快猫短视频

JAMES can tell you the precise time鈥攖o the second鈥攚ithout looking
at a clock. Jennifer can measure anything to within a fraction of an inch just
by glancing at it. And Christopher can speak 24 languages鈥攊ncluding 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鈥攊f only you could just stop being so clever for a moment.

Christopher, James and Jennifer are autistic savants鈥攑eople 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 鈥減ractice makes
perfect鈥濃�攂ut none of them alone satisfactorily explains all the weird
anomalies.

The latest contribution to the puzzle is startling because it proposes that
savant skills鈥攆ar from being unique鈥攁re 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.

鈥淚t鈥檚 not that savants are cleverer than the rest of us,鈥� says Snyder, 鈥渋t鈥檚
just that most of us go one step further in our brain processing鈥攆rom
detailed facts to meaningful concepts鈥攁nd once we鈥檝e done that we can鈥檛 go
产补肠办.鈥�

Snyder and Mitchell formulated their theory from analysis of many existing
studies of savants鈥攎ainly 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鈥檚 mind as a conscious perception. Before that
moment, each element of the image鈥攊ncluding its colour, shape, movement
and location鈥攊s 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鈥攚e only become conscious of it after the detailed
processing is complete and we have a fully constructed perception.

鈥淲hat matters for survival is that we have a concept we can work
on鈥攊t鈥檚 a face and it鈥檚 friendly, say鈥攏ot a mass of detail about how
we arrived at that conclusion,鈥� says Snyder. 鈥淪o 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.鈥� Taking these ideas a step
further, he asserts: 鈥淚n savants the suppression doesn鈥檛 happen so they see the
picture in fantastically detailed components, like individual pixels in a
辫丑辞迟辞驳谤补辫丑.鈥�

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 T眉bingen, in
Germany, an enthusiastic supporter of Snyder and Mitchell鈥檚 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 (快猫短视频, 16 January, p
4). Birbaumer thinks it would be possible to access pre-conscious savant
cognitive processes in much the same way鈥攁nd that some people have already
learnt to do so, without even realising what they were doing.

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鈥檚
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). 鈥淟ater cognition involves more cortical
activity and is associated with conceptual thinking,鈥� says Birbaumer. 鈥淭his
student seems to be able to prevent this activity from occurring when he is
calculating鈥攍eaving him free to access the earlier low-level
辫谤辞肠别蝉蝉别蝉.鈥�

Other researchers in the field鈥攖hough expressing polite interest in
Snyder and Mitchell鈥檚 theory鈥攔emain sceptical that we all have latent
savant skills. The most commonly favoured explanation for savant talents is that
they are 鈥渋slands鈥� 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鈥檚 resources are focused from an early age on
conceptual thinking and what is known as 鈥済lobal processing鈥濃�攑ulling
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 Francesca Happ茅, senior scientist at the Institute of Psychiatry,
also in London, as 鈥渨eak central coherence鈥�. Their idea is different from Snyder
and Mitchell鈥檚 because they assume that savant processing never happens in
non-autistic people鈥攃onsciously 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鈥檛 be able to access this information.

Happ茅 explains: 鈥淚f 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.鈥�

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鈥檚 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鈥檚 fascinating to toy with the notion that the mathematical
鈥渕odule鈥� 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鈥檚 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 鈥減hantom
limbs鈥濃�攚hen 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. 鈥淢aybe when the brain,
or a bit of it, reaches a critical mass new and unforeseen properties emerge,鈥�
he speculates. 鈥淪o a doubling of neurons wouldn鈥檛 produce a doubling of talent
but a hundred-fold increase.鈥�

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. 鈥淪avants seem to just `see鈥� things
effortlessly,鈥� he says, 鈥渂ut 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鈥� the position and the best moves in a similar way.鈥� He adds: 鈥淭he main
difference between experts and savants is that savants do things which most of
us couldn鈥檛 be bothered to get good at.鈥�

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 (快猫短视频, 21
August, p 36). They do not consciously work it out. They simply learn to 鈥渒now鈥�
when a word begins and ends, just as a mathematical savant may say they just
鈥渒now鈥� 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鈥攁 skill common in
musical savants鈥攊s easily acquired by children but rarely develops in
adulthood. And eidetic memory鈥攖he automatic perception, storage and
retrieval of visual images in photographic detail鈥攊s far more common in
children than in adults.

Savant-like skills may be lost鈥攐r hidden, according to Snyder and
Mitchell鈥檚 theory鈥攊n 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鈥攖he area
associated with conscious thought and perception鈥攂ecomes 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 鈥渒ick-start鈥� 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.

Held back

鈥淎utistic people often show both structural and functional dysfunction in the
left hemisphere,鈥� says Wisconsin psychiatrist Darold Treffert, author of a book
called Extraordinary People: Understanding Savant Syndrome, back in
1989. 鈥淢ost cases are probably due to some prenatal interference with brain
development which prevents normal development of the cortex and left
hemisphere,鈥� he says. 鈥淭estosterone, 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.鈥�

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 after part of his left hemisphere was
destroyed by a bullet.

And Bruce Miller and co-workers at the 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,vol 51, p 978). 鈥淥ne of our patients had spent his life changing
car stereos and had never shown any interest at all in art,鈥� says Miller. 鈥淭hen
he developed dementia which destroyed neurons in the left frontotemporal
cortex鈥攁n area which gives meaning to things鈥攁nd suddenly he started
to produce sensational images recalled from early childhood. It was as 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.鈥�

As yet it isn鈥檛 clear whose interpretation of these cases is correct, if
indeed anyone鈥檚 is, but Snyder thinks there might be a way to test it. He is
planning an experiment in which, he hopes, the unconscious savant will be
unleashed at the flick of a switch. Magnetic pulses can interfere with normal
brain activity. If you time and position the surge just right, it can
temporarily turn off activity in a particular region. Snyder鈥檚 plan is to
鈥渟witch off鈥� the conceptualising area. If his theory is correct, and if he can
find the area, this should cause the normally pre-conscious savant skills to
burst into consciousness.

鈥淚鈥檓 thinking of trying it on myself first,鈥� says Snyder. 鈥淚f I start to get
crystal clear pictures of my childhood or a sudden knowledge of prime numbers
I鈥檒l really know I鈥檓 onto something.鈥�

James and Jennifer are not the real names of the people described