Editor’s pick: Excluded from the uncanny valley
From Bob Cockshott
New Scientist. Issue 3100. November 19th 2016. p.60.
The experience described in the letter seems to suggest that there is more to face recognition than simple memory or faces, or could it be that there are aspects of the perception of faces in particular that make them especially memorable? Faces are easy to personify because they are usually found on people. Perhaps it is the ability to detect the person behind the face that has become amiss in the letter’s author following his stroke, and maybe this ability feeds into face memory? Such a relationship would explain the author’s inability to notice the uncanny valley, and it would also explain why a personifying synaesthete like myself is also a super-recognizer.
I’ve had a read of the interesting article by Laura Spinney that this letter was a comment about, and I think the Perceptual Mismatch Theory of the Uncanny Valley Effect probably offers a more plausible explanation of my a prosopagnosic might be unable to detect the uncanny valley than the competing Category Uncertainty Theory. The article explained the two theories and evidence supporting them. To summarise, the CUT explains the UVE as the result of confusion about what type of thing one is looking at (for example robot or human?), while the PMT explains the UVE as resulting from unease or perceptual confusion when different features or parts of the thing or being viewed have dissimilar levels of human-like appearance (for example the face and skin look realistic but the eyes do not move like human eyes). I think the case of a prosopagnosic not detecting the UVE when people with normal face perception do is support for the PMT theory rather than the other because as far as I know, prosopagnosia does not involve inability to classify faces or bodies as human or non-human, while I believe there is evidence supporting the idea that prosopagnosia can be the result of not being able to perceptually integrate the features of the face as a whole that is recognizable as a unique or distinctive mix of many attributes and features. A non-prosopagnosic person should be able to perceive a face or body as a whole made up of parts, and notice if one or more elements has a level of humanity that does not match other parts, as in the PMT, while a prosopagnosic might not. Of course, research is needed to investigate my armchair speculations.