Wednesday, 14 December 2011

A Lot More Than 10 Percent!

Have you ever heard that you only use 10% of your brain?  I don’t know where that idea came from, but it’s definitely wrong.  At any one time, you are using many, many parts of your brain at once, certainly more than 10%.  Even doing nothing activates circuits in brain known as the default mode network, which is most active when we are daydreaming, lost in space.  Only 10% of our brain?  That idea is completely bogus, as are a number of other things you think you know about the brain.

Listening to and playing music probably uses more of the brain at once than most other activities we engage in.  Research has shown that listening to music recruits a number of different areas of the brain.  However, it’s been tricky to tease apart which parts of the brain do exactly what in processing music, since it’s almost impossible to completely separate the different components that make up music.  And besides, if you try to whittle music down to a single component (i.e. rhythm or pitch or timbre), is what you’re left with really music?  Does the brain respond the same way to stylized lab-produced sounds as it would to a real musical excerpt?

A recent study from a Finnish research group has tried to answer these questions by combining computer-based acoustic feature extraction with fMRI analysis of people listening to a tango by Astor Piazzolla

The results support much of the research that has been reported in the past, in terms of which parts of the brain are activated by specific aspects of music – timbre, rhythmic pulse, key, etc.  But the findings also show that the areas activated are more widespread than previously thought, and there are also areas that are activated during music listening that didn’t seem to correlate with any of the features specifically studied.  What these parts of the brain are doing remains to be seen.  Also, and not surprisingly, listening to a real piece of music activated emotional centres of the brain more than in other studies using less naturalistic stimuli.

Timbre was found to activate widespread areas of temporal cortex, especially on the right side, as well as cognitive parts of cerebellum.  Music with complex timbre deactivates the default mode network, meaning that it grabs our attention and the parts of our brain that make our mind wander get turned off.

Interestingly, motor and somatosensory areas of brain were activated, even when just listening to music.  The subjects were all trained musicians, and it has previously been shown that listening to music can activate motor areas, as if we are unconsciously thinking about actually playing the music we hear.  The somatosensory areas may be activated due to mirror neuron activity.  These areas are activated when hearing sounds made by others’ actions.

Overall, it is clear from this study and from previous research that listening to music activates large brain-wide networks of neurons.  Performing music must activate even more of our brain:  areas for planning and controlling movements, somatosensory areas for bodily feedback, and visual cortex for reading music, at the very least.  No wonder musical training is so good for your brain:  it’s a like full-brain workout.

1 comment:

  1. It really feels like a full brain workout. I heard from somewhere that sight reading music is the most difficult thing for the brain to do. Can you verify that?