Face blindness during a pandemic

Recently while out walking my dog Jack, I encountered a blond woman pushing a toddler in a stroller while walking her dog.  I stopped to chat asking her how old her son was now and she responded amiably. About a year and a half ago three women on our block gave birth within a month of each other.  One woman has blond hair and two have dark hair.  As soon as we had ended our chat and I was walking on, I realized that she had the wrong dog.  The blond has a black lab and this dog was a curly terrier.  I then realized that the woman I had approached was a complete stranger, not one of my neighbors.

Face blindness, or prosopagnosia, is a neurological condition resulting in trouble identifying human faces.  It is usually caused by damage to the fusiform gyrus in the posterior temporal lobe and anterior portion of the occipital lobe.  Oliver Sacks famously introduced this condition to popular culture in his 1987 book The Man Who Mistook His Wife for a Hat.  Up to 2.5% of people are born with congenital face blindness, mostly inherited in an autosomal dominant pattern.  Acquired face blindness may be caused by head trauma, strokes or tumors affecting the fusiform gyrus.  A more insidious form of face blindness occurs in many people with Alzheimer’s disease, even in the early stages. The tau-containing neurofibrillary tangles of Alzheimer’s disease are first seen in the medial portion of the anterior temporal lobes.  With time, these neurofibrillary tangles can spread backwards into the fusiform gyrus. 

I have early-stage Alzheimer’s disease, and although I have only mild cognitive impairment, I have been having increasing trouble recognizing faces, even of people I know well.  Many of my neighbors are hard for me to recognize until I hear their voices or see the dog they are walking.  This has become all the more problematic now during the COVID pandemic because of the universal mask wearing when out and about.  On the other hand, I suspect that many normal people are having some trouble recognizing faces covered by masks. Before the pandemic, I would often be embarrassed by not recognizing or misidentifying an acquaintance while out walking my dog.  Now not so much.  It seems that most walkers like me are less inclined to greet passers-by, perhaps because we are unsure who they are. We are all now covering important facial features used for facial recognition. Perhaps everyone now is experiencing a degree of prosopagnosia.