Sunday, February 21, 2010

Your Brain on Music is a Highly Distributed Processor

BBC Science Reporter Victoria Gill in currently in San Diego covering the annual meeting of the American Association for the Advancement of Science. After yesterday's proceedings she filed a story that almost immediately grabbed my attention. Here is the opening summary:

Teaching stroke patients to sing "rewires" their brains, helping them recover their speech, say scientists.

By singing, patients use a different area of the brain from the area involved in speech.

If a person's "speech centre" is damaged by a stroke, they can learn to use their "singing centre" instead.

The paper was delivered by Gottfried Schlaug, Professor of Neurology at Harvard Medical School, practicing at Beth Israel Deaconess Medical Center. The research has been based on a therapeutic technique for stroke patients that has been used for some time. It is based on the premise that the brain has separate areas for processing speech and music. The conclusion of the above excerpt reasons that, if the patient cannot use language through speaking, linguistic performance may still be exercised through singing.

Not only is this principle familiar, it has led to any number of jokes. Had Figaro decided to ask Susanna about the price of the ribbons on her new little hat, one might have ended up with an elaborate duet (of a sort that only Wolfgang Amadeus Mozart could have composed) debating the equally elaborate fine points of the cost of living in seventeenth-century Seville! More seriously, Schlaug's contribution has escalated the study of the stroke-afflicted brain from a successful therapeutic technique to new results in brain imaging. His claim is that he can show "what is actually going on in the brain" (his words) as patients learn to sing their words rather than speak them.

More interesting for me, however, was a reaction Gill reported from another research community:

Dr Aniruddh Patel from the Neurosciences Institute in San Diego, said the study was an example of the "explosion in research into music and the brain" over the last decade.

"People sometimes ask where in the brain music is processed and the answer is everywhere above the neck," said Dr Patel.

"Music engages huge swathes of the brain - it's not just lighting up a spot in the auditory cortex."

Again, there has been talk about the brain as a distributed processor for some time. This inspired the whole connectionist approach to artificial intelligence that was so popular 25 years ago and probably still has its allotment of die-hard supporters. Connectionism never progressed very far beyond serving as a new approach to applying optimization to pattern classification, which is only a small part of what probably occupies "your brain on music" (to appropriate the turn of phrase by Daniel J. Levitin). The practice of music is a far more complex behavior, and researchers like Patel may be leading us into intricacies of brain function that could be only vaguely hinted in Levitin's exposition.

Needless to say, we are still quite some distance from any understanding of music behavior that accounts for the objective, subjective, and social worlds in any remotely comprehensive way. The good news from Professor Schlaug is the imaging technology keeps getting better; and, each time it improves, researchers come up with new ways to leverage those improvements. As we proceed down this path, there will be less talk about the "musical brain" at cocktail parties and more talk at scientific conferences!

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