Imagine a chair. It has physical attributes: four legs, a seat, some sort of a back. Now imagine a human face. It also has physical attributes: eyes, a nose, a mouth. But, remarkably, the ways we process these features in our brains—and more crucially how we remember them—are significantly different, relying on wholly distinct neural pathways. Social memory it turns out is a completely different cognitive task than, say, remembering everyday inanimate objects, numbers and dates, or events. Nowhere is this phenomenon more apparent than with the neurological condition known as prosopagnosia, or “face blindness.” Sufferers of which lack almost all ability to recognize faces, despite other recall faculties being unaffected.
Once thought exceptionally rare and predominantly the result of head trauma, mounting evidence over the last few years suggests that hereditary face blindness (or developmental prosopagnosia) is much more common than previously thought. One explanation for the under-reporting might be that many people with the condition, remarkably, don't even know they have it. The Prosopagnosia Research Centers—a collaboration between Harvard University and the University College London—notes that "developmental prosopagnosics often do not realize that they are unable to recognize faces as well as others. Of course, they have never recognized faces normally so their impairment is not apparent to them."
The introduction of prosopagnosia to much of the broader public came in the form of the curious case of "Dr P" in The Man Who Mistook His Wife for a Hat by acclaimed neurologist and best-selling author Oliver Sacks. Dr P, as the title of this classic book suggests, famously couldn't even recognize his own wife (though he knew her voice). But the strange tale of "Dr P" isn't where the story ends. A lesser-known and recently revealed fact adds a meta-twist to the plot: Oliver Sacks, himself, suffers from prosopagnosia. In his forthcoming book, The Mind's Eye, Sacks writes about his own experience with face blindness. More than once, he writes, he has apologized for "almost bumping into a large bearded man, only to realize that the large bearded man was myself in a mirror."
Another notable prosopagnosic is the renowned artist Chuck Close, known for his large, hyper-realistic portraits. Close attributes his inability to remember faces as a major influence on his work and process. In an interview with The Wall Street Journal, Close remarks: "I don’t know who anyone is and have essentially no memory at all for people in real space, but when I flatten them out in a photograph, I can commit that image to memory in a way; I have almost a kind of photographic memory for flat stuff."
The World Science Festival 2010 brings together these two prolific geniuses from opposite ends of the creative spectrum to discuss their experiences of facing a faceless world in Strangers in the Mirror.
Just how common is prosopagnosia? What are the developmental implications for a child who lacks social memory, as she looks for emotional validation in the faces that surround her? What does it mean to be a “super-recognizer” (the newly discovered neurological antithesis of a prosopagnosic)? And are the biological underpinnings the same? What does all of this say about the ways we interact with—and come to “know”—each other? Award-winning NPR journalist Robert Krulwich will help unravel these questions with Sacks and Close.