and the Brain
Monday, November 18, 2002
Sex. Chocolate. Caffeine. Champagne. Cocaine.
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 Neurological 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
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 sexual
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.
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.
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.
brain even processes harmonic and dissonant music in different
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
favorite piece of music. Among the selections were Samuel
Barber's Adagio for Strings and Rachmaninoff's Piano Concerto
No. 3 in D minor.
of the subjects was played an excerpt from their favored 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
enough, chills tingled down the students spines as they heard
their favorite music selections. Their other vital signs spiked
upwards during 77 per cent of the scans. But the real discovery
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 fired in galaxies of
electro-chemical energy bursts, but away from areas where brain
neurons were relatively dormant.
the moments of musical euphoria, their 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
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
brain neurons, says Zatorre, are hard-wired for music -- from
cradle to grave. And the more we use 'em, the less we lose 'em.
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.
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 system.
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."
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
brain's chief task, Zatorre concludes, is to keep astonishing
itself. And music may do it best.
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."
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
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.
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.
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 per cent larger in musicians
trained since age eight.
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.
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."
to summarize what brain circuits are deployed when humans
process music, Zatorre momentarily jettisons his meticulous
scientific caution and flashes a grin.
from the neck up." he answers.
McKay is an Ottawa Citizen reporter. More music and photos for
this story, and previous stories in this series, can be seen at www.enchantedear.com.
details about the Zatorre/McGill studies can be found at www.zlab.mcgill.ca
Copyright 2002 The Ottawa Citizen.