|A SONG IN YOUR HEAD
Researchers at McGill University are using very fancy devices to learn how our brains react to music, writes Paul McKay.
|The Ottowa Citizen
Monday, November 28, 2002
Sex. Chocolate. Caffeine. Champagne. Cocaine.
If none of the above turn your cranial crank, it’s also likely that
Mozart or Alanis Morissette won’t send shivers down your spine.
And that your pulse rate should be checked by a doctor – because the
human survival instinct is hard-wired to the same brain circuits that
process intense pleasure.
A team of researchers at the Montreal Neuroological Institute, using
the world’s most advanced brain-mapping machines, have found that the
same neural clusters that process the seductive pleasures of sex,
chocolate and even hard drugs also fire up for music.
There is also persuasive evidence that the brain tends to prune these
neural circuits for maximum pleasure the way a gardener cuts
unproductive branches to make a rose bush bloom. Music, it seems,
may make the brain bloom best because it literally electrifies, at
lightning speed, a web of nerve paths in both hemispheres of our
cerebral cortex that connect the neural clusters processing musical
pitch, rhythm, harmony, melody, short-term memory, long-term memory,
and emotions. Now, for the first time, neuroscientists mapping
the musical mind at McGill University have confirmed that those music
circuits also comprise the inch-worm shaped clusters that process
exquisite pleasures, including illicit ones. But unlike other
addictions, it leaves no hangover, drug habits, clogged arteries, or
Sound too good to be true? If it is, billions of brain cells, a
$6-million MRI imaging machine, and a leading cognitive neuroscientist
are all wrong.
Robert Zatorre and his colleagues at McGill University have been
heading studies into the effects of music on the human brain for more
than two decades. Deep in the bowels of an old stone building on
the McGill campus, they scan human brains the way a geologist scans
mineral maps, except they are tracing, in real time, the topography of
human brains while circuits and clusters of neurons fire.
They and their international colleagues have used sophisticated PET and
MRI scanners to peer inside brains to detect where pitch, melody,
harmony and rhythm are processed. The answer, it turns out,
changes with the complexity and composition of the music. There
are distinct clusters of cortex that seem to be responsible for each
component of music, such as rhythm or harmony. Yet even the
simplest song heard or sung by a child sends showers of neural sparks
across both sides of the brain, linking each element of music to
respective cranial regions. Music also lights up the lobes where
memory is stored, the clusters where logic and speech are processed,
the brain stem where sounds relayed by the ear are filtered, and the
cerebral throne of emotion.
The brain even processes harmonic and dissonant music in different neural circuits.
For a landmark study published last year, Zatorre’s McGill team created
an experiment with remarkable results. Ten students, each with
advanced musical training, were asked to select a favourite piece of
music. Among the selections were Samuel Barber’s Adagio for
Strings and Rachmaninoff’s Piano Concerto No. 3 in D minor.
Each of the subject was played an excerpt from their favoured music
while they were scanned for brain neuron firing, cranial blood flow,
heart rate, EMG, respiration and skin temperature. All 10
subjects were also played an excerpt from another student’s selection,
a calibrated patch of ordinary noises, and a passage of silence.
Sure enough, chills tingled down the students’ spines as they heard
their favourite music selections. Their other vital signs spiked
upwards during 77 percent of the scans. But the real discover
came as the computer-linked scanner/cameras took split-second snapshots
through the multiple folds and mounds of grey matter. Blood
flowed to areas where neurons fire in galaxies of electro-chemical
energy bursts, but away from areas where brain neurons were relatively
During the moments of musical euphoria, cranial blood streamed to the
parts of the brain which previous, independent studies had isolated as
the places where sex, chocolate, champagne or cocaine can produce
ecstasy. In effect, 10 different cortex clusters burst into
neural fireworks, creating the familiar spine-tingling chills of
pleasure. Equally intriguing, the blood flowed away from brain
cells associated with depression and fear.
“We have shown that music recruits neural systems of reward and emotion
similar to those known to respond specifically to biologically-relevant
stimuli, such as food and sex, and those artificially activated by
drugs of abuse,” Zatorre concluded in his published paper. “This
is quite remarkable, because music is neither strictly necessary for
biological survival or reproduction, nor is it a pharmacological
Our brain neurons, says Zatorre, are hard-wired for music – from cradle
to grave. And the more we use ‘em, the less we lose ‘em.
