RESEARCH scientists believe that they have located the area in
the brain which is responsible for the way in which people see
faces in inanimate objects. The work was carried out at Stanford
University, California, and the results were published in
The Journal of Neuroscience (24 October
2012).
The face of Mother Teresa in a bun or Jesus on a piece of toast
regularly crops up in news stories. Now, work with brain scanners
and electrodes has located two small areas of the brain which seem
to be the place where faces, in particular, are recognised.
The researchers worked with a 45-year-old man who suffered from
drug-resistant epilepsy, who had had electrodes implanted into his
brain to try to overcome this. This enabled them to stimulate very
small areas in an area low down towards the back of the brain,
which has long been implicated in face recognition - the fusiform
gyrus.
Earlier studies, using techniques that measured blood-flow in
different parts of the brain, had shown that the fusiform gyrus is
active when we see and identify faces. But this kind of brain
scanning has been criticised because it is relatively
coarse-grained in the detail that it shows, and also it cannot tell
us what the active portions of the brains are doing.
Stimulation with electrodes is much more precise, and can be
used to disrupt areas of interest to discover exactly what
cognitive functions depend on them.
In this case, the researchers were able to disrupt the
recognition of real faces. When the current was applied to the
correct spot in the brain of the fully conscious patient, he
immediately reported that the face of the scientist talking to him
had become strangely distorted.
The effect was instantaneous, and is unnerving to watch. It can
be seen in a film on the internet (http://bit. ly/W2uWjU). The
patient says: "You just turned into somebody else. Your face
metamorphosed. . . You almost look like somebody I've seen before,
but somebody different. That was a trip. . . It's almost like the
shape of your face, your features drooped."
The disruption of one small area did not stop the patient from
seeing a human face, but it caused him to see a different one. This
is further evidence that the process of face recognition is
complex, and proceeds in stages.
The work also confirms the innate, subconscious nature of face
recognition, and the way in which we cannot help seeing faces even
when we know that they are not there. This has given rise to a
number of Christian "sightings" of holy faces, with the subsequent
veneration of foodstuffs. Muslims, however, tend to see words in
Arabic script rather than faces.