This is a video of David, who had a brain hemorrhage resulting in a number of problems including acquired prosopagnosia (face-blindness) and a problem with "route finding" or navigating. In this video David tries and struggles to explain what it is that he sees when he views faces. He has lost the ability to remember faces as a result of his brain injury.
The thing that I find most interesting about this video is when David explains that his disability in perceiving faces and another problem with visual perception has resulted in an aversion to being among crowds, and also difficulty with dealing with visually crowded places such as a very full refrigerator or a shop full of displayed goods. He describes this as a "dyslexia of vision". Because David has acquired prosopagnosia he can tell that this problem with crowds is due to his brain injury. Before the hemorrhage he used to love crowded places. People who have been labelled as autistic and parents of kids diagnosed as autistic often describe being unable to cope with crowds and supermarkets as a behavioural characteristic of autism. David's experience appears to indicate that a difficulty with coping with visually crowded places could have prosopagnosia, possibly in combination with other visual processing issues, as a cause, and in light of the fact that prosopagnosia (acquired and developmental) is thought to be a fairly common and under-diagnosed disability, I've got to wonder how many of these supposedly autistic people who can't tolerate crowds and supermarkets have disabilities that are really sensory and social problems caused by unidentified prosopagnosia or caused by some kind of unidentified visual processing disorder.
Another aspect of prosopagnosia which could easily be mistaken for autism is a coping strategy that people without face memory typically use - memorizing many different details of a person's appearance for identification. For example, a person who cannot recognize faces might pay close attention to the design or colours on the shirt of a person who the prosopagnosic needs to remember, and also try to remember if that person wore glasses, or what their hair was like. An enhanced attention to details, including visual details, is a universally recognized feature of autism/Asperger syndrome, and it is easy to see how the detail-memorizing coping strategy of prosopagnosics could be misinterpreted as a special autistic gift for attending to details.
I think it's a very good thing that we can view David giving a first-hand explanation of his experiences and perceptions, rather than having to rely on an interpretation from a doctor or a researcher. Thank you David for sharing!