Biological substrates of savantism are unclear, but some correlates have included a larger amygdala (in children) and hippocampus (J. Neurosci. 2004;24:6392-401). Perseverative fixation on a single activity that is their sole avenue of socialization and reward, coinciding with their area of savant-level talent, suggests that savantism may derive from the extreme focus of reward on a single activity and structurally altered paralimbic reward substrates, but this is currently speculative.
Another group of patients whose disease can sometimes enhance creativity are patients with frontotemporal dementia possibly reflecting the reduced behavioral inhibition that characterizes FTD (Arch. Neurol. 2004;61:842-4). Some FTD patients have developed newly expressed artistic skills reflected in greater volumes of less constrained art. But contrary to popular belief, psychiatric disease is not a pathway to enhanced creativity. A large study of eminent men concluded that depression and personality disorders were common, especially among writers, and that their prevalence among the gifted exceeded that in the general population. But those disorders were generally a hindrance to creative ability, and psychosis was a frank handicap (Br. J. Psychiatry 1994;165:22-34).
Some individuals have increased dexterity to carry out creative plans for reasons that range from environmental influences on normally structured nervous systems to altered "wiring diagrams." But regardless of how we have acquired our talents, the ways we choose to use them depend in part on our personality and temperament, which will be our focus in the next issue.
Dr. Caselli is a professor of neurology at the Mayo Clinic, Scottsdale, Ariz.