This is your brain on music

Whether you are rocking out to Macklemore
& Ryan Lewis in your car or reading with Bach in your bedroom, music
has a special ability to pump us up or calm us down.

Scientists are still
trying to figure out what's going on in our brains when we listen to
music and how it produces such potent effects on the psyche.

"We're using music to
better understand brain function in general," said Daniel Levitin, a
prominