How Does the Brain Make
Sense of An Object?
Imagine you’re in a gift shop on Black Friday.
Though it may be stressful, the average shopper’s brain is
computing the surrounding array of shapes, colors, motions, smells
and sounds with seeming ease. Princeton neuroscientist Anne Treisman
researches how the human brain manages complex visual information
in a process called “binding.” Her research suggests
that a central factor in solving or failing to solve these visual
riddles is a person’s spatial attention.
Studies suggest that our brains code one object
at a time. By momentarily focusing on one object, we can bind the
features of the object clearly. After the features have been bound
into correct groupings, we then give real-world interpretations
to the information collected. For example, our ability to visually
decipher a box of pens among boxes of cards is based on data concerning
pens, boxes, and cards we’ve collected over time.
However, when we are visually overloaded, the
binding of features can fail. For example, when research participants
are given less than a second to attend to an array of images that
include the letter "S" as well as straight lines nearby
it, they often report seeing dollar signs, where no dollar signs
To explain these observations, Treisman proposes
that sensory stimuli are initially registered both in separate feature
maps and in a location map. We recombine the features by focusing
on one object at a time and form a temporary representation, or
object token, of the features currently in the attended location.
We can then compare the object token to a store of knowledge built
up over time and identify the object as, for example, a cat, or
a pencil, or a telephone. The object token tells us what it looks
like at this moment of time and updates its position and appearance
if it moves and changes. It also allows us to represent novel objects
that we have never seen before and therefore cannot identify. We
seem to be limited to holding three or four object tokens at a time
in temporary memory, and we lose the bindings even for those if
attention is attracted elsewhere.
Treisman studied a patient with Balint’s
syndrome, a disease characterized by lesions to the parietal cortex,
which destroy the ability to localize objects in space. Treisman
and her collegues predicted that this would also lead to failures
of object binding and confirmed that the patient did indeed see
illusory combinations of features, even with presentations of just
two colored letters for up to ten seconds. (Treisman’s paper
on this subject was published by the Royal Society in 1998, Vol.