging emotions based on head movements alone, even in the absence of sound or facial expressions.

This finding suggests that visual information about emotional states available in head movements could aid in the development of automated emotion recognition systems or human-interaction robots, said Livingston and Palmer.

And, human-interaction robots could be effective in a variety of settings. For example, expressive robots could potentially serve a range of functions, particularly where face-to-face communication is important, such as at hotel reception desks and as interactive care robots for the elderly.

Using motion-capture equipment to track people’s head movements in three dimensions, Livingstone and Palmer recorded vocalists while they spoke or sang with a variety of emotions.

The researchers then presented these video clips to viewers without any sound, with the facial expressions of vocalists hidden so that only their head movements were visible. Viewers were then asked to identify the emotions that the vocalists intended to convey.

“We found that when people talk, the ways in which they move their head reveal the emotions that they’re expressing. We also found that people are remarkably accurate at identifying a speaker’s emotion, just by seeing their head movements,” says Palmer.

“While the head movements for happy and sad emotions differed, they were highly similar across speech and song, despite differences in vocal acoustics,” Livingstone said.

“Although the research was based on North American English speakers, the focus on head movements creates the possibility for studying emotional communication in contexts where different languages are spoken.”

Surprisingly, the idea for the study emerged from a noisy pub.

“One night in Montreal I was in a bar with my lab mates,” Livingstone said. “It was a lively evening, with lots of people, dim lights, and some very loud music.

“At one point my friend started to talk me; I knew he was excited though I couldn’t make out what he was saying or see his face clearly. Suddenly I realized it was the animated way that he was bobbing his head that told me what he was trying to say.”

Said Palmer, “Our discovery may lead to new applications in situations where sound is not available, such as automated recognition of emotional states in crowd behavior or in hearing impairments, by making use of head movements when watching someone talk.

“It also has applications in computing and robotics, where the addition of expressive head movements may help make humanoid robots more lifelike and approachable.”

Source: McGill University/EurekAlert