 By
Darold A. Treffert, M.D.
Savant Syndrome is a rare, but spectacular, condition
in which persons with various developmental disabilities,
including Autistic Disorder, have astonishing islands
of ability or brilliance that stand in stark, markedly
incongruous contrast to the over-all handicap. In
some, savant skills are remarkable simply in contrast
to the handicap (talented savants). In others, with
a much rarer form of the condition, the ability
or brilliance is not only spectacular in contrast
to the handicap, but would be spectacular even if
viewed in a normal person (prodigious savant). There
are fewer than 100 reported cases of prodigious
savants in the world literature. The condition was
first named Idiot Savant in 1887 by Dr. J. Langdon
Down (better known for having named Down's Syndrome).
He chose that term because the word "idiot"
at that time was an accepted classification level
of mental retardation (IQ below 25) and the word
"savant" meant knowledgeable person derived
from the french word savoir, meaning "to know".
The term idiot savant has been largely discarded
now, appropriately, because of its colloquial, pejorative
connotation and has been replaced by Savant Syndrome.
Actually Idiot Savant was a misnomer since almost
all of the reported cases have occurred in persons
with IQs of 40 or above. The condition can be congenital
or acquired in an otherwise normal individual following
CNS injury or disease. It occurs in males more frequently
than in females in an approximate 6:1 ratio.
Savant skills occur within a narrow but constant
range of human mental functions, generally in six
areas: calendar calculating; lightening calculating
& mathematical ability; art (drawing or sculpting);
music (usually piano with perfect pitch); mechanical
abilities; and spatial skills. In some instances
unusual language abilities have been reported but
those are rare. Other skills much less frequently
reported include map memorizing, visual measurement,
extrasensory perception, unusual sensory discrimination
such as enhanced sense of touch & smell, and
perfect appreciation passing time without knowledge
of a clock face. The most common savant skill is
musical ability. A regularly re-occurring triad
of musical genius, blindness and autism is particularly
striking in the world literature on this topic.
Premature birth history is commonly reported in
persons with Savant Syndrome.
In some cases of Savant Syndrome a single special
skill exists; in others there are several skills
co-existing simultaneously. The skills tend to be
right hemisphere in type--nonsymbolic, artistic,
concrete, directly perceived--in contrast to left
hemisphere type that tend to be more sequential,
logical, and symbolic including language specialization.
Whatever the special skills, they are always linked
with phenomenal memory. That memory, however, is
a special type--very narrow but exceedingly deep--within
its narrow confines. Such memory is a type of "unconscious
reckoning"--habit or procedural memory--which
relies on more primitive circuitry (cortico-striatal)
than higher level (cortico-limbic) cognitive or
associative memory used more commonly and regularly
in normal persons.
Approximately 10% of persons with Autistic Disorder
have some savant abilities; that percentage is much
greater than in other developmental disabilities
where in an institutionalized population that figure
may be as low as 1:2000. Since other developmental
disabilities are much more common than autism, however,
the actual percent of persons with Savant Syndrome
turns out to be approximately half Autistic Disorder
and half other Developmental Disabilities.
Theories to explain Savant Syndrome include eidetic
imagery, inherited skills, concrete thinking and
inability to think abstractly, compensation &
reinforcement, and left brain injury with right
brain compensation. Newer findings on cerebral lateralization,
and some imaging and other studies that do show
left hemisphere damage in savants, suggest that
the most plausible explanation for Savant Syndrome
to be left brain damage from pre-natal, peri-natal
or post-natal CNS damage with migratory, right brain
compensation, coupled with corresponding damage
to higher level, cognitive (cortico-limbic) memory
circuitry with compensatory take over of lower level,
habit (cortical-striatal) memory. This accounts
for the linking of predominately right brain skills
with habit memory so characteristic of Savant Syndrome
(Treffert, 1989). In talented savants, concreteness
and impaired ability to think abstractly are locked
in a very narrow band but, nevertheless, with constant
practice and repetition can produce sufficient coding
so that access to some non-cognitive structure or
unconscious algorithms can be automatically attained.
In prodigious savants, some genetic factors any
be operative as well, since practice alone cannot
account for the access to vast rules of music, art
or mathematics that seems innate in these persons.
Once established, intense concentration, practice,
compensatory drives and reinforcement by family,
teachers and others play a major role in developing
and polishing the savant skills and memory linked
so characteristically and dramatically by this unique
brain dysfunction.
One of the pre-natal CNS injury mechanisms, which
has implications not only for Savant Syndrome but
other disorders as well in which male sex in over-represented,
is the neurotoxic effect of circulating testosterone
on the left hemisphere in the male fetus based on
observations and reported by Geschwind and Galaburda.
Since the left brain completes its development later
than the right brain, it is at risk for CNS damage
for a longer period of time to circulating-testosterone
(which can be neurotoxic) in male fetuses and that
left CNS damage, with right brain compensation,
may account for the high male:female ratio not only
in Savant Syndrome, but in autism, stuttering, hyperactivity
and learning disabilities as well.
The movie Rain Man depicted an autistic savant and
that term became almost a household word. It is
important to remember, however, that not all autistic
persons are savants, and not all savants are autistic.
What one sees in Rain Man are savant skills (lightening
calculating, memorization etc.) grafted on to autism
(narrowed affect, obsessive sameness, rituals etc).
It is also important to point out that the savant
in the movie is a high functioning person with autistic
disorder, but the disorder consists of an entire
spectrum of disabilities ranging from profoundly
disturbed to high functioning; not all autistic
savants function at such a high level.
For many years it was feared that helping the savant
achieve a higher level of functioning with treatment--"eliminating
the defect"--would result in a loss of special
skills, i.e. there would be a trade-off of right
brain special skills for left brain language acquisition,
for example. That has not turned out to be the case.
Quite to the contrary, "training the talent"
is a valuable approach toward increasing socialization,
language and independence. Thus the special skills
of the savant, rather than being seen a odd, frivolous,
trivial or distracting, become a useful treatment
tool as a conduit toward normalization in these
special persons. Some schools have begun to include
persons with Savant Syndrome into classes for the
gifted and talented as a method of enhancing further
this conduit toward normalization.
There are probably fewer than 25 prodigious savants
living at the present time. Some of those include
Leslie Lemke (music), Alonzo Clemens (sculpting),
Richard Wawro (painting), Stephen Wiltshire (drawing),
Tony DeBlois (music) to name some. Other prodigious
savants more recently described are in England,
Austrailia and Japan. A 1983 60 minutes program
on Savant Syndrome was particularly useful in bringing
this remarkable condition to more general attention
and of course the move Rain Man catapulted the condition
to national prominence. There have been a number
of other television specials and several movies
about Savant Syndrome over the past 10 years. My
book Extraordinary People: Understanding Savant
Syndrome reviews the condition in depth.
Information on the above can be obtained by request
from:
Darold A. Treffert, M.D.
W4065 Maplewood Lane
Fond du Lac, Wi 54935
920-921-9381 home/office
920-926-8933 fax
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