“All normal children will spontaneously sing something like the Sesame
Street song,” he says in his McGill office while fielding phone calls
to book precious time on an MRI machine – which costs $400 per hour,
and primarily is used to scan patients. “That’s a very
sophisticated neurological feat. It means their brains recognize
the theme, and associate it with their favourite TV show. They
will try to sing it, on their own. They may not reproduce it very
accurately, but it is recognizable. No one can teach them this,
versus reading or math. Like blind children learning to walk,
they just do it when they are ready. It is wired into our nervous
“The vast majority of people with no musical training can sing a song,
and still recognize a tune when it has been altered by a different key,
instrument or rhythm. That seems to be innate, something our
brains are wired to do. And there is no known culture which does
not have some sort of music.”
The Zatorre study followed earlier McGill probes into how harmony and
dissonance affect the neural clusters known to process emotions; where
in the brain we select key features of voices; how people process
melodies; where musical pitch and rhythm are processed; and where the
mind’s eye imagines and perhaps invents music.
The brain’s chief task, Zatorre concludes, is to keep astonishing itself. And music may do it best.
“Music involves perception, memory, emotion, motor control, all the
learning aspects. It brings together a lot of different functions
in a very coherent way,” says Zatorre, who is also an accomplished
organist. “The brain wants patterns to assemble but it also
craves diversity, so a very important part of music is surprise.
And you can only be surprised if you anticipate – and don’t assume a
random series of notes.”
“The best music plays with that tension. If it goes too far in
lacking structure, it collapses into random sounds. Then your
nervous system loses interest; it just becomes noise. If you go
too far to the other extreme, where everything is completely
predictable, soon you’ll never play it again. The brain likes to
Zatorre and Isabel Peretz, a noted neuropsychologist at the University
of Montreal (see accompanying story) collaborate on complementary
studies, and assembled a newly published compilation of academic
reports called The Biological Foundations of Music. It summarizes
much of the past decade’s international research into the origins of
human music, particularly neurological evidence uncovered by brain
scanning technology and related experiments.
That text is augmented by continuing studies of the musical mind at
universities in Montreal, Toronto, Boston, California, and
Europe. Published in scientific journals and posted on university
and medical school Web sites, they reveal alluring evidence that:
- The brains of musicians, especially those who begin dedicated
practice before age 7, have larger neural clusters involving music
processing such as the neural region that directs a violinist’s hands –
sound perception and discrimination begins before birth, and neurons
begin firing before language skills develop in infants, aided by
parental cooing and lullabies.
- The brain selects the most efficient neural highways to process
music, closing those that create musical traffic jams and opening those
that make sounds flow faster. The more these circuits are used,
the more their musical range and capacity expands. Both
hemispheres of the brain share music processing functions and are
connected by a key neural bridge, the corpus callosum, which unites
specialized regions sending complex musical data at blinding
speeds. Recent studies indicate the 100 million-nerve conduit is
up to 15 percent larger in musicians trained since age eight.
- Music acts as a specialized fuel to fire millions of brain nerves
that otherwise remain dormant or undeveloped. As the brain burns
musical fuel, it creates chemicals that produce contentment and even
ecstasy. Recent studies of choir singers show elevated levels of
these after performances.
“The PET and MRI scans only became available in the last two decades,”
says Zatorre. “They have really revolutionized the whole field of
cognitive neuroscience – the study of the brain mechanisms that allow
us to perceive and think and act and reason and remember. They
allow us to probe the workings of the brain in normal people.
Before, we had to rely exclusively on those with brain damage.”
Asked to summarize what brain circuits are deployed when humans process
music, Zatorre momentarily jettisons his meticulous scientific caution
and flashes a grin.
“Everything from the neck up,” he answers.
Paul McKay is a Citizen reporter. More music and photos for this
story, and previous stories in this series, can be seen at
www.enchantedear.com. [Note: This link is now defunct].
More details about the Zatorre/McGill studies can be found at www.zlab.mcgill.ca