Not Exactly Rocket Science

You're lying face-up with your head surrounded by a large medical scanner. You've been told that you have to keep your head completely still. You can't look down to see your hands and you can't hear very much beyond the background hum of the machine. A perfect time for some improvisational jazz then....

This was the challenge posed to six professional jazz musicians by Charles Limb and Allen Braun from the National Institute on Deafness and Other Communication Disorders. They were told to play that funky music while undergoing fMRI (functional magnetic resonance imaging), a brain-scanning technique that would enable the two researchers to quite literally see the creative process in action.

Scanning the creative mind

Improvisation is the cornerstone of great jazz performances, and it is a joy to watch musicians deftly adapting pieces of music on the fly to create something familiar yet wholly original. To Limb and Braun, this skill is a fine example of the creative process, itself a "quintessential feature of human behaviour".

The duo approached their study with the assumption that there is nothing mystical or obscure about creativity. Like all other matters of the mind, it is the result of firing neurons, a tangible process that we can understand and even see in action. That's where the fMRI came in, but getting someone to play properly within such restrictive confines is challenging to say the least.

To do it, Limb and Braun ordered a special, custom-built piano keyboard, that lacked any metallic parts that would be affected by the scanner's powerful magnets. Each musician lay down in the scanner with their knees up and the keyboard in their laps. An angled mirror positioned over their eyes allowed them to see the keys, and a small earpiece allowed them to hear what they were playing.

In the 'Scale' task, the musicians were either asked to repeatedly play the simple C major scale within one octave, or to play an improvised melody of their choice using only the same nine notes. This was a fairly basic form of improvisation and Limb and Braun also wanted to capture the much richer nature of true jazz performances.

In the more complicated 'Jazz' task, they were first asked to learn an original jazz composition. Once in the scanner, they either had to play the unaltered tune, or to improvise freely, using the chord structure of the new piece as a guide. In both cases, they listened to a pre-recorded accompanying quartet, which they could use as inspiration during the improvisational phase.

The musicians showed very similar patterns of brain activity during both the Scale and Jazz experiments, despite the different degrees of difficulty. In both cases, certain parts of the brain were consistently activated during improvisation, while others were consistently turned off. In the image below, the red areas represent bits which are more strongly activated when improvising, and the blue areas are bits that are comparatively turned off.

What improvisation looks like

The prefrontal cortex, which controls many of our higher mental abilities from planning to problem-solving, was particularly strongly affected. Large swathes of it were completely shut down, including the LOFC (lateral orbifrontal cortex), which monitors and blocks out inappropriate behaviours, and the DLPFC (dorsolateral prefrontal cortex), which is involved in planning and focused, methodical thinking.

These widespread deactivations could help musicians to avoid over-thinking a task. By turning off parts of the brain involved in self-assessment and focused attention, they could pave the way for actions and ideas that are spontaneous, unplanned and new.

Within the large prefrontal cortex, only one area was strongly activated during improvisation - the medial prefrontal cortex (MPFC). Recent studies have suggested that the MPFC plays a role in our sense of self, and it certainly lights up when people recount personal anecdotes. To Limb and Braun, its heightened activity fits with the idea that musicians use improvisation as an outlet for expressing their own musical voice and experiences.

The fMRI images also revealed that when improvising, the musicians' brains showed more activity in areas involved in hearing, sight and touch, even though they were seeing, touching and hearing much the same things as they were when playing from memory. Their improvised pieces were no faster than the originals nor did they include more notes. Instead, Limb and Braun suggest that during the creative state, a musician's senses are heightened across the board.

The scans imply that there is a very consistent pattern of brain activity linked to creativity, a pattern of heightened senses and self-expression with a lack of conscious control. And the very similar results from the Scale and Jazz scans suggest that this has nothing to do with the complexity of the music and everything to do with the creativity of the performers.

Limb and Braun also tantalisingly suggest that a similar prefrontal shut-down could also be linked to other states of altered consciousness including meditation, hypnosis and most intriguingly, dreaming.

Reference: Limb, C.J., Braun, A.R., Greene, E. (2008). Neural Substrates of Spontaneous Musical Performance: An fMRI Study of Jazz Improvisation. PLoS ONE, 3(2), e1679. DOI: 10.1371/journal.pone.0001679

For more on the psychology of music, have a look at this post from the classic sight about how music sounds right because it reflects the hidden tones in our speech.

Image of jazz pianist by biskuit

(Mo from Neurophilosophy has also written about this paper but I really couldn't resist doing my own take. It's just such an awesome study)