States that scientists studying the links between the brain and
behavior find that attention is a general activity of the brain, but it
does not entail a general improvement in all brain systems involved in
stimulus processing. Study conducted by Michael Posner; Positron emission
tomography (PET); The two main centers of attention functions;
Details.
By
PT Staff, published on July 01, 1992
Brain/behavior Links
If attention is something you pay, then the cash register is in the
cortex, the topmost layer of tissue that forms the thinking part of the
brain. And the currency is nore-pinephrine, a neurotransmitter that turns
the register on and keeps it humming.
Scientists studying the links between the brain and behavior find
that attention is a general activity of the brain, but it does not entail
a general improvement in all brain systems involved in stimulus
processing. Rather, observes Michael Posner, Ph.D., it is conducted by a
designated network of neurons performing specific tasks in specific
locations. His studies suggest that nore-pinephrine is so central to the
operation of this network that a blockage somewhere along the way may
lead to attention deficit disorder, marked by inability to maintain
attention.
Head of the Center for the Cognitive Neuroscience of Attention,
based at the University of Oregon, Posner has conducted positron emission
tomography (PET) studies of normal persons responding to various stimuli.
Reported in Current-Directions (Vol. 1, No. 1), the studies show there
are two main centers of attention functions:
Posterior parietal lobe of the cortex. First in play, it is crucial
to orienting visual attention and shifting it from one location to
another. It improves the efficiency of information gathering at any
location by enhancing the function of individual brain cells, seen in
increased blood flow during PET scans. This area recognizes patterns,
visual word forms.
Right frontal cortex. This area is crucial to maintaining
alertness, as shown by activation on PET scans during tests of sustained
vigilance. The area also detects meaning in language, other modalities.
An alerting network, made up of fibers that respond to nore-pinephrine,
links the two areas from back to front. The neurotransmitter provokes the
system to pick up sensory signals and detect new targets. Posner believes
that attention deficit disorder may result from damage to this alerting
network.
PHOTO (COLOR): PET scan of a resting brain.
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