PERSONAL RELATIONSHIPSeffect on our ability to
identify them, whereas
upending, say, an aero-
plane or a house seems
to have little effect on
whether we can recognize
them. The face-inversion
effect is thought to occur
because we process faces
in an unusually holistic
fashion, paying careful
attention to the distances
between the different
features – a proce-
dure that’s particularly
hampered by inversion
(as in the photograph on
the right).
Psychologists who
think face-recognition is
a learned skill, on the
other hand cite research
by Isabel Gauthier from
the 1990s. After training
participants to distin-
guish between a set of weird putty-like figures called “greebles”,
Gauthier found that as they developed this skill, merely looking at gree-
bles triggered activity in the fusiform-face area just as looking at faces
did. Similarly, in the 1980s the MIT psychologists Rhea Diamond and
Susan Carey claimed to have found a face-inversion effect among dog
experts. This supported the idea that face processing represents a form
of acquired visual expertise, distinguished from other examples simply
because nearly all of us have developed it.
Those people who lack the ability to recognize faces are called
prosopagnosic by psychologists, from the Greek prosopo meaning “face”
and agnosia meaning “without knowledge”. The condition was first
described by the German neurologist Joachim Bodamer in the 1940s
after he observed the defects exhibited by two patients who’d been brain
damaged in World War II. For decades, the condition was thought to
be extremely rare and nearly always a result of brain damage. However,
The Margaret Thatcher illusion. Apart from it
being upside down, there doesn’t seem much
wrong with this picture of a smiling Margaret
Thatcher. But turn the picture the right way
up and it becomes freakishly apparent that the
picture has been doctored in a way that makes
her look extremely sinister. This illusion was first
documented by Peter Thompson at the University
of York, and it works in part because when the
face is inverted we process the eyes and mouth
separately from the rest of the face, whereas when
the face is upright, we process the face and its
distorted features simultaneously.