Mind Hacks pointed me to an interesting study by science journal PLoS One on the cognitive neuroscience of Jazz.
The scientists found that a region of the brain known as the dorsolateral prefrontal cortex, a broad portion of the front of the brain that extends to the sides, showed a slowdown in activity during improvisation. This area has been linked to planned actions and self-censoring, such as carefully deciding what words you might say at a job interview. Shutting down this area could lead to lowered inhibitions, Limb suggests.
The researchers also saw increased activity in the medial prefrontal cortex, which sits in the center of the brain’s frontal lobe. This area has been linked with self-expression and activities that convey individuality, such as telling a story about yourself.