Re: EEG
Folks,
That "mirror system" of the brain was the main
point of the the BBC article cited by Randall:
http://news.bbc.co.uk/1/hi/health/4113891.stm
Talent 'changes way brain works'
This is related to a point that has been known for
decades: mental imagery activates relevant parts
of the sensory cortex that are is used to perceive
such images and of the motor cortex that are used
to control corresponding actions. The BBC article
cites fhurter evidence.
But I'd like to mention some qualifications:
1. It is certainly valuable evidence about how
the brain works, but it can only be interpreted
in conjunction with much, much more knowledge
about all the interacting mechanisms of the
brain, most of which are still poorly understood.
2. The word word "talent" in the headline of the
BBC article is inappropriate. A better term is
"motor experience" or "physical experience".
3. From my own personal experience in skiing (for
which I do not claim much, if any talent) I know
that watching a ski video (especially one made
for training skiers) can reactivate a "feel"
for the kinds of motions used in skiing. This
"feeling" is well known to sports instructors,
and studies show that such mental imagery
supported by videos can be very useful in
training.
4. Although those "mirror systems" can be dectected
in brain waves, it's not clear how reliable they
would be in detecting prior experience in criminal
investigations. Someone who wanted to disguise any
prior experience in dancing or skiing could probably
meditate on some totally different subject matter
while pretending to be attentive to the video.
On a related point, the excerpt below is from Chapter 2
of my _Conceptual Structures_ book, which was published
in 1984. Note the dates on the three studies reported:
1910, 1964, and 1972. Psychologists were doing a lot
of research on such issues over a century ago, but it
was killed by the behaviorists, who made it impossible
to publish any research on imagery or related phenomena.
Those studies weren't taken up again until the 1960s.
That's just one more bit of evidence about the disaster
that the behaviorists inflicted on psychology.
John Sowa
___________________________________________________________
Excerpt from Chapter 2 of _Conceptual Structures_ by John F. Sowa.
[Mental] images are so similar to sensory icons that people are
sometimes unaware of what is external and what is internal. Perky (1910)
told her subjects to "imagine a banana." While they were describing the
images, a faint, vertical yellow form was projected before their eyes.
Although most subjects originally imagined a banana lying horizontal,
they lined up their internal images with the external form without being
aware of it. Segal (1972) told subjects to "imagine a glass of iced tea"
and then projected a barely perceptible image in front of them. When the
external image was iced tea, the subjects reported ordinary mental
images of iced tea. But when the external image was an elephant, the
subjects reported unusual distortions and combinations such as a
caterpillar drinking iced tea. In general, the subjects assimilated the
external stimulus to the internal image without being aware of the stimulus.
Internal images can produce the same patterns of brain waves as the
sensory stimuli they are mimicking. Since brain waves are hard to
decipher, John (1964) chose a flickering light as the stimulus because
its rhythmic pattern could easily be detected. He conditioned cats to
obtain milk by pressing a lever in response to the light. When the
stimulus was first presented, its rhythmic pattern was found in the
visual projection area of the cat's cortex. As the conditioned reflex
became established, more widely scattered parts of the brain began to
show the rhythm. Not only did the pattern appear when the stimulus was
present, it occasionally appeared in the brain when the external
stimulus was absent. The spontaneously generated pattern did not cause
the cat to turn towards the lever, but the more often it appeared, the
more quickly the reflex was established. When the reflex became
completely automatic, the spontaneous pattern tended to disappear and
only reappeared when the animal made a mistake.
In terms that would give a behaviorist apoplexy, one could say that the
cat was "thinking" about the light. The more it pondered the situation,
the sooner it noticed the connection between the flickering light and
milk, and the more quickly the reflex was established. The pattern
disappeared when the reflex was fully established because, as the
introspectionists said, behavior becomes less conscious as it becomes
more automatic. One should not hazard too many guesses about a cat's
mental imagery on the basis of this experiment, but the least it shows
is that processes in the brain can regenerate patterns that resemble
sensory input. It also shows that learning involves more than
strengthening stimulus-response chains.
References:
John, E. Roy (1964) "Electrophysiological studies of memory mechanisms,"
in D. P. Kimble, ed., _The Organization of Recall_, New York Academy of
Sciences, New York, 294-321.
Perky, Cheves West (1910) "An experimental study of imagination,"
_American J. of Psychology_, Vol. 2.21, 422-452.
Segal, Sydney Joelson (1972) "Assimilation of a stimulus in the
construction of an image: the Perky effect revisited," in P. W. Sheehan,
ed., _The Function and Nature of Imagery_, Academic Press, New York,
203-230.