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You too could have seemingly superhuman mental skills. All
you have to do is switch off part of your brain. Sounds bizarre?
Rita Carter
JAMES can tell you the precise time-to the
second-without looking at a clock. Jennifer can measure
any-thing to within a fraction of an inch just by glancing at
it. And Christopher can speak 24 languages including a couple of
his own devising. Amazing? Definitely. But unusual? Not
necessarily. According to a controversial new theory you too can
do these things. Or at least you could-if only you could just
stop being so clever for a moment.
Christopher, James and Jennifer are autistic savants-people
who score low on IQ tests and have severe
difficulties in communicating and interacting with others but
who nevertheless have seemingly superhuman competence in a
specific area like music, art or maths. About one in ten autistic
people have notable talents, but truly prodigious savants
like Stephen Wiltshire, who can draw spectacularly detailed and
accurate representations of buildings, or the lightning
card-counting calculator played by Dustin Hoffman in the film Rain
Man are very rare. There have probably only been about
100 people described as savants since the phenomenon was first
identified a century ago and only about 25 are alive at the
moment. Such is our fascination with these people that nearly
all of them are publicly known and celebrated, and many of their
skills have been studied exhaustively. Yet there is still no
generally accepted understanding of how savants do whatever it
is that they do. Theories range from enlargements of certain
specialised brain regions to the simple "practice makes
perfect"-but none of them alone satisfactorily explains all the
weird anomalies.
The latest contribution to the puzzle
is startling because it proposes that savant skills-far from
being unique,are possessed by everyone, and might even be
unleashed with quite simple, existing technology.
The idea comes from psychologists Allan Snyder and D. John
Mitchell from the Centre for the Mind at The Australian National
University in Canberra. Essentially they think that savant
skills are the manifestation of brain processes that happen
within us all, all the time, but are usually speedily swamped by
more sophisticated conceptual cognition. While this high-level
stuff fills our consciousness, the
savant-style information-crunching that the researchers suggest
precedes it is relegated to the unconscious back rooms of the
brain.
"It's not that savants are cleverer than the rest of us," says
Snyder, "it's just that most of us go one step further in our
brain processing-from detailed facts to meaningful concepts,and
once we've done that we can't go back."
Snyder and Mitchell formulated their theory from analysis of
many existing studies of savants-mainly mathematically
gifted ones . Among the findings they rely on are brain-imaging
experiments, which reveal the extent of unconscious
processing that goes on before we ever become aware of
perceptions, thoughts and feelings.
A visual image falling on the retina, for example,
takes about a quarter of a second to pop up in a person's
mind as a conscious perception. Before that moment, each element
of the image- including its colour, shape, movement and
location-is identified separately by various specialised regions
in the brain. These components are then assembled into a pattern
which is shunted onwards to regions that attach meaning to it.
Normally we have no idea that all this is happening-we only
become conscious of it after the detailed processing is complete
and we have a fully constructed perception.
"What matters for survival is that we have a concept we can work
on-it's a face and it's friendly, say-not a mass of detail about
how we arrived at that conclusion," says Snyder. "So in normal
people the brain takes in every tiny detail, processes it, then
edits out most of the information leaving a single useful idea
which becomes conscious." Taking these ideas a step further, he
asserts: "In savants the suppression doesn't happen so they see
the picture in fantastically detailed components, like
individual pixels in a photograph."
Using the same reasoning, Snyder believes that if, for example,
you were asked to calculate the day of the week on which any
particular date falls (an obsession peculiar to savants) or to
discern the precise pitch, length
and sequence of notes in a musical
score, you would do it, more or less instantly, in your
unconscious mind. But because knowing what day of the week 1
September 2056 would be is of no practical use, he thinks the
information would be edited out before it passed into
consciousness. Equally, because notes in isolation usually carry
little meaning you would tend to hear the music
as a melody rather than as separate sounds.
If Snyder and Mitchell are correct in supposing that savant
cognition is happening in us all, is it possible that we could
learn to shift our consciousness back a gear and become aware of
it? Niels Birbaumer of the Institute of Behavioural Neurobiology
at the University of Tilbingen, in Germany, an enthusiastic
supporter of Snyder and Mitchell's theory, believes we could.
Birbaumer recently led a team that fitted paralysed patients
with scalp electrodes that picked up signals from the brain and
translated them into movement of a computer cursor. The patients
first had to learn to control brain activity that was normally
unconscious (New Scientist, 16 January, p 4). Birbaumer
thinks it would be possible to access preconscious savant
cognitive processes in much the same way-and that some people
have already learnt to do so, without even realising what they
were doing.
