I was always uncomfortable with our model of brain activity as it
was obviously tentative. This is a way
more compelling model and far more useful.
We now have a research mission. Just
what does change as the waves pass through the brain itself? How does it compare between individuals?
In the meantime, put aside all you thought you knew and read this
item.
Just as clearly, polishing this model opens the door for better
diagnosis of brain disease protocols. We
will be able to isolate and describe flaws and develop work around therapies
which is already happening but without a precise working model.
'Brain waves' challenge
area-specific view of brain activity
by Staff Writers
Leuven, Belgium (SPX) Mar 22, 2013
Our understanding of brain
activity has traditionally been linked to brain areas - when we speak, the
speech area of the brain is active. New research by an international team of
psychologists led by David Alexander and Cees van Leeuwen (Laboratory for
Perceptual Dynamics) shows that this view may be overly rigid.
The entire cortex, not just
the area responsible for a certain function, is activated when a given task is
initiated. Furthermore, activity occurs in a pattern: waves of activity roll from one side of the brain to the other. [ This suggests a timing function is at work
and that this movement can be measured.
It is very suggestive and this speed may well be directly related to
mental potential - arclein ]
The brain can be studied on
various scales, researcher David Alexander explains: "You have the
neurons, the circuits between the neurons, the Brodmann areas - brain areas
that correspond to a certain function - and the entire cortex.
Traditionally, scientists
looked at local activity when studying brain activity, for example, activity in
the Brodmann areas. To do this, you take EEG's (electroencephalograms) to
measure the brain's electrical activity while a subject performs a task and
then you try to trace that activity back to one or more brain areas."
Activity waves
In this study, the psychologists explore uncharted territory: "We are examining the activity in the cerebral cortex as a whole. The brain is a non-stop, always-active system. When we perceive something, the information does not end up in a specific part of our brain. Rather, it is added to the brain's existing activity.
"If we measure the
electrochemical activity of the whole cortex, we find wave-like patterns. This
shows that brain activity is not local but rather that activity constantly
moves from one part of the brain to another. The local activity in the Brodmann
areas only appears when you average over many such waves."
Each activity wave in the
cerebral cortex is unique. "When someone repeats the same action, such as
drumming their fingers, the motor centre in the brain is stimulated. But with
each individual action, you still get a different wave across the cortex as a
whole. Perhaps the person was more engaged in the action the first time than he
was the second time, or perhaps he had something else on his mind or had a
different intention for the action.
"The direction of the waves
is also meaningful. It is already clear, for example, that activity waves
related to orienting move differently in children - more prominently from back
to front - than in adults. With further research, we hope to unravel what these
different wave trajectories mean."
The full text of the
study "Traveling waves and trial averaging: the nature
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