Tuesday, December 6, 2011

Your Brain on Improv by Dr. Charles Limb

Your Brain on Improv by Dr. Charles Limb


In this video, Dr. Charles Limb explains that it is possible to scientifically explain how brain activity relates to music-making. Using functional magnetic resonance imaging (fMRI), it is possible to obtain blood oxygen level-dependent (BOLD) imaging of active areas of the brain. When an area of the brain is active, blood flow increases in that area; that blood flow causes change in the concentration of deoxyhemoglobin. This change in deoxyhemoglobin content can be detected by BOLD-fMRI, and thus it is possible to determine which parts of the brain are more or less active depending on the amount of blood flowing through them. Dr. Limb summarizes his findings by showing three experiments, in which the subjects were asked to either improvise or perform a memorized melody or a text.

First experiment. During the fMRI, subjects (all jazz performers) were required to either play a memorized melody or improvise a new one on a MIDI keyboard connected to a computer. Both memorized and improvised melodies were played over the same harmonic progressions. The resulting BOLD-fMRI contrast maps showed that some areas of the brain are activated and others de-activated when the subjects are improvising versus when they are playing memorized melodies. The study results showed that when improvising, the area of self-monitoring turned off while the autobiographical or self-expressive area turned on. A hypothesis made by Dr. Limb is that being creative implies that one area of the frontal lobe goes up in activity, and another down.
In the second experiment, the subjects were asked to improvise. The results showed that the activity in Broca's area (usually associated with language) increased. Dr. Limb suggested that there might be a neurologic basis for the notion of music as a language.
In the third experiment, the subjects were asked to either memorize or improvise a rap over some cue words. In both cases, improvisation and language areas were activated. When free-styling with closed eyes, visual areas and major cerebellar-motor coordination activity was activated.


The video offers an overview of some important issues related to brain activity in music-making and music creativity. I was particularly interested in the concept highlighted by Dr. Limb that musical creativity might entail the simultaneous activation of certain areas of the brain and de-activation of others, as a mechanism to prevent the interference of inhibitions during the creative process. This seems to suggest that, in solo piano jazz improvisation (we did not see any other types of instrumental interaction or ensemble situation in the experiments), the brain recognizes and classifies rhythmic and melodic patterns as either known or new, and reacts accordingly by activating or shutting down certain areas. However, improvisers do not “invent” music; they have the ability to combine, in a strikingly short time span, a multitude of melodic and rhythmic patterns, and harmonic progressions that are already known to them. I wonder whether, by using the word creativity, Dr. Limb intends to describe this fast combination of memorized patterns, or a more inclusive activity that includes factors not highlighted in the experiment. This point remains slightly unclear to me.

In the third experiment, I found it interesting that free-styling with closed eyes activates both visual and coordination areas of the brain, on top of language areas. As for most performers, for free-styling rappers too visualizing one’s own body seems an important element. I wonder whether the activation of these areas during free-styling is related to the practice of improvisation or whether it has more to do with the lack of sight. As a performer, I find it useful to visualize my body perform at the keyboard, as this helps me to acquire precision and to have a more secure approach to the instrument.

1 comment:

Amber Cunningham said...

Improvisation vs. Memorization is a particularly intriguing topic in the scope of neurological research. I too have often wondered at the activation of the visual cortex during performance. You raise a good point that visualization of one's body is a common and helpful technique among performers. I often break down musical patterns and associate them with a visual shape or colour to clarify my musical intentions. In performing both classical (memorized) and jazz (a combination of memorized and improvised) repertoire I have found this visualization useful. In jazz in particular I agree that improve is really more syntax than true improve. I also use this "geometric" visualization when constructing a phrase quickly. I visualize the shape I want and fill in from my vocabulary of patterns. Perhaps this is another possible explanation for the visual cortex to be stimulated?