In some people, neurological conditions can set loose a torrent of new imaginativeness as if opening some mysterious floodgate. Migraine and epilepsy auras may have influenced a long list of artists, including, some scholars speculate, Pablo Picasso, Vincent van Gogh, Giorgio de Chirico, Claude Monet, Georges Seurat and Lewis Carroll. Traumatic brain injury can result in original thinking and newfound artistic drive. Emergent creativity is also an occasional feature of Parkinson's disease.

This burst of inspiration is especially true of frontotemporal dementia (FTD). Although a few rare cases of FTD are linked to improvements in verbal creativity, such as greater poetic gifts and increased wordplay and punning, enhanced creativity in the visual arts is an especially notable feature of the condition. This fascinating side effect indicates that the potential to create may rest dormant in some of us, only to be unleashed by a disease that also can cause a loss of verbal abilities.

Emergence of a vibrant creative spark in the face of devastating neurological disease speaks to the human brain's remarkable potential and resilience. A study published in JAMA Neurology by researchers at several institutions, including the University of California, San Francisco, examines the roots of this phenomenon and provides insight into a possible cause. Neurologist Adit Friedberg of U.C.S.F. and her colleagues found that as specific brain areas diminish in people with FTD, they release their control of other regions that support artistic expression.

FTD is relatively uncommon—affecting about 60,000 people in the U.S.—and is distinct from Alzheimer's, the far more prevalent form of dementia in which memory deficits predominate. FTD is named for the frontal and temporal lobes of the brain, the two regions that sustain the most damage from this disease. Not every person with FTD has the same pattern of neuron loss in these areas; there are several variants. For example, degeneration in the temporal lobes, which are the seat of language in the brain, leads to difficulties in producing and understanding written and spoken communication. Some people have impaired speech production; others may have trouble understanding word meanings.

People with FTD also experience degeneration in the frontal lobes, which typically engage in a suite of functions related to social behavior, empathy, planning and decision-making. Impairment there can lead to poor judgment and difficulty understanding the perspectives of others. The frontal lobes are involved in the complex interplay of brain areas that supports our social behavior, helping to balance baser desires and urges with an understanding of social norms and morals. In a healthy brain, the frontal lobes' activity can inhibit activity in other regions. This interchange is how the brain counters, for instance, the impulse to use rude language with the recognition that such responses can cause offense. Researchers suspect that in those with FTD, damage to the frontal lobes impairs the ability to suppress other brain activity, and their behavior becomes disinhibited and socially inappropriate.

The JAMA Neurology study suggests that, in a similar way, the loss of temporal lobe activity somehow disinhibits artistic creativity in some individuals. The researchers reviewed the medical records of 689 people with FTD or related disorders, looking for evidence of new or significantly increased or altered artistic expression. In total, they found this change in 17 people—2.5 percent of their participants. Most of these individuals painted, although some drew, sculpted, made pottery, crafted jewelry or quilted. FTD can sometimes be linked to certain genes, but no genetic cause of FTD was identified in this group. Most in this artistic group had forms of FTD in which language impairment was predominant, suggesting that FTD significantly affected their temporal lobes.

Researchers then selected people to compare with this artistic group. One set included FTD patients who were similar to the artists in many ways (including their diagnosis, age and sex) but did not exhibit an emergence of visual artistic creativity. An additional group matched the artists demographically (in age, sex, education, and other factors) but did not have any form of dementia or other serious health concern.

The research team used magnetic resonance imaging to examine the brains of the people in these three sets. Significantly, the scans revealed that people with FTD had reduced volume in their left temporal lobe—an area important for speech production—compared with that of healthy individuals. The atrophy was more pronounced in the artistic group than in those without artistic tendencies.

The scientists also found that some brain areas were more active when there was less activity in other areas. In particular, healthy people with less activity in the temporal lobe regions affected by FTD had more activity in their dorsomedial occipital lobe, a region involved in visual association. This finding implies that impairment of the temporal lobes by FTD could enhance this visual area. Further, among the visual artists with FTD, the greater the volume of the dorsomedial occipital lobe, the greater the volume of the portion of the motor cortex that controls movement in the right hand.

