Stroke Patients Sing Their Way Back to Speech
–Also: Good News for Bad Singers (below)
By Leo Kretzner, San Diego, CA. February 21, 2010.
Taking systematic advantage of an ability known about for a hundred years, the speechless are learning to sing their words – and finding they come far more easily that way.
This was vividly presented in arresting video recordings shown this weekend at the annual meeting of the American Association for the Advancement of Science (AAAS) in San Diego, CA, February 18 – 22, 2010.
Dr. Gottfried Schlaug, of Beth Israel Deaconess Hospital and Harvard Medical School, Boston, and his team work with stroke victims. There are some 750 thousand such persons affected in the United States each year, a quarter of whom remain saddled with aphasia, the inability to form words. Stroke lesions on the left side of the brain can severely affect speech ability, though often not speech comprehension, which remains healthy.
Residing on the right side of the brain, meanwhile, is an area mirroring many of the properties and connections of our speech center on the left, but given over to – tra-la! – singing.
That patients unable to speak could still sing has been known in medical anecdotes for at least one hundred years. Some practitioners of stroke therapies in the 1970’s revived the practice for a time, but it failed to find enduring acceptance at that point.
“What we’re now doing,” said Dr Schlaug, “is going through the variety of tests and trials always required for a therapy to become clinically established.”
The method is called “Melodic Intonation Therapy,” and it seems to matter blessedly little how well the patients can sing – a rough intonation can suffice to help call the words forth.
While easy for caregivers and patients to learn about and begin, the therapy requires many dozens of “intensive sessions” to bring about positive changes. Final results of the trials are some time away, but the initial findings presented were impressively positive.
Good News for Bad Singers – and School Teachers
Sour Singers of the World: You have a bona fide, biological reason for your non-melodious tones!
Turns out, you also have good reason to persist in trying – or at least tapping your hands and feet – as best you can, because music experience enhances abilities also used for word comprehension and grammar.
These are the findings of two other neurobiologists working at the crossroads of speech and music, Dr. Aniruddh Patel of The Neurosciences Institute, San Diego, and Dr. Nina Kraus, of Northwestern University in Evanston, IL.
They are elucidating both interplay and counterpoint between these two human abilities. Singing is the most obvious, but far from sole, nexus between the brain cells that give us words and those that give us music.
Dr. Kraus showed that experience in music enhances skills also involved in learning to be listeners, readers and speakers. Dr. Patel presented complementary studies showing neural overlap in the grammatical processing of language and instrumental music. Importantly, some of the subtle brain functions enhanced in musicians are the same ones found to be defective in dyslexia and other learning disabilities.
As one might have predicted, musicians can pick out and follow a voice in a crowd better than non-musicians are able to.
“But even more amazingly” enthused Dr. Kraus, “their brains respond distinctly to the specific part of a baby’s cry already known to convey the most emotional content to a parent.”
She showed the sonic spectrum of a baby’s cry and the corresponding millisecond-timed peaks in neural firing from musicians’ and non-musicians’ brains. For much of the cry, the traces rise and fall in tandem – then there is a semi-second when the baby’s frequencies change and the musicians uniquely respond – before the two groups of listeners resume parallel brain waves.
Apparently music can help us not only to better understand others’ speech, but perhaps even how to better empathize with their feelings.
Speaking of empathy, about our sour-singing brethren…
It’s not their fault, of course – they just don’t seem to have much in the ol’ arcuate fasciculus department. That’s a band of nerve cells connecting major parts of our brains’ temporal (hearing) and frontal lobes, where so-called ‘executive functions’ occur, such as interpretation of sound and initiation of response.
Most of us have more of this tract on the left than the right side of the brain, though this is neatly reversed in professional singers. But those 10% or so of folks who just can’t “carry a tune” have very few of these fibers on the left side of the brain and basically none at all on the right.
This was also the work of Dr. Gottfried Schlaug, of the stroke therapy work above.
He didn’t say, but one suspects that he, Dr Patel and Dr. Kraus would all encourage non-singers to keep enjoying music as much as they paradoxically do. All three neuroscientists admitted a bit bashfully to being amateur musicians, along with having their children in music lessons.
This should come as music to the ears of arts educators everywhere – as well as to those suffering from learning disabilities that music processing in the brain promises to throw more light on.
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Leo Kretzner is a molecular biologist and science writer living in Claremont, CA.
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