28 February 2008

This Is Your Brain On Jazz

by Kate Melville

Using functional magnetic resonance imaging (fMRI), two scientists have discovered that when jazz musicians improvise, their brains turn off areas linked to self-censoring and inhibition, and turn on those that let self-expression flow. The joint research, using musician volunteers from the Johns Hopkins University's Peabody Institute, sheds light on the creative improvisation that artists and non-artists use in everyday life, the researchers say.

Reporting their findings in Public Library of Science (PLoS) ONE, the scientists, from the Johns Hopkins University's School of Medicine and the National Institute on Deafness and Other Communications Disorders (NIDCD), describe their curiosity about the possible neurological underpinnings of the almost trance-like state jazz artists enter during spontaneous improvisation.

"When jazz musicians improvise, they often play with eyes closed in a distinctive, personal style that transcends traditional rules of melody and rhythm," says Johns Hopkins' Charles J. Limb. "It's a remarkable frame of mind, during which, all of a sudden, the musician is generating music that has never been heard, thought, practiced or played before. What comes out is completely spontaneous."

Though many recent studies have focused on understanding what parts of a person's brain are active when listening to music, Limb says few have actually delved into brain activity while music is being spontaneously composed. Curious about his own "brain on jazz," he and a colleague, Allen R. Braun, of NIDCD, devised a plan to view in real time the brain functions of musicians improvising.

For the study, they recruited six trained jazz pianists and designed a special keyboard to allow the pianists to play inside a fMRI machine. Because fMRI uses powerful magnets, the researchers designed the unconventional keyboard with no iron-containing metal parts that the magnet could attract.

After recording baseline brain scans while the subjects played scales and memorized pieces of music, Limb and Braun then analyzed the brain scans as the musicians improvised their own tunes. Since the brain areas activated during memorized playing are parts that tend to be active during any kind of piano playing, the researchers subtracted those images from ones taken during improvisation. Left only with brain activity unique to improvisation, the scientists saw strikingly similar patterns, regardless of whether the musicians were doing simple improvisation on the C-major scale or playing more complex tunes with the jazz quartet.

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. "Jazz is often described as being an extremely individualistic art form. You can figure out which jazz musician is playing because one person's improvisation sounds only like him or her," says Limb. "What we think is happening is when you're telling your own musical story, you're shutting down impulses that might impede the flow of novel ideas."

Limb notes that this type of brain activity may also be present during other types of improvisational behavior that are integral parts of life for artists and non-artists alike. For example, he notes, people are continually improvising words in conversations and improvising solutions to problems on the spot. "Without this type of creativity, humans wouldn't have advanced as a species. It's an integral part of who we are," Limb says.

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Source: The Johns Hopkins University