It’s hardly surprising that brain damage can change the way some people express themselves artistically. For people with Alzheimer’s, autism, or affected by stroke—three very different kinds of brain damage—the art may even get richer and more nuanced, or cleaner and simpler, depending on the effects of the disease, according to one Penn researcher.

Anjan Chatterjee, associate professor in the Center for Cognitive Neuroscience in the School of Medicine, believes analyzing the work of brain-damaged artists can offer insight into new ways to help patients with brain damage. To that end, Chatterjee—a photographer in his free time—recently compiled more than 50 years of articles and books on the subject and found that the artwork of brain-damaged artists is often vibrant and profound.

“The art can be really quite striking,” he says.

Chatterjee found the nature and subject matter of the art produced by these artists varies greatly, depending on the type of brain damage.

Chatterjee cites the case of J.J. Ignatius Brennan, a surrealistic painter who suffered from migraine headaches, who used zigzag shapes and clouds to symbolize his headache symptoms. Then there’s Willem de Kooning, an abstract expressionist painter known for his colorful, busy canvases, who was diagnosed with Alzheimer’s in the later 1970s. Chatterjee notes the comments of one museum curator who put together a show of de Kooning’s post-Alzheimer’s work in the 1980s—the curator praised de Kooning’s simple, clear lines and striking colors.

Artistic skills can also be remarkable in autistic people, says Chatterjee, who contrasts a “normal” six-year-old child’s drawing of a horse—a simple drawing with little detail—with a drawing of a horse by a three-year-old with autism. The latter is a realistic, detailed drawing that appears to have been done by a person with far more training.

But does this mean that artists can actually improve their craft after they become sick? Chatterjee believes that in some instances, they can, because the loss of special reasoning with some types of brain disease may actually allow an artist to use lines more expressively, rather than just descriptively. What is clear, he says, is that changes in the brain affect the art—which leads him to believe that art comes from a neurological place, rather than simply an emotional one.

All of this raises questions about the relationship of knowing and seeing, he says. “How much are you drawing what you’re looking at and how much are you drawing what you know?” he asks. Chatterjee concludes that continuing research of brain-damaged artists could lead to a greater understanding about the nature of artistic production.