The “uncanny phenomenon” describes the feeling of unease associated with seeing an image that appears human. While prosthetic hands are known to induce this effect, little is known about this phenomenon from the viewpoint of prosthesis users.
Researchers studied perceptions of eeriness and human-likeness for images of different types of mechanical, cosmetic, and anatomic hands among nine individuals with an upper-limb prosthesis, ten people with lower-limb amputations, 16 prosthetists, 20 participants with no prosthetic training, and 23 control participants who were trained to use a myoelectric prosthetic hand simulator. The researchers found that the upper- and lower-limb prosthesis user groups showed a reduced uncanny phenomenon (i.e., significantly lower levels of eeriness) for cosmetic prosthetic hand devices compared to the other groups, with no associated reduction in how these stimuli were rated in terms of human-likeness.
However, a similar effect was not found for prosthetists with prolonged visual experience of prosthetic hands or for the group with short-term training with the simulator. These findings, which were published in the June issue of Psychonomic Bulletin & Review, in the prosthesis users therefore seem likely to be related to limb absence or prolonged experience with prostheses.