When Victor quit his job as a lawyer at the practice he founded and moved in with his mother, his family suspected that something was amiss. For a man in his early 50s with no other job prospects, the decision just didn’t make sense. As described in a 2009 case study in the journal Neurocase, things only got stranger from there.

Victor became a compulsive coin collector, scavenging for loose change in the street or in other people’s bags. He stopped showering or using deodorant and took to wearing unwashed Hawaiian shirts and sandals. He spoke less and struggled finding words. Most surprising of all, he became a prolific artist, adorning canvases with richly colored portraits and creating lavish sculptures.

Victor was diagnosed with frontotemporal dementia, shrinkage of the brain’s frontal and temporal lobes. The second most common cause of early-onset dementia, it brings on personality change and a neglect of social decorum. With his diagnosis, he joined a growing cohort of patients for whom their dementia sparked newfound artistic potential. The connection was described as far back as the late 1990s by the neurologist Bruce Miller—and today, with modern neuroimaging techniques, researchers are beginning to discover how this disease might hold the keys to understanding creativity.

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There are several theories on the connection between dementia and artistry. The first involves the prefrontal cortex, contained within the frontal lobe, home of high-level analysis and planning. When the region is damaged in frontotemporal dementia, people stop filtering their behavior and let go of their inhibitions. In the absence of the prefrontal lobe’s self-monitoring, an underlying creative drive emerges.

Consider a poet engrossed in the process of composition. A 2015 study from the journal Human Brain Mapping shows that while she is “in the zone,” the lyrics flowing freely from her mind to her pen, the prefrontal cortex is partially deactivated. But when the poet begins to edit her piece, the prefrontal reignites. Similarly, jazz pianists use the prefrontal cortex less while improvising than they do while playing well-rehearsed pieces. Shutting down this region seems to lead to unchecked creative expression. In fact, many of Victor’s paintings were sexually suggestive, and his portraits of family and friends sometimes betrayed unflattering feelings about them. His loss of a filter from prefrontal damage was manifested not only in his socially inappropriate behavior but also in his artwork.

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