A pair of Johns Hopkins and government scientists has
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 functional magnetic
resonance imaging and musician volunteers, sheds
light on the creative improvisation that artists and
nonartists use in everyday life, the investigators
say.
In a report published Feb. 27 in PLoS ONE, the
two scientists describe their curiosity about
the possible neurological underpinnings of the almost
trancelike 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,"
said Charles J. Limb, assistant professor in
the Department of Otolaryngology-Head and Neck Surgery at
the Johns Hopkins School of Medicine
and a trained jazz saxophonist himself. "It's a remarkable
frame of mind," he said, "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 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 the National
Institute on Deafness and Other Communication Disorders,
devised a plan to view in real time the
brain functions of musicians improvising.
For the study, they recruited six trained jazz
pianists, three from the university's Peabody
Institute, where Limb holds a joint faculty appointment,
and others who had learned about the project
by word of mouth through the local jazz community.
The researchers designed a special keyboard to allow
the pianists to play inside a functional
magnetic resonance imaging machine, a brain-scanner that
illuminates areas of the brain responding to
various stimuli, identifying which areas are active while a
person is involved in some mental task, for
example.
Because fMRI uses powerful magnets, the unconventional
keyboard has no iron-containing metal
parts that the magnet could attract. They also used
fMRI-compatible headphones that would allow
musicians to hear the music they generate while they were
playing it.
Each musician took part in four different exercises
designed to separate out the brain activity
involved in playing simple memorized piano pieces and
activity while improvising their music.
While lying in the fMRI machine with the special
keyboard propped on their laps, the pianists
began by playing the C-major scale, a well-memorized order
of notes that every beginner learns, in
time with a metronome playing through their headphones. In
the second exercise, the pianists
improvised in time with the metronome. They were asked to
use quarter notes on the C-major scale
but could play any of these notes that they wanted.
Next, the musicians were asked to play an original
blues melody they had memorized, while a
recorded jazz quartet that complemented the tune played in
the background. In the last exercise, the
musicians were told to improvise their own tunes with the
same recorded jazz quartet.
Limb and Braun then analyzed the brain scans. 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 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 one 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
oneself.
"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," Limb said.
"What we think is happening is [that] 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 nonartists alike. For example,
he notes, people are continually improvising words in
conversations and 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 said.
He and Braun plan to use similar techniques to see
whether the improvisational brain activity
they identified matches that in other types of artists,
such as poets or visual artists, as well as
nonartists asked to improvise.
This research was funded by the Division of Intramural
Research, National Institute on
Deafness and Other Communication Disorders, National
Institutes of Health.
GO TO