Uncanny Valley is a term explaining the goosebump feeling when we see robots, as well as realistic computer graphics, that are too close to human-like. This effect causes human brain to feel unsettling, which first discovered from robotics professor in 1978

According to this article, the researchers investigate the cause of uncanny with fMRI (functional magnetic resonance imaging) that measures blood flow in the brain. The result shows the brain’s conflict from one part recognising these realistic robot as ‘this is human… i think?’ Then, pass the signal to another brain part that distrust the signal. So, this conflict triggers emotional alarm (Amygdala) to conclude that these robots are ‘creepy’

“This means there is no one robot design that fits—or scares—all users. In my view, smart robot behaviour is of great importance, because users will abandon robots that do not prove to be smart and useful.”

-Professor Rosenthal-von der Pütten

reference – https://www.cam.ac.uk/research/news/scientists-identify-possible-source-of-the-uncanny-valley-in-the-brain