'The most commonly
favoured explanation for savant talents is that they are
"islands" of highly developed ability, which are probably linked
to physically enlarged specialist brain regions'
Accessing the subconscious
He cites, for example, a non-autistic student whose calculating
skills rival those of the best mathematical savants. Electrical
monitoring of the student's brain waves while he was doing a
calculation showed that his brain was more active than usual at
the start but less active just before he answered
(Psychophysiology, vol 33, p 522). "Later cognition involves
more cortical activity and is associated with conceptual
thinking," says Birbaumer. "This student seems to be able to
prevent this activity from occurring when he is calculating-
leaving him free to access the earlier lowlevel processes."
Other researchers in the field-though expressing polite interest
in Snyder and Mitchell's theory-remain sceptical that we all
have latent savant skills. The most commonly favoured
explanation for savant talents is that they are "islands" of
highly developed ability, probably linked to physically enlarged
specialist brain regions. In most people the development of such
skills is held back because the brain's resources are focused
from an early age on conceptual thinking and what is known as
"global processing"-pulling together various thoughts and
perceptions and extracting meaning from the overall picture
rather than concentrating on the concrete details of each
perception.
Autistic people seem to be unable to process things in this way.
The result is a detailed but incoherent cognitive style
described by autism experts Uta Frith from the Institute of
Cognitive Neuroscience at University College London, and
Prancesca Happé, senior scientist at the Institute of
Psychiatry, also in London, as "weak central coherence". Their
idea is different from Snyder and Mitchell's because they assume
that savant processing never happens in non-autistic
people-consciously or unconsciously. They believe the drive
towards central coherence is so strong that it sweeps
perceptions and thoughts into meaningful concepts before every
tiny detail of them is registered, so we wouldn't be able to
access this information.
Happé' explains: "If you were able to look inside the brain of
an autistic savant I think you would find that their talent
arises from very specific and circumscribed brain areas which
are neurologically isolated from the areas which bind things
together to make concepts. This allows the areas dedicated to
savant abilities to develop without interference from parts of
the brain which deal with concepts. As a result they may turn
into large specialised brain areas like those that normal people
have for speech."
The idea that unusually enlarged brain regions may create
exceptional artistic, mathematical or musical skills in the
people who possess them took an interesting turn recently. An
anatomical study of Einstein's carefully
preserved brain showed the area associated with
maths was bigger than normal and not dissected by the usual
groove. Grooves often mark the boundaries of functional brain
areas, so it's fascinating to toy with the notion that the
mathematical "module" in his brain had annexed neurons from an
area next door that would normally do something else.
The trouble with the big brain hypothesis is that anyone's brain
will enlarge or get denser in an area that is constantly active,
so it is hard to know if an enlarged module is the cause or
result of a particular skill. Vilayanur
Ramachandran, Director of the Center for Brain and
Cognition at the University of California, San Diego, has
charted neuronal hijacking in cases of "phantom
limbs"-when amputees continue to feel their lost body
parts because the brain regions that once gathered sensory
signals from the limb are drawn into the regions monitoring
neighbouring body parts. He thinks something similar might
explain the astounding quality of savant cognition. "Maybe when
the brain, or a bit of it reaches a critical mass new and
unforseen properties emerge," he speculates. "So a
doubling of neurons wouldn't produce a doubling of talent but a
hundred-fold increase"
A simpler explanation comes from Michael Howe, a psychologist at
Exeter University who has studied both autistic and non-autistic
people with exceptional skills and believes that constant
practice is generally enough to account for both types of
talent. "Savants seem to just 'see' things effortlessly," he
says, "but I think if a non-autistic chess
player who has been immersed in the game for thirty or
forty years looks at a game in progress they just 'see' the
position and the best moves in a similar way." He adds: "The
main difference between experts and savants is that savants do
things which most of us couldn't be bothered to get good at."
'One celebrated
artistic savant, named Nadia, drew stunningly animated pictures
of prancing horses in perfect proportion and perspective, from
the moment she could grasp a pencil'
Not just practice
Howe admits, though, that mere practice cannot account for the
abilities shown by very young savants, simply because they have
not had time to hone their skills. One celebrated artistic
savant, named Nadia, drew stunningly animated pictures
of prancing horses in perfect proportion
and perspective from the age of three. She did not seem to learn
the skill. Unlike normal children, who go through very specific
stages as they develop drawing ability, such as putting huge
heads on people and showing limbs as sticks, Nadia was drawing
brilliantly from the moment she could grasp a pencil. And there
are children who can do the amazing day of the week
calculations, who have not yet learnt to divide and have
developed the skill without adult help.
