Friday, 8 March 2013

The Uncanny Valley

As some of you may know, I am fond of cybernetics and spend a considerable amount of time reading about the last technological achievements. A few days ago, I came across an article talking about the problem faced by designers when trying to make robots appear more familiar and more particularly, about a problem known as the uncanny valley. The uncanny valley, first described by Masahiro Mori, a Japanese roboticist, is a phenomenon which points out the fact that robots and prosthetic limbs can become more humanlike and equally familiar to humans, until a certain point where they will start appearing strange.

In an empirical study conducted by F. MacDorman , it has been concluded that, when confronted to the uncanny face of a humanlike robot, it often reminded subjects of a dead or unconscious person. Thus, this would mean that people are not comfortable around androids because they look like zombies. MacDorman suggested that robot designers should not be too ambitious and should try to build elaborated humanoid robots which look artificial rather than humanlike robots.

Then, I was reminded of a photo of a person wearing a very fancy prosthetic leg. Thinking it would be a great picture to illustrate this article, I went through a bit of research and finally found it on a blog post which talked about ways of solving the problem of the uncanny valley for prosthetic legs, using 3D printings. The result is quite impressive and it would almost make you want to have a prosthetic leg as those are some beautiful pieces of art. This is proof that the best way to jump over the uncanny valley is not to aim for the human likeness but to make something obviously artificial but with a touch of art.

In my opinion, I think that robots and prosthetic limbs remind people of death because of the way they move, but we might also consider the fact that human beings may not be able to predict if robots are going to act like normal robots or like humans. On the other hand, prosthetic limbs make humans not comfortable as they inspire pain and pity because of the mobility issue they engendered. The latter might show a difference in the effect of the uncanny valley on robots and prosthetic limbs, while robots might look more familiar by staying artificial, prosthetic limbs might be more acceptable just by making them more fashionable or by actually showing off their technological capacities, to prove they are not a disadvantage.


  1. Fascinating stuff. I've always had a strong experience of the uncanny valley when watching CG animated films that aspire to realism in the portrayal of human characters. The CG Arnold Schwarzennegeger in Terminator 4 in partiular makes me feel queasy. There's just something wrong, but it's hard to say what. I think that's why they burn his skin off so quickly:

  2. Recently there was the world premiere of a muscle and nerve-controlled arm prosthesis. The surgical team led by Professor Rickard Branemark of Sahlgrenska University Hospital carried out the first operation of its kind to connect one arm prosthesis to the nerves and muscles of a patient who is amputated. Here is a video conveying the process of a muscle and nerve-controlled arm prosthesis:

    I was just wondering does the 'uncanny valley' also affect the amputee themselves when wearing a human like prosthetic limb? Or does the advantages of just having one and the advantages it brings (especially one controlled by you) for the amputee outweigh this phenomenon? There are a number of theories that have been proposed to explain the cognitive mechanism underlying the uncanny valley phenomenon which I enjoyed reading. These theories can be found on the uncanny valley wikipedia page. Nice post François, interesting stuff!