New York: Emotional expression affects the brain's creativity network, says a new brain-scanning study of jazz pianists, adding that “happy” and “sad” music evoked different neural patterns in their brains. The workings of neural circuits associated with creativity are significantly altered when artists are actively attempting to express emotions, the researchers report. “The bottom line is that emotion matters. It can't just be a binary situation in which your brain is one way when you're being creative and another way when you're not,” said senior author Charles Limb from University of California-San Francisco. “Instead, there are greater and lesser degrees of creative states, and different versions. And emotion plays a crucially important role in these differences,” he explained. The team focused in a brain region known as the dorsolateral prefrontal cortex (DLPFC), which is involved in planning and monitoring behaviour. The researchers found that DLPFC deactivation was significantly greater when the jazz musicians improvised melodies intended to convey the emotion expressed in a "positive" image (a photograph of a woman smiling) than a "negative" image (photo of the same woman in a mildly distressed state). On the other hand, improvisations targeted at expressing the emotion in the negative image were associated with greater activation of the brain's reward regions. “This indicates there may be different mechanisms for why it's pleasurable to create happy versus sad music,” added first study author Malinda McPherson. For each musician, any brain activity data generated during these passive viewing periods, including emotional responses, were subtracted from that elicited during their musical performances. This allowed the researchers to determine which components of brain activity in emotional regions were strongly associated with creating the improvisations. Moreover, Limb said, the research team avoided biasing the musicians' performances with words like "sad" or "happy" when instructing the musicians before the experiments. The paper appeared in the journal Scientific Reports.