Thursday, December 9, 2010

Prosopagnosia: A Podcast with Oliver Sacks

A NEUROLOGIST’S NOTEBOOK is about prosopagnosia, or the inability to recognise faces and places. The writer describes his own difficulties recognising and remembering faces. He also has the same difficulty with places and often becomes lost when he strays from familiar routes.

At the age of seventy-seven, despite a lifetime of trying to compensate, he has no less trouble with faces and places than when he was younger. He is particularly thrown when seeing a person out of context, even if he was with that person five minutes before.

The writer gives several examples of his inability to recognize familiar people out of context, including his therapist and his assistant. After learning that his brother suffered from the same problem, the writer came to believe that they both had a specific trait, a so-called prosopagnosia, probably with a distinctive genetic basis.

He mentions several other people who have the same trait, including Jane Goodall and the artist Chuck Close. Face recognition is crucially important for humans, and the vast majority of us are able to identify thousands of faces individually, or to easily pick out familiar faces in a crowd.

People with prosopagnosia need to be resourceful and /or inventive in finding strategies for circumventing their deficits: recognising people by an unusual nose or beard, or by their spectacles, or a certain type of clothing.

The Notebook describes research done on the way the brain recognises facesand tells about the work of Christopher Pallis, Charles Gross, Olivier Pascalis, Isabel Gauthier, and other scientists. Above all, the recognition of faces depends not only on the ability to parse the visual aspects of the face—its particular features and their over-all configuration—and compare them with others, but also on the ability to summon the memories, experiences, and feelings associated with that face.

The recognition of specific places or faces goes with a particular feeling, a sense of association and meaning. He also briefly discusses déjà vu and Capgras syndrome and considers the difference between acquired prosopagnosia—through trauma, stroke or Alzheimer’s —and congenital prosopagnosia.

The writer discusses the work of Ken Nakayama and Brad Duchaine, who have explored the neural basis of face and place recognition. They have also studied the psychological effects and social consequences of developmental prosopagnosia. Severe congenital prosopagnosia is estimated to affect two to two and a half per cent of the population—six to eight million people in the United States alone.

A Podcast with Oliver Sacks : The New Yorker


  1. you see faces in fragments which brings to mind dyslexia/dysgraphia where letters in words and words in sentences also are perceived in fragments, moving around on a page for meaning to be misperceived. Any connection?

  2. Hi Rachel, thanks for your question. Oliver Sacks is an excellent writer and researcher who examines the experiences of people with complex neurological conditions. In particular he reveals how some people can interpret and perceive the world differently from the 'standard model.' In most cases these people have been diagnosed as having a neurological difficulty or have experienced trauma to specific regions of the brain.

    From these cases, we can more closely examine the area that lies between the nature and the complexity of our 'standard model' and the apparent 'mis-perception.'

    Unfortunately, we can draw few conclusions about neurological conditions and processes from the apparent similarity of 'symptoms' experienced, except that different conditions may overlap in a particular area of the brain or may affect or interfere with a particular neurological process.

    We are conditioned to find patterns and similarities in all things and feel accomplished when we detect one. Oliver Sacks has drawn our attention to this similarity or pattern and would have us take a note of it for future reference.

    We should certainly keep it in mind as we continue to seek out new and revealing insights into the brain's complexity.