Monday, November 10, 2008

Article 5-...Study of Jazz Improvisation, Article 6...comparison of the human corpus callosum in professional musicians and non-musicians..

University of Toronto
Course: MUS 2122H: Music and the Brain - Fall 2008
Instructor: Dr. Lee Bartel
Student: Maddie

Portfolio: reference, review, reflect and report.


Article 5:
Neural Substrates of Spontaneous Musical Performance: An fMRI Study of Jazz Improvisation.
by Charles J. Limb and Allen R. Braun
PubMed Central, Journal, February 27, 2008
PLoS ONE 3(2): e1679. doi:10.1371/journal.pone.0001679

Article 6:
Morphometric comparison of the human corpus callosum in professional musicians and non-musicians by using in vivo magnetic resonance imaging.
by A. Hakan Ozturk, B. Tasçioglu, M. Aktekin, Z.Kurtoglu and I.Erden
American Journal of Neuroradiology, March 2002, 29(1):29-34


Overall objective:
Examine the central mechanisms that give rise to music performance.

Immediate objective:
· Investigate the neural substrates that underlie spontaneous musical performance of
professional jazz pianists as they improvised using functional MRI.
· Provide insights into the neural correlates of the creative process.

1. “Spontaneous musical improvisation would be associated with discrete changes in
prefrontal activity that provide a biological substrate for actions that are characterized by
creative self-expression in the absence of conscious self-monitoring.”
2. “Alterations in prefrontal cortical activity would be associated with top-down changes in
other systems, particularly sensory areas needed to organize the on-line execution of
musical ideas and behaviors, as well as limbic structures needed to regulate memory and
emotional tone.”

Limb and Braun monitored the neural activity of six (6) highly skilled professional jazz musicians as they played an over-learned musical sequence and then, a spontaneous musical performance (improvisation), on the piano. “Both used musical control tasks designed to engage the same sensorimotor circuits but to generate pre-determined, over-learned output.”


Spontaneous improvisation:
· Activations of the prefrontal cortex.
· Increased activity in some to the sensory areas involved.
· Widespread attenuation of activity in limbic and paralimbic regions.

Controlled task:
· Activations during improvisation were matched by deactivations during the control task,
and vice versa.


While spontaneously improvising, there is:

1. Activation of the prefrontal cortex.

The lateral portion of the prefrontal cortex, the part of the musician’s brain that monitors performance (goal-directed behaviours, self-censoring, focused attention and inhibition) shuts down. This gives rise to “defocused, free-floating attention that permits spontaneous unplanned associations, and sudden insights or realizations.” At the same time, the medial prefrontal cortex, the part of the musician’s brain that organizes “self-initiated thoughts and behaviors, or self-expression, becomes highly activated.”

i. “This unique pattern may offer insights into cognitive dissociations that may be intrinsic to THE CREATIVE PROCESS: the innovative, internally motivated production of novel material that can apparently occur outside of conscious awareness and beyond volitional control.”
ii. “Creative intuition may operate when an attenuated DPFC no longer regulates the contents of consciousness, allowing unfiltered, unconscious, or random thoughts and sensations to emerge. Therefore rather than operating in accordance with conscious strategies and expectations, musical improvisation may be associated with behaviors that conform to rules implemented by the MPFC outside of conscious awareness.”
iii. “It has also been suggested that deactivation of the lateral prefrontal regions represents the primary physiologic change responsible for altered states of consciousness such as hypnosis, meditation or even daydreaming. This is interesting in that jazz improvisation, as well as many other types of creative activity have been proposed to take place in an analogously altered state of mind.”

2. Increased activity in some to the sensory areas involved.

This might be explained by “their role in processing complex stimuli in the auditory modality. However, increases in other sensory areas as well may be explained by “the intriguing possibility that musical spontaneity is associated with a generalized intensification of activity in all sensory modalities… or may be associated with encoding and implementation of novel motor programs that characterize spontaneous improvisation.”

3. Widespread attenuation of activity in limbic and paralimbic regions.

The deactivation of the amygdale and hippocampus was observed during improvisation.
This may be “attributable to the positive emotional valence associated with improvisation” and also because “during perception of music, that is consonant or elicits intense pleasure, thus shuts off the limbic structures.”


“Determine the possible morphometrical difference of the corpus callosum between professional musicians and non-musicians by using vivo magnetic resonance imaging (MRI)”.

Brain morphology is prone to plastic changes caused by environmental factors.

