https://www.statnews.com/2023/08/10/dementia-ftd-rare-visual-creativity-painting/

Frontotemporal dementia

“If neurodegeneration begins on the right side of the frontal or temporal lobes, patients tend to struggle with compulsive or inappropriate behaviors and emotional regulation. These symptoms include loss of empathy for others, disregard toward social and legal norms, loss of drive, overeating, and repetitive behaviors like tapping a pencil incessantly.

But if it starts on the left side, patients have difficulty with understanding and communicating language. They lose the meaning of words, leading them to speak nonsensical gibberish, or lose the ability to form words, making it difficult to converse.

As the disease progresses, behavioral and linguistic symptoms eventually overlap.”

The many sides of the brain.