It may be that all very young children perceive the world in a
savant-like way. One incredible skill shown by children is
language acquisition. Eight-month-old babies seem to carry out
fantastic calculations in order to work out where word
boundaries fall in a stream of speech (New Scientist, 21
August, p 36). They do not consciously work it out. They
simply learn to "know" when a word begins and ends, just as a
mathematical savant may say they just "know" the square
root of a six-figure number.
Adults, by contrast, have to labour over learning these patterns
in a new language; simply immersing themselves in it is usually
not enough. Similarly some researchers believe that perfect
pitch-a skill common in musical savants-is easily acquired by
children but rarely develops in adulthood. And eidetic
memory-the automatic perception, storage and retrieval of visual
images in photographic detail-is far more common in children
than in adults.
Savant-like skills may be lost-or hidden, according to Snyder
and Mitchell's theory-in non-autistic people as they grow up
because of a shift in the way we process information. Imaging
studies show that brain activity in newborn babies is limited to
regions we are unconscious of in adults but which
register incoming sensory information and respond to it by
generating urges, emotions and
automatic behaviour. The cerebral cortex-the area associated
with conscious thought and perception-becomes active within a
few months, however, and as the child grows up an increasing
proportion of information processing is done cortically. This
shift accelerates in non-autistic children around the age of
eighteen months, when they start to babble, and language
acquisition may help to "kick-start" activity in the
frontal cortex where conceptual processing is mainly carried
out.
In autistic children this shift appears to be slowed or
incomplete and so their savant-like processing style may be
preserved. Autistic savants who do seem to make the change,
albeit belatedly, may thus lose their abilities. Nadia, for
example, lost much of her prodigious talent when she finally
mastered language around the age of 12.
Language development also seems to bring about the dominance of
one hemisphere of the brain. In right-handers this is nearly
always the left hemisphere, where the main language regions
develop, but in left-handers language may occupy the right
brain. Many researchers argue that savant skills tend to be
those which are associated more with the right hemisphere:
music, identifying mathematical patterns
and art, for example, rather than
skills that are predominantly associated with the
left-hemisphere. Even the rare savants who have amazing word
power, like Christopher, tend to be less interested in reading
or the meaning of words, and more interested in skills like
translation. Because of this, many have suggested that savant
skills are produced by a dominant right hemisphere which has
flourished in the absence of effective communication with or
inhibition by the left.
'There are a number
of extraordinary cases in which people have suddenly developed
savant-like abilities. One 9-year-old boy was transformed from
an ordinary schoolkid to a genius mechanic affer part of his
brain was destroyed by a bullet'
Held back
"Autistic people often show both structural and functional
dysfunction in the left hemisphere," says Wisconsin psychiatrist
Darold Treffert, author of a book called Extraordinary
People: Understanding Savant Syndrome, back in 1989. "Most
cases are probably due to some prenatal interference with brain
development which prevents normal development of the cortex and
left hemisphere," he says. "Testosterone, for example, is
known to inhibit left-hemisphere development and in male fetuses
temporary slowing of the left hemisphere may be a normal
developmental stage. In autism that slowing may be protracted
beyond normal, resulting in an overdeveloped right hemisphere
and stunted growth on the left. This could explain why autism,
and savant skills, are about six times more common in males
that in females."
His theory seems to be supported by a number of extraordinary
cases in which normal people have suddenly developed savant-like
abilities after left-sided brain injuries. One 9-year-old boy,
for example, was transformed from an ordinary school-kid to a
genius mechanic as part of his left hemisphere was destroyed by
a bullet.
And Bruce Miller and co-workers at University of California Los
Angeles School of Medicine recently reported five patients who
developed amazing drawing skills after dementia destroyed part
of the left side of their brains (Neurology, 51, p 978). "One of
our patients had spent his life changing car stereos and had
never shown any interest at all in art," says Miller. "Then he
developed dementia which destroyed neurons in the left frontal
totemporal cortex-an area which gives meaning to things-and
suddenly started to produce sensational images recalled from
early childhood. It was though the destruction of those brain
cells took the brakes off some innate ability that had been
suppressed all his life, and opened access to an amazing
personal memory store he never knew he had."
