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
[See New Scientist 26/6/99] 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."
| 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 |