Prosopagnosia

1867

Antonio Quaglino (1817–1894), Giambattista Borelli (1813–1891)

The French neurologist Jean-Martin Charcot once had a patient who tried to shake hands with a man who had bumped into him; the other man was himself, reflected in a mirror. This inability to recognize faces, or prosopagnosia, is a relatively rare disorder. It is one of several kinds of visual agnosias, or inability to recognize familiar objects, that is not associated with general intellectual impairment. Nor is it a problem of vision; people suffering from prosopagnosia typically have perfectly good vision. It is a disorder resulting from damage to the brain, usually in both the temporal and parietal lobes. Recently, however, individuals with developmental prosopagnosia, which is present from birth, have been found, indicating a possible genetic basis for face recognition.

Historically the condition was first described, though not named, in the medical literature in 1847. The first full account of a patient, however, came from two Italian ophthalmologists, Antonio Quaglino and Giambattista Borelli, in 1867. They offered a detailed case study of a man who had lost the ability to recognize faces and the exteriors of houses after having a stroke in the right hemisphere of his brain. The term prosopagnosia (“face not knowing”) was given to the disorder in 1947. More recently, neurologist and author Oliver Sacks gives a fascinating account of prosopagnosia in his book The Man Who Mistook His Wife for a Hat (1985).

Curiously, it is not only human faces that are affected by the disorder. There are accounts of farmers who fail to recognize their cows or sheep and bird-watchers who lose the ability to distinguish between species of birds.

Contemporary research using brain imaging techniques such as functional magnetic resonance imaging (fMRI) suggest that face recognition is a special function. Research with primates, including humans, indicates that there are specialized neurons (or brain cells) dedicated to recognizing faces. Apparently, damage to these cells leads to the inability to recognize faces, even our own.

SEE ALSO Brain Imaging (1924), Mirror Neurons (1992)

Nude Before the Mirror by German artist Karl Piepho (1869–1920), oil on canvas.