Brain scans of jazz musicians unveil language and music similarities

Jazz fans will know that a defining characteristic of the genre – whose greats include Miles Davis, John Coltrane and Charles Mingus – are the spontaneous “musical conversations” that spark up when members of a jazz band improvise.

This improvisation bears similarity to human speech, with the players often taking it in turns to trade lines that build up into a dialogue.

Now, researchers at Johns Hopkins University in Baltimore, MD, have found that the brain interprets music and language in a similar way, by scanning the brains of improvising jazz musicians.

Eleven “highly proficient” jazz piano players, who were aged 25-26 and were all male, were recruited by the Johns Hopkins researchers.

Each musician would spend 10 minutes inside a magnetic resonance imaging (MRI) machine while engaged in a musical improvisation. The researchers would then analyze the MRI scans to see which brain areas were activated during the improvisation.

“Until now, studies of how the brain processes auditory communication between two individuals have been done only in the context of spoken language,” says Dr. Charles Limb, the senior author of the study, which is published in the journal PLOS ONE.

“But looking at jazz lets us investigate the neurological basis of interactive, musical communication as it occurs outside of spoken language.”

‘Trading fours’

The kind of improvisations in the study involve several musicians passing musical ideas back and forth and are known as “trading fours,” due to each improvised idea lasting for 4 bars. In each exchange, typically the musicians will introduce spontaneous new melodies in response to each other’s musical ideas.

The musician in the MRI machine would play on a specially designed plastic piano keyboard (containing no metal that would interfere with the MRI scan) while lying on his back, with mirrors placed inside the machine so the player could see where his fingers were placed on the keyboard.

Analyzing the results of the MRI scans, Dr. Limb and colleagues found that – while improvising – the areas of the musicians’ brains linked to syntax and language processing were activated. These areas are called “the inferior frontal gyrus” and “the posterior superior temporal gyrus.”

Interestingly, “the angular gyrus” and “the supra marginal gyrus” – areas of the brain involved in semantic processing – became deactivated during the improvisation sessions.

Brain interprets music as syntax rather than semantics

This suggests that the regions of the brain responsible for processing syntax are not just limited to spoken language. Instead, Dr. Limb argues, the brain uses its syntactic regions to process communication in general – whether that communication is through spoken language or music.

“We’ve shown in this study that there is a fundamental difference between how meaning is processed by the brain for music and language,” says Dr. Limb, who is a keen musician himself. “Specifically, it’s syntactic and not semantic processing that is key to this type of musical communication. Meanwhile, conventional notions of semantics may not apply to musical processing by the brain.”

“When two jazz musicians seem lost in thought while trading fours, they aren’t simply waiting for their turn to play. Instead, they are using the syntactic areas of their brain to process what they are hearing so they can respond by playing a new series of notes that hasn’t previously been composed or practiced.”

In 2012, Medical News Today reported on a study that used music to challenge established theories on right- and left-brain functions.

Written by David McNamee

http://www.medicalnewstoday.com/articles/273060.php

 

 

Stress can make the brain more susceptible to mental illness

Experts already know that people suffering from chronic stress are prone to experiencing mental health problems – such as anxiety and mood disorders – later in life. Now, a new study from researchers at the University of California, Berkeley, explains why.

Previous research has shown that people with post-traumatic stress disorder (PTSD) and other stress-related conditions have abnormalities in the brain.

The human brain is made up of “gray matter” and “white matter” and scientists have noticed that the proportions of white versus gray matter is different in people with stressillnesses, compared with other people. But so far, scientists have not been able to explain why these differences in the brain occur.

White matter gets its name from the white, fatty “sheath” of myelin coating it – the electrically insulating layer that forms around nerves and accelerates the transmission of electrical signals between cells. The new study focused on cells in the brain that produce myelin – the electrically insulating layer that forms around nerves.

Too much white matter

The researchers found that an excess of white matter is found in some areas of the brain in people who experience chronic stress. It seems that the experience of chronic stress causes more myelin-producing cells to be generated, with fewer neurons than normal.

The consequence of this is that the excess of myelin causes the “delicate balance” of the brain to be disrupted, with communication between brain cells slipping out of their normal timing.

To see how this happens, the researchers conducted tests on the hippocampus region in the brains of adult rats. But they found that the neuralstem cells in the rats’ hippocampi behaved in unexpected ways.

Previously, it was thought that these stem cells would only mature into neurons, or a type of cell called an astrocyte. However, when the rats were experiencing chronic stress, these stem cells matured into another form of cell – an oligodendrocyte. Oligodendrocytes are the cells that produce myelin.

As well as producing the myelin in white matter, oligodendrocytes also aid the formation of synapses – the structures that allow nerve cells to connect and exchange information with each other.

Could stress cause changes in brain connectivity?

The researchers wonder if people with PTSD undergo changes in brain connectivity. For instance, if their hippocampus (which regulates memory and emotions) might develop a stronger connection to their amygdala (where the “fight or flight” response is processed).

This theory could also mean that PTSD patients might have weaker connectivity between the hippocampus and the prefrontal cortex, which moderates our responses.

“You can imagine that if your amygdala and hippocampus are better connected, that could mean that your fear responses are much quicker, which is something you see in stress survivors,” says study author Prof. Daniela Kaufer.

She adds:

“On the other hand, if your connections are not so good to the prefrontal cortex, your ability to shut down responses is impaired. So, when you are in a stressful situation, the inhibitory pathways from the prefrontal cortex telling you not to get stressed don’t work as well as the amygdala shouting to the hippocampus, ‘This is terrible!’ You have a much bigger response than you should.”

Prof. Kaufer and her team are conducting further investigations to test this hypothesis.

Because chronic stress is known to also affect memory and learning ability, Kaufer and her team think that this may be accounted for by the rat stem cells maturing into myelin-producing cells rather than the neurons that process and transmit the electrical information necessary for learning and memory skills.

In 2012, Medical News Today reported on a study that found it may be possible to identify people who could be susceptible to PTSD by analyzing scans of their brain.

http://www.medicalnewstoday.com/articles/272703.php

 

 

Picture courtesy of mdhomehealth.com