Taking the evidence together, the researchers concluded that this disease's effects on the temporal lobe may result in less control over the brain region that generates visual associations. In consequence, the creative drive is unleashed. Meanwhile the increased volume of the brain area that controls the right hand might reflect the use of that hand in creating art.

The researchers tested these ideas by observing brain changes in one person as her FTD progressed and creativity emerged. Positron-emission tomography scans measured the amount of energy being used by different regions of her brain. The scans revealed that as the woman's dementia progressed, her frontal and temporal lobes became significantly less active—and the areas involved in visual association became more active.

The study suggests that in a healthy brain, the temporal lobe directly or indirectly inhibits activity in the dorsomedial occipital lobe, which supports visual association. But why would a part of the brain involved in verbal processing suppress visual regions? From these findings, we can infer a reciprocal or even competitive relation between our verbal abilities and visual artistic creativity.

This insight is at the heart of a hypothesis regarding how our brain has changed over the course of human evolution: the superior visual perception hypothesis. Vision demands a lot of our brain's computational capacity—so much that we often close our eyes to concentrate on what we hear, whether it is music, speech, birdsong or crashing waves. According to the evolutionary hypothesis, when our species first began to develop language, the brain diverted computational capacity from visual processing to bolster this new activity.

For example, visual processing helps us comprehend gesture, a nonverbal form of communication that probably preceded our use of verbal language. Computational tasks that supported the production and interpretation of gesture were also relevant to speech, and so as we became more adept at language, gesture lost its primacy in communication. The brain regions responsible for gesture could have been taken over by those used in speech through an evolutionary process called exaptation, wherein parts of an organism take on different or completely novel roles.

This hypothesis may explain why areas involved in verbal processing might somehow tamp down activity linked to visual thinking. The FTD research suggests this evolutionary process is, in a sense, undone in the artists with dementia.

Brain injury and neurodegenerative disease often have tragic consequences. It is therefore remarkable that these conditions can have a seemingly positive effect such as enhanced creativity—and this finding can help us understand the origins of innovation. Creativity is part of humanity's essence and distinguishes us in some ways from our hominin relatives. Is it possible that an artist is hidden in each of us, awaiting an accidental emergence?

Creativity is a complex behavior that requires several elements, including the capacity for divergent and symbolic thought, persistence despite uncertainty, skill in execution and the ability to evaluate one's creations. When considering the burst in artistic activity sometimes seen in people with FTD, all these factors should be weighed. In general, patients with FTD perform poorly on tests of divergent thinking, suggesting either that the subset of people with the condition who become artists is quite distinct from others who have it or that different aspects of creativity are somehow enhanced in the FTD artists. Other studies have found that aesthetic judgment is retained in FTD, allowing affected people to evaluate the strength of their finished artwork, although many struggle to recognize emotional content in visual art.

Past research has also demonstrated that creativity emerges when we limit our self-critical thinking. In those with FTD, a lack of self-censorship may contribute to socially inappropriate behavior, for example, but it might also mean an artist's “inner critic” is less vocal. Yet another facet of artistic success is practice. FTD is often accompanied by perseverative behavior in which people repeat the same actions or statements or become mentally stuck in an idea or behavior. Some scientists have proposed that the FTD artist benefits from the combination of behavioral disinhibition and repetitive practice. Indeed, that could also help explain the literary output of poetic people with FTD, who, unlike visually artistic people with the condition, have been spared significant losses to the temporal lobes' language areas.

Still, none of these ideas fully explains the flourishing of creative behavior in some people with FTD. The authors of the JAMA Neurology study emphasize that the FTD artists were only a small percentage of the total number of people with this dementia in their study group. Other factors, such as an artistic predisposition and circumstances or an environment conducive to creative pursuits, may be important.

The FTD artist may help us understand creativity. Studies of such individuals can reveal the subtle interplay among brain regions that manifests in remarkable behaviors. The complexity of creativity makes it even more incredible that such ability can be a consequence of neurodegeneration. Ultimately these findings are a humbling reflection of the human brain's adaptability and seemingly endless capabilities.

Are you a scientist who specializes in neuroscience, cognitive science or psychology? And have you read a recent peer-reviewed paper that you would like to write about for Mind Matters? Please send suggestions to Scientific American’s Mind Matters editor Daisy Yuhas at pitchmindmatters@gmail.com.

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