In this interesting paper from the NIH, researchers found that when jazz musicians improvised or made a spontaneously creative musical phrase using a MIDI keyboard, they deactivated large areas of their prefrontal (planning, attention) and limbic (emotions)cortices, and activated their sensory and motor areas. In this paradigm, then, creativity is the result of both negative and positive forces.
Some interesting implications come to mind - previous work on the coincidence of ADHD symptoms and creativity, the finding of delayed prefrontal development among children with superior IQ, and even the dichotomy between deductive / analytical and inductive / intuitive creative thinking.
From the perspective of the brain, we were also struck by the front vs. back pattern of deactivation & activation (conscious vs. subconscious, planned vs. unplanned) that improvisation requires. Jazz improvisation is immediate (unplanned) and musicians often say they feel more than think the music. This front-back pattern may underlie other forms of kinesthetic creativity that require quick / immediate on-the-spot problem solving, like the type you find great surgeons or crisis / rescue experts.
It also points out the folly of simply trying think creative. In fact, many of the techniques touted by corporate creativity trainers seem to be geared toward activating and retrieving possibilities that are decidedly not consciously determined.
PLoS ONE: Neural Substrates of Spontaneous Musical Performance: An fMRI Study of Jazz Improvisation
Eide Neurolearning Blog: Smart, But Underachieving: Knowledge, Creativity...
Coincidence of Attention Deficit Disorder with Hyperactivity and Creativity
Creative and Analytical Thinkers Differ in Their Use of Attentional Resources pdf