The corpus callosum is a large structure of fibres that connects the brain’s two hemispheres. Its function is thought to be “interhemispheric integration and communication”. And while the brain’s structure tends to change during growth, development and aging processes, some also think that environmental factors can also change it. In this study, researchers verified if training before brain development is complete could change the growth and development of the corpus callosum, and compared its anterior and posterior areas.

· Subjects were 20 20-year old professional right-handed string players who all received
musical training under the age of 9.
· Subjects included 20 non-musicians who were never professionally interested in music.
· All subjects underwent an MRI.
· All the lengths and thicknesses of the anterior and posterior areas of the corpus callosum
were measured.

There were significant differences between the two groups, both for the anterior and posterior areas of the corpus callosum.

· Significant differences in the thickness of the corpus callosum were found when they were
compared between the two groups.
· No significant differences were found when the lengths of the corpus callosum were
compared between the two groups.
· Significant differences in the area were again found for both the anterior and posterior of
the corpus callosum.

· “There is a size difference in the midsagittal area of the anterior half of the corpus
callosum between controls and professional classical musicians with an early
commencement of musical training.”
· There are no significant results in the posterior part of the corpus callosum between
musicians and controls.
· During the development of the CC, intense stimulation of the auditory cortices of
professional musicians could also play an important role in the determination of callosal
fibre composition and size in the posterior part of the CC.
· Chronic stimulation of the auditory cortices can be effective and cause plastic changes as
an adaptive structural-functional process in the posterior half.
· The corpus callosum can be manipulated by continuous sensory and motor stimulation,
such as seen in musicians who start training in early ages.
· “The changes are defined as plastic changes which are supported by animal and human

“There is a large variation in callosal size in different groups yet the significance is still being debated. Some recent suggested that larger callosal might indicate a higher capacity for interhemispheric transfer. Yet there are still many questions to be answered to provide conclusive results. It seems that it is still a question whether there is a specialized cortical network or whether it is gained by intensive training in musicians, or both. Brain morphology is prone to plastic changes caused by environmental factors.”


Since listening to music has the potential to heighten our experiences, as it can elicit strong positive emotions, I have often wondered if there were even greater rewards for those who learn to make music?

After reading the first article, it became clear that, in fact, the experience can be greater, especially when one considers that while improvising, the parts of the musicians’ brains that monitor their performance (self-censoring and inhibition) shut down, while the sections that organize “self-initiated thoughts and behaviors”, or self-expression, are highly activated.

How great is it to be able to shut off the dominant left brain and its rationality and allow the creative, imaginative and intuitive right brain, which promotes the free flow of novel ideas, impulses and self expression, those self-initiated thoughts and behaviours which convey individuality, to take over. Finally, through the study of music, we have perhaps found a way to provide serious insight into the creative and the intuitive processes, which have long been deemed too elusive to measure.

Further reflection brought me to review what, in fact, a musician must do to improvise. I‘ve gleaned that improvising in music entails “having to follow the basic structure of a given song while, on the fly, generate a new melody that picks up on and plays off of the individual performances of the other instruments”, all the while not forgetting the other tasks such as feeling the keys and moving the fingers to precisely orchestrate the movement between the right- and left-hand sides of the body, which are comprised of thousands of muscle fibres in the body. I concluded that improvising is multi-tasking at the highest level and involves many brain functions from both the left and right hemispheres.

To shut off the mechanism that monitors one’s self, it would be necessary for musicians to avoid sending negative signals to the brain as the amygdale would surely engage the survival mechanism and initiate the process of scrutinizing itself. Of course, playing music is associated with being a pleasurable activity, which helps in the process of shutting down the amygdale; however, I believe many other factors have to be in check if one is to stay in this positive frame of mind. One must assume that those musicians who are chosen are completely confident in their talent to achieve the task at hand, so to remove from awareness any worries, fears or anxiety they may have about the improvisation. If one is overwhelmed by the task, one will retract.

To ensure a calm, positive and focused state of mind, I believe that these musicians fully master their instrument. They must also fully understand music’s rules and patterns, enabling them to focus not on the mechanics involved in playing the instrument, but on their listening skills and the experience of the improvisational performance itself. If they don’t, the mechanics can break their concentration and hold them back from totally abandoning themselves to the process.

Isn’t it fascinating how musicians haven’t even begun to play their instruments and already need to invest a great deal of their psychic energy, along with the appropriate skills, to ensure that they remain in the right frame of mind, which will then allow them to turn on their right brain, or the creative self, as noted in the article, and shut off the logical mind. Could it be that they completely focus on a desire to create an amazing piece of music, to leave no room in their minds for irrelevant information? Could investing all of their psychic energy in the fulfilment of this goal be the key to deactivating the prefrontal lobe?

