Acquired Savant Syndrome

Probably some 25 years ago I was able to participate in a NIH study where we recruited a group of autistic individuals that had calendar calculating abilities.  The idea was to compare their brains to those of neurotypicals using neuroimaging. Since fMRI had not been invented (or conceived) we had to rely on computerized tomography and PET for comparisons.  The study was meant to disclose between-group differences in neural networks used for the aforementioned mathematical calculations.  All individuals were given calendar calculating tasks which for neurotypicals involved learning a series of rules that had to be memorized and practiced on a daily basis. Probably the most striking aspect of the study, was the fluidity of the calculations by autistic savants. While neurotypicals had to rely on a set or rules for calculations, no such obstacles were consciously perceived by autistics who quite spontaneously came up with correct answers.

Although I was good at math during my school years I will never be a good calendar calculator, my heart and interests are not there.  In my case I would not be able to learn the rules for calendar calculating, less apply the same. Neither will I  be able to recite over 22,000 numbers for pi like Daniel Tammet. I think the only way that anything like that could happen for me would be in terms of an acquired savant syndrome.

The capacity to perform certain mathematical feats can materialize after head injury, a phenomenon called acquired savant syndrome.  More commonly, gains in artistic creativity (rather than math prowess) have been  observed following brain injuries like stroke, aneurysms and even neurosurgical interventions requiring removal of certain parts of the brain. This is the brain’s great balancing act, wherein you lose some functions while gaining others.

I am not sure we have gained a great deal of knowledge from acquired savant syndromes, however, a few tidbits do seem to stand out. There does not appear to be a pattern as to what injuries provide for acquired savant abilities and multiple areas appear to be involved in varying degrees of severity. Case reports appear to be few, but for creativity, it is my impression that the cerebellum has been mentioned somewhat frequently.

It may be of importance that for acquired savant abilities, skills do not become noticeable immediately after injury.  Special skills require time to evolve and become manifest. It is not that injured individuals acquire the skills by practice but rather there seems to be a time lag requirement for new brain connections to develop.  In effect the brain is a plastic structure capable of changing itself, a phenomenon called neuroplasticity. Linking different parts of the brain in new ways, or using areas of the cortex to process information for a new sensory modality appear to be a common motif in the emergence of novel properties or skills.  In effect, a blind person may not use his occipital cortex for seeing, but the same may receive connections related to touch (e.g., reading Braille).

Novel cross links of connectivity have been involved in the phenomenon of synesthesia where stimulation of one sensory pathway leads automatically to experiences in a second sensory pathway. A common form of synesthesia is that letters or numbers may be perceived as having intrinsic colors.  I have to wonder how many synesthetics were judged insane, before we acquired our modern understanding of the phenomenon.

synesthesia-1

Another lesson to be gained from acquired creativity after brain damage is that the same often exhibits an obsessive compulsive quality. The severity of this trait is such that affected individuals may develop features consistent with a mental disorder.  For some individuals obsessive compulsiveness may suffuse with traits characteristic of bipolar disorder. This comorbidity in acquired savant syndromes is not unexpected as  15 to 20% of bipolar disorders individuals also meet diagnostic criteria for obsessive compulsive disorders.

Nancy Andreasen is the Chair of Psychiatry at the University of Iowa Carver College of Medicine. Her major in college was English before turning to Medicine. She has conducted and published many studies on creativity emphasizing the fuzzy land in between creativity and some mental disorders, especially those of a bipolar nature (see the Creative Brain: The Science of Genius by Nancy Andreasen).

Creativity and savant abilities have also been seen in persons with serious mental disorders, including mental retardation and autism. Blind Tom Wiggins born autistic and enslaved in Georgia.  During his life he toured the nation and amazed crowds for some 40 years.  A person with an all consuming passion for music, he had an incredible repertoire of thousands of songs and an incredible ability to imitate sounds and reproduce music after hearing the same played once.

Patients with fronto temporal dementia may also exhibit increased artistic creativity that has been related to the amount of damage in the left temporal lobe. It is believed that such damage disconnects the temporal lobe from the frontal lobe, causing the latter to become disinhibited. A similar state may be seen in alcohol intake, and after taking certain drugs such as LSD. Not coincidentally, in one of our recent studies on cortical complexity (not published) we found major topographical changes in the frontal and temporal lobes of patients at risk for developing autism.

frontal temporal

Acquired savant abilities is an uncommon but fascinating subject. Many people believe that creativity is directly related to genes and the environment.  Johann Sebastian Bach was highly creative, but there were 20 other prominent musicians in his family.  Another side of the coin, or in this case argument, is that dedication and practice (with a dab of enthusiasm) are also necessary for success.  Ericsson’s 10-year rule is the notion that it takes at least 10 years (or 10,000 hours) of dedicated practice for people to master most complex endeavors (read more: http://www.time.com/time/health/article/0,8599,1879593,00.html#ixzz2Xok6rYzg ).  So in the polemic of creativity where do we accommodate acquired savant syndromes? There does not seem to be a simple explanation regarding genes, environment or practice for the same. In effect, brain lesions throw a small wrench into ongoing debates on creativity. It may be that genes, environment and brain lesions are all funneled by the same mechanism: corticocortical connectivity.

5 responses to “Acquired Savant Syndrome

  1. I wonder if that throws a wrench into the theories of Laurent Mottron and perhaps other scietnists who claim that autistics have inherently superior abilities and that is not a result of a brain dysfunction and these abilities can be tapped to leverage in occupational success and getting along with their parents. As far as the blind people and the occipital cortex, I think it may be possible that they can see using the occipital cortex. You’re probably familiar with the research of Paul Bach-Y-Rita and Yuri Danilov
    where they could stimulate certain nerves in the tongue that connected to the brain stem and allow blind people to see through the occipital cortex and sort of passing the need for intact eyes. Of course I may be getting some facts wrong.

  2. P.S. And one more thing you forgot to discuss is that these acquired savant skills can apparently come to the fore through transcranial magnetic stimulation and perhaps other neuromodulation techniques.

  3. My daughter was diagnosed with PDD/NOS in 1988. She eventuallly lost her diagnosis and has had a nornal outcome. When she was about 3 years old she became obsessed with the Disney film Sleeping Beauty and began drawing the three fairies Flora, Fauna and Meriwether. The drawings were amazing although I don’t consider her to be a savant in those early years at all. Here’s is a recent story about another three year old girl with autism who has a remarkable ability in painting:

    http://www.nydailynews.com/news/world/british-autistic-toddler-paintings-thrill-art-world-sell-crazy-article-1.1389426

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