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Spotlight on Science: Rutsuko “Ruth” S. Nagayama

Spotlight on Science: Rutsuko “Ruth” S. Nagayama

We spoke with Rutsuko “Ruth” S. Nagayama, Professor of Psychology at Shizuoka Eiwa Gakuin University, for the latest Spotlight on Science Q&A. Here, she reflects on an article she co-authored in 2007 for PRESENCE: Teleoperators and Virtual Environments. “The Uncanny Valley: Effect of Realism on the Impression of Artificial Human Faces” has been one of the journal’s Top 5 Most Downloaded Articles in the past year. Read the article for free on our SOS page.

 Can you talk a little bit about “the uncanny valley?”

The uncanny valley is a hypothesis about the psychological reaction when we see a robot, and was proposed by a roboticist Masahiro Mori in 1970. Mori argued that  although it would be a good thing to make a robot's appearance more humanlike, people could feel uncomfortable with robots that were almost (but not perfectly)  humanlike.

A graph used by Mori to explain his hypothesis is well known. In his graph, the horizontal axis represents how much artificial objects (robots, dolls, prosthetics, etc.)  resemble real human beings. The vertical axis represents a kind of impression score of artificial objects as rated by human observers.

Mori predicted that the more closely artificial objects resembled real humans, the more comfortable our impression of them would be. But when their resemblance reached very close to real humans, we would have negative impressions of them. Mori depicted the occurrence of the negative impressions as a valley in the graph. This portion of the graph is called the uncanny valley. Mori warned that obviously robotic appearance is okay, but making them highly humanlike runs a risk of falling into the valley.