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Face memory
deficit holds
object lesson
By Bruce Bower
A brain-damaged man who can’t remember faces has nosed into a scientific debate
about how people learn to recognize
other complex objects. Deaf users of sign
language also have a hand in this dispute.
The man’s facial failures are one symptom of a general inability to perceive configurations of object parts, suggests a new
investigation led by psychologist Cindy
Bukach of the University of Richmond
in Virginia. The man stumbles at identifying not only people’s faces but also
computer-generated, three-part objects
called Greebles, even after extensive
training, Bukach’s team reports online
December 8 in Neuropsychologia.
Bukach and her colleagues studied LR,
a man who fails to recognize his daughter when shown a picture of her but
remembers distinctive facial features,
such as Elvis’ sideburns. Damage in a
car accident to a brain area just under
the right temple caused this condition,
called prosopagnosia.
“There are many ways in which face
recognition can be disrupted, but our
evidence shows that LR’s type of prosop-
agnosia impairs recognition of objects
with multiple parts, with faces as the
most obvious example,” Bukach says.
Relative positions of the eyes, nose and
If face recognition depends on a general
capacity for learning to recognize multi-
part objects, Duchaine holds, healthy
volunteers should recognize novel Gree-
bles as poorly as prosopagnosia patients
do at first but perform better than patients
after seeing lots of Greebles. LR’s Gree-
ble difficulties exceeded those of healthy
volunteers from the start, a sign of fun-
damental object-recognition problems
that make the results hard to interpret,
Duchaine contends. “These new results
don’t help us understand mechanisms
used for face processing,” he says.
A brain-damaged man who can’t recognize faces also fared poorly at learning
to distinguish computer-generated “Greebles” (such as these) from one another.
Each Greeble displays a distinctive configuration of three appendage types.