As yet it isn't clear whose interpretation of these cases is
correct, if indeed anyone's is, but Snyder thinks there might be
a way to test it. He is planning an experiment which, he hopes,
the unconscious savante, will be unleashed at the flick of a
switch. Magnetic pulses can interfere with
normal brain activity. If you time and posit the surge
just right, it can temporarily ti off activity in a particular
region. Snyder's plan is to "switch off" the conceptualising
area. If his theory is correct, and if can find the area, this
should cause the normally pre-conscious savant skills burst into
consciousness. "I'm thinking of trying it on myself first," says
Snyder. "If I start to get crystal clear pictures of my
childhood or sudden knowledge of prime
numbers really know I'm onto something."
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Can studying dead brains
ever tell us anything about genius
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WHAT would Albert Einstein make of
all the recent fuss about the size and shape of his
brain?
Just after his death in 1955, his brain was weighed,
measured and photographed: its weight
proved to be only average. Now, however; the photographs
and measurements have been re-examined and his brain
declared "exceptional". According to The Lancet
(19 June) parts of his parietal lobe, an area of the
brain associated with visuospatial abilities and
mathematical ideas, are larger than normal and not
divided by a fold in the usual way. The suggestion is
that perhaps this allowed areas of his brain to develop
more cross connections than usual.
Of course, we can't actually ask Einstein if he thinks
that his theory of relativity was the product of his
parietal lobe. But his own writings may shed some light
on the roots of his genius.
Curiously, one of his explanations relies not so much on
any special ability but on a reaction to a disability.
Einstein claimed that he was very late learning to speak
and even after he did, he found whole sentences tricky,
rehearsing them in an undertone before speaking them out
loud. That delayed development, Einstein said, meant
that he went on asking childlike questions about the the
nature of space, time and light long after others had
simply accepted the adult version of the world.
It is true that many of the questions Einstein asked
himself were simple. But to think through the answers
and see that they struck at the heart of physics surely
required something very much more. A second and more
conventional explanation might be found in the
intellectual company he kept.
There was one book of philosophy which Einstein said he
"studied with fervour and admiration shortly before the
discovery of the theory of relativity" and without
which, "it is very well possible that ... I would not
have arrived at the solution". The book was David Hume's
A Treatise of Human Nature, in which the
18th-century philosopher argued that there is nothing we
can rely on totally from our experiences of the world
around us.
Einstein described how the theory of special relativity
came to him "suddenly with the thought that our concepts
and laws of space and time can only claim validity
insofar as they stand in a clear relation to our
experiences; and that experience could very well lead to
alteration of these concepts and laws."
A childlike delight in the questions adults forget and a
reading list that was unusual for a physicist might
explain part of his genius. But Einstein also had
another more modest view-that he was no genius at all
but the press had made him into a new kind of hero.
Certainly, since the first headlines of 1919 when The
Times announced "Revolution in Science-Newtonian Ideas
Overthrown", Einstein never left the public eye. "The
mystery of non-understanding" of his ideas simply
boosted his appeal, he believed.
After just two years of fame he complained: "It strikes
me as unfair... to select a few individuals for
boundless admiration, attributing superhuman powers of
mind and character to them. This has been my fate, and
the contrast between the popular estimate of my powers
and achievements and the reality is grotesque."
Such modesty is endearing-but he can't be modest about
his greatest year. In 1905, at the age of 26, he sent
for publication papers on a new way to determine the
size of molecules, an explanation of Brownian
movement, the particle-like behaviour of light
(which won him the 1922 Nobel prize), and the theory of
special relativity (which should have won him another).
Nothing in scientific history stands comparison.
Perhaps we need enlarged parietal lobes after all. But
we need to exercise a little caution. At the time of
Einstein's death, any suggestion of reading character
from bumps on the brain would have been repugnant given
the fate of millions in the Second World War. We now
know a lot more about cognitive modules within the
brain.
But still not nearly enough to even begin guessing
whether Einstein owed his genius to his childhood
experiences, his reading, his friends, his incredible
motivation or any of a thousand other factors. But let's
be thankful for that-it would be a dull world if our
great talents-and weaknesses-could be measured by a
brain scan.
[New Scientist 26/6/99]
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Rita Carter is author of Mapping
the Mind, published in paperback by Seven Dials,
price £14.99
Further reading: Extraordinary Minds by
Howard Gardner, (Phoenix, 1998) "Is integer arithmetic
fundamental to mental processing? The mind's secret
arithmetic" by Allan W. Snyder & D. John Mitchell,
Proceedings ot the Royal Society B, vol 268, p587 (1999)
James and Jennifer are not the real names of the
people described
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