Scientists from the RIKEN Guardian Robot Project have recently built an android child named Nikola that can successfully convey six basic emotions – happiness, sadness, fear, anger, surprise, and disgust – by changes in facial expression. In a new study published in the journal Frontiers in Psychology, the researchers tested how well people could identify the six facial expressions and found that the recognition accuracy was quite impressive.
Nikola’s face is animated by 29 pneumatic actuators which control the movements of artificial muscles, and other six actuators in charge of head and eyeball movements. To find the proper location for the actuators in the android’s face, the scientists followed the Facial Action Coding System (FACS), a comprehensive, anatomically-based system which has been used extensively to study and describe all visually discernible facial movements. Since the actuators are controlled by air pressure, the movements are silent and smooth.
In order to test whether Nikola’s facial expressions were understandable, the researchers first enrolled a person certified in FACS scoring. This person was able to identify each facial action unit, indicating that Nikola’s facial movements accurately mimicked those of a real human.
In a second step, the scientists enrolled a group of non-specialist, “naïve” participants, who were asked to identify the emotions expressed by the android’s face. While the recognition accuracy of all emotions was significantly higher than chance level, participants had trouble identifying emotions like disgust, since Nikola’s silicone skin was less elastic than real human skin and could not properly form wrinkles, such as the nose wrinkles characteristic for the facial expression of disgust.
“In the short term, androids like Nikola can be important research tools for social psychology or even social neuroscience,” said study lead author Wataru Sato, a neuroscientist at RIKEN. “Compared with human confederates, androids are good at controlling behaviors and can facilitate rigorous empirical investigation of human social interactions.”
Although Nikola still lacks a body, the ultimate goal of the Guardian Robot Project is to build androids that could help people, particularly those who live alone and are in need of physical assistance. “Androids that can emotionally communicate with us will be useful in a wide range of real-life situations, such as caring for older people, and can promote human wellbeing,” Dr. Sato concluded.