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Dr. Daniel Levitin |
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Music has a profound and timeless power to move us. Dr. Daniel Levitin, professor of psychology
and neuroscience at McGill University and author of This Is Your Brain on Music: The Science of a Human Obsession, recently visited NIH to share his research findings.
“For the last 15 years, I’ve looked at why we have goosebumps when we listen to music,” he told the SRO crowd in the Neuroscience Center at Executive Plaza. His lecture was part of the NIMH Director’s Innovation Speaker Series.
A former studio musician and independent producer
who has worked with Eric Clapton, the Grateful Dead and Stevie Wonder, Levitin said he’d always felt the magic. After dropping out of MIT, he started his own production company, racking up 16 gold and platinum albums.
The turning point came during a session with Carlos Santana, the Grammy Award-winning guitarist. “I asked myself, why was I getting goosebumps? What transcended that moment?”
Levitin sold his business,
phasing out of the studio and into Stanford
University where he studied psychology and cognitive science. He now heads the Laboratory for Music Perception, Cognition and Expertise at McGill, researching the science of musical sound as well as “more speculative issues, where music meets evolution and genetics.”
Levitin noted evidence for music’s beneficial effects on health, yet “before 2003,” he said, “there were relatively few scientifically controlled
studies addressing the underlying mechanisms.
Singing releases endorphins, but why?”
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Levitin (l) worked closely with Charles Tolbert, AV specialist, to play sample audio clips used in his experiments. |
Singing also increases oxytocin, the “bonding” hormone. Immunoglobulin A, a critical antibody, goes up when we listen to music. Serotonin and key neurotransmitters increase after 4 weeks of music therapy and then decrease after it’s discontinued. And, Levitin noted, even among those with Alzheimer’s, music may be “the last thing to go. Even if they don’t know their own spouse, they can sing the songs of their youth. Something evolutionary is going on here.”
Understanding the mechanisms of how music creates pleasure “would provide part of a fully formed scientific theory.” Playing sound clips, Levitin invited the audience to listen. Some highlights:
Our recognition of sounds is so extraordinary that we can identify them within 500 milliseconds.
As soon as Levitin played a half-second clip of the Beatles’ “Eleanor Rigby,” the audience
got it.
By age 5, any child can say what chord is out of sequence according to his or her cultural context.
“As [Noam] Chomsky says, we’re all linguistic
experts,” Levitin said. “We’re all musical
experts.”
The brain fills in missing information to hear a continuous stream of sound despite interruptions.
“The brain knows that in a natural environment,
often sound is occluded, but we can cope with that.”
The brain groups sounds by similarity. “If there is a change in timbre [tonal sound], the brain binds together like elements.”
The brain does “template match”; for example,
if a symphony is performed with mandolins
instead of an orchestra, we recognize it. Yet “this is such a difficult problem that there’s no computer in the world that can do it.”
The brain can also recognize well-known music played with a power saw used on different lengths of wood. “We are able to make subtle discriminations about the music we know.”
While there are elaborate maps of how the visual
cortex processes color, edge, movement and the like, there are few such schematics of the auditory pathway. Music, said Levitin, goes to the auditory cortex, fans out to the computational
units, hits areas where melody, rhythm and timbre are processed, then comes back together within 30 milliseconds.
We remember a piece better if we see it performed.
“From an evolutionary perspective, and in most preliterate societies, music and dance always co-occur; the brain evolved watching
music and listening to it at the same time.” When we hear music, our motor cortex is firing; to keep still, we have to suppress it.
Music activates the same brain centers as chocolate,
opium and orgasm. Levitin believes “there is a reward system in place for learning music.”
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Dr. Teresa Levitin of NIDA (l) introduced McGill’s Dr. Daniel Levitin. They are cousins. |
The brain is also “a structure detector”; it can spot odd chords, “violations of harmonic expectancy,”
or familiar segments scrambled in random
order: “A tiny spot in the prefrontal cortex detects structure in anything and has a connection
to the brain’s emotional centers.”
In specific populations with neurogenetic impairments, Levitin compared those with Williams
syndrome (who are highly social and highly
musical) with people with autism spectrum disorders (who are non-social and not very musical). What do they hear when they hear music? With Williams, there was “diffuse activation,”
making Levitin wonder if there may be a gene cluster that influences both musicality and “outgoingness.”
Audience question: Why is some music pleasurable
and other music “just noise?”
“Humans differ,” Levitin said. “Taste hasn’t been worked out.” What is understood is that “we all become fixed in musical taste by around age 14 or 15.” Until then, the brain has been making new connections like crazy, but after age 15 “the brain prunes out unneeded connections.”
After that, “trying to like a different type of music is like trying to learn a new language.”
You get Beethoven, your teen gets Green Day, but everybody gets goosebumps.