A Podcast with Oliver Sacks. This week in the magazine, Dr. Oliver Sacks explores prosopagnosia, or face blindness—a neurological condition that he himself has. Here Sacks talks with Blake Eskin about the comic and painful situations that arise when one is unable to recognize faces, how he compensates for face blindness, and what public awareness of the condition could do for those who suffer from it. Oliver Sack's latest book, "The Mind's Eye," will be published this fall. Listen to the mp3 on the player above, or right-click here to download. Subscribe to The New Yorker Out Loud for a weekly conversation with contributors to The New Yorker. The strange-face-in-the-mirror illusion.
An intriguing article has just been published in the journal Perception about a never-before-described visual illusion where your own reflection in the mirror seems to become distorted and shifts identity. To trigger the illusion you need to stare at your own reflection in a dimly lit room. The author, Italian psychologist Giovanni Caputo, describes his set up which seems to reliably trigger the illusion: you need a room lit only by a dim lamp (he suggests a 25W bulb) that is placed behind the sitter, while the participant stares into a large mirror placed about 40 cm in front. The participant just has to gaze at his or her reflected face within the mirror and usually “after less than a minute, the observer began to perceive the strange-face illusion”. The set-up was tried out on 50 people, and the effects they describe are quite striking: At the end of a 10 min session of mirror gazing, the participant was asked to write what he or she saw in the mirror.
Quot;Can our brains see the fourth dimension?" The Visual Nerd In You Understands Curved Space. You’ve heard that space is curved – that’s gravity. You’ve also been told that you cannot really understand curved space. Sure, you can come to know curvy mathematics by studying general relativity or differential geometry, but you cannot grasp curved space in your bones…for the obvious reason that, in our everyday human-level world, space is flat, and so we have a brain for thinking flat. Or, at least, that’s what they say. But there is at least one variety of curvy mathematics that your brain comprehends so completely that you don’t even know you know it.
It concerns your visual field, and your innate understanding of the directions from you to all the objects in your environment. In thinking about your visual field, it is best to imagine a sphere around your head, recording the directions to all objects in one’s environment. Consider now the way these poles project…First, notice that each pole appears straight in your visual field. Moving dots optical illusion reveals the power of silencing. Neural basis of congenital face blindness : Neurophilosophy.
Prosopagnosia is a neurological condition characterised by an inability to recognize faces. In the most extreme cases, the prosopagnosic patient cannot even recognize their own face in the mirror or a photograph, and in his 1985 book The Man Who Mistook His Wife For A Hat , the neurologist Oliver Sacks describes the extraordinary case of a farmer who lost the ability to recognize the faces of his cows! Also known as face blindness, prosopagnosia is associated with damage to specific parts of the temporal lobes. But there are also documented cases of patients who have the condition in the absence of brain damage.
The form of face blindness is congenital: those who inherit a genetic mutation are born with an impaired ability to recognize faces. A new study, published online in the journal Nature Neuroscience, now provides the first evidence of a neurobiological substrate for congenital prosopagnosia. (From Thomas et al 2008) Related: Thomas, C. et al (2008).