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10/04/2006
Messing with the Brain
Two weeks ago, in a discussion of refrigerants and the ozone
layer, I may have left an overly optimistic impression of the state
of progress in restoring the ozone layer. When I said that we had
turned the corner, I didn’t mean to imply that everything was
back to normal, especially in view of a Reuters news item dated
October 2 posted on AOL News. The article says that the
European Space Agency has found that the hole in the ozone
layer over Antarctica hit a record size this year. At some 11
million square miles, the Antarctic ozone hole is expected to
recur for decades at about the same size before finally returning
to normal by about 2065. However, according to the World
Meteorological Organization, the ozone layer over us in North
America will be back at pre-1980 levels by about 2049. There is
light at the end of the tunnel.
Now let’s revisit another topic in an earlier column (10/10/2002).
The topic was the brain and the amazing performance of savants
in such varied fields as mathematics, music, memorization and
painting. A savant may, for example, memorize a whole book
word for word after a single reading but not comprehend the
meaning. It’s as though the savant copies each word in the brain
but makes no attempt to put the words in context. In some cases,
there has been damage to a specific region of the brain known to
be involved in analysis and putting information into proper
context.
Some researchers, notably Allan Snyder and colleagues at the
Australian National University and other Australian universities,
concluded that such brain-damaged savants are unencumbered by
the need to expend energy sorting out the meaning of the letters,
numbers, words or musical notes they take into their brains. The
Australians wondered whether normal individuals couldn’t
duplicate some of the prowess of the savant if the same part of
the brain was temporarily deactivated or disabled. The part of
the brain the researchers targeted is called the left anterior
temporal lobe.
As I mentioned back in 2002, the Australian researchers decided
to deliberately interfere with the functioning of that part of the
brain through the use of magnetic pulses, a procedure termed
transcranial magnetic stimulation (TMS). Sure enough, the
researchers found that when they turned on the TMS machine,
certain subjects performed better in certain artistic endeavors or
in calendar calculations, an area where some savants shine.
In researching material for the present column, I came across an
article by Lawrence Osborne in the July 22, 2003 New York
Times headlined “Savant for a Day”. Osborne described his
experience during an interview with the aforementioned Allan
Snyder in a lab at the University of Sydney in Australia.
Osborne agreed to submit himself to TMS. He described the
TMS machine as the Medtronic Mag Pro, a machine designed to
stimulate or slow down regions of the brain during surgery.
Osborne had a series of electrodes placed on his head and
attached to something that reminded him of a hair dryer.
Osborne admitted to being rather apprehensive after signing the
release form prior to being attached to the Mag Pro. (I can relate
to his apprehension, having had an MRI of my own brain some
years ago.) When the experiment began, Osborne was asked to
draw a cat. He described his first cat as looking more like a stick
figure of an insect than a cat. As his brain was subjected to the
magnetic pulses, he drew more cats. At the end of the session,
even though he had drawn all four cats, he hardly recognized the
later ones as his own work. After 10 minutes of TMS, the last
cats had tails that were “more vibrant” and “their faces were
personable and convincing”. In his words, he had gone from “an
incompetent draftsman to a very impressive artist of the feline
form”.
In addition to drawing the cats, Snyder asked Osborne to read the
following lines:
A bird in the hand
is worth two in the
the bush
Osborne said, “A bird in the hand is worth two in the bush.”
Snyder smilingly asked Osborne to repeat this a few times, then
turned on the Mag Pro for about five minutes and asked Osborne
to read the lines again. With the part of the brain that puts things
in context subverted, Osborne for the first time saw the extra
“the”.
Such experiments support Snyder’s belief that disabling this
particular region of the brain frees one to see just the words
themselves without relating them to any particular saying or
context. Without the hindrance of trying to make sense of the
input to the brain, it seems that normal people can at least show a
semblance of savant-like capability.
Not everyone has embraced Snyder’s views. Skeptics say that
his experiments on improved artistic abilities after TMS, much
like Osborne’s cat drawings, were too subjective to judge.
Perhaps to counter such arguments, Snyder and his colleagues
are continuing their work, trying to put it on a more quantitative
basis. In the September 2006 issue of Discover, there’s a very
brief item by J.R. Minkel describing some of this work, a kind of
“jelly-bean counting” akin to guessing the number of jelly-beans
in a glass jar. I found more details on this recent work on a
British Psychological Society (BPS) Research Digest site.
In this work, Snyder and colleagues flashed a varying number of
“blobs” (the “jelly-beans”) on a computer screen, the number
ranging from 50 to 150. Twelve volunteers were the subjects
and they were only given 1.5 seconds looking at the screen to
guess the number of blobs. They guessed the number of blobs
before and after 15 minutes of TMS. Ten of the 12 volunteers
showed significant improvement in estimating the number of
blobs after TMS. The BPS site cites two examples. One subject,
out of 20 tries before TMS, got none of her guesses within 5 of
the correct number. After TMS she got 6 out of 20 within 5.
Another volunteer got 3 out 20 within 5 of the correct number
before TMS, 10 out of 20 after TMS.
The subjects lost their improved counting ability an hour after
the TMS and also showed no improvement when they underwent
a sham TMS accompanied by the same noises that went with the
real thing but without the magnetic pulses. I’m guessing that the
volunteers were happy that their savant-like counting expertise
went away. I certainly wouldn’t want to think that the magnetic
pulses had disrupted my brain permanently! Hey, I like to think
that at least a few of my columns have some degree of context in
them. Oh, and if you think some of the stuff I write is a bit
weird, I assure you that the MRI of my brain showed it to be
perfectly normal. At least that’s what they told me.
Allen F. Bortrum
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