Having been involved in the creative process, I know that the challenge in accomplishing something novel certainly engages one’s attention to its fullest and allows one to forget the self and plunge into the art of doing. Could this unusual investment of attention on the task at hand be enough to alter one’s state of mind? I have concluded that the desire to achieve something unexpected is once again another condition to keep the left hemisphere out of the picture. That is, anything that deals with desires, emotions, images, impressions and intuition is ignored by the left hemisphere and delegated to the right hemisphere.

Is it a combination of all the aforementioned conditions that activate the creative process? Perhaps. However, experience has taught me that even though all the right (appropriate) conditions are present, one can never predict with any certainty when and if the creative flow will occur. So, what exactly do musicians do differently that allow them to enter the creative process as soon as an improvisation begins? Could it be music’s rhythmic power, making it possible to access the creative process at will? Or is it the intense physical nature of music that truly makes the difference? Or is it both? After all, the article did mention that sensory areas were activated and the gyri, which are functionally related to the initiation of voluntary movement, were so activated. In fact, music is so intensely physical that it has been proven to so affect our physiology that it can raise our pulse-rate, alter our respiratory rate and skin response, increase muscular tone and thereby influence our emotions and moods.
In retrospect, it was interesting to note that by listening to and concentrating on the different patterns of rhythmic sounds produced by the other musicians to recognize the order underlying the work, there was a “broad increase in sensorimotor activity”. One’s mind begins to partake in an intense sensory experience. Perhaps this heightening of the sensory processing produced by the sound patterns is what initiates the process to “encode and implement novel motor programs”, as suggested by the article. It can also perhaps predispose musicians to reach deeper into self-identity, enabling them to retrieve images upon which to improvise.

And as one responds by providing spontaneous graceful rhythms and harmonies which find their way into the nervous system, given the occurrence of heightened sensory processing, feelings are soon evoked, giving rise to a complete right hemisphere experience. This state can be maintained, because intense feelings are said to give rise to a flow of images in one’s consciousness, images coming from a deeper level of consciousness, thereby allowing one’s expression to be released.

Could this mean that to access any type of creative state at will or to access it more efficiently, assuming the right conditions, some kind of kinaesthetic and rhythmic involvement is needed to help organize or modify our brain’s circuits? How interesting! I will definitely pursue this thought. Furthermore, could these findings also reveal that music is capable in helping us understand the rules by which the brain changes its organization?

The second article certainly points in that direction as the researchers concluded that the corpus callosum, which is responsible for connecting the two hemispheres into a unitary consciousness, is bigger in musicians than in non-musicians because “the brain morphology is prone to plastic changes caused by environmental factors”. We learn the important rule that the brain changes its organization by responding to a person’s life experiences. In this case, the corpus callosum has changed as a result of early musical training, which strengthened neural connections. The significance of a bigger corpus callosum, as this article reveals, “is still being debated”. However, until further research is available, if one adheres to the premise that “a larger callosal area might indicate a higher capacity for interhemispheric transfer”, one might say that since each hemisphere controls movements on the opposite side of the body, rapid communication between the hemispheres would certainly help for coordinating fingering, especially for complex musical pieces.

The findings of the study support that “brain morphology is prone to plastic changes caused by environmental factors.” The bigger corpus callosum developed in musicians is certainly a positive change in the anatomy of the brain, if it can improve motor control by speeding up communication between the hemispheres. How interesting is it that our brain has the ability to change, because it responds to circumstances and to new learning? And, how curious is it, that as we seek to understand the rules by which the brain changes its organization to control these changes, which in turn will enable us to find remedies or cures for what we feel are brain malfunctions or abnormalities, which cripple one’s existence, we learn that the brain has the ability to change its organization and adapt to our changing needs?

To make sense of it all, one must remember that perhaps our greatest challenge lies not only in learning how the brain changes its organization, but also in trying to identify what brain mechanism we want to reinforce. And, as noted in the article, it is best to begin to implement these brain mechanisms as early as possible when the brain is most responsive. With this in mind, I feel there is hope in creating entirely new cultures.

At the same time, knowing that much of our experience is not directly accessible to our own thoughts and reflections, the brain being set up to use many of our experiences without allowing them to gain access to our consciousness, it is quite clear that we also need to learn more on how our consciousness functions to gain better insight into how we can better shape our world. Thoughts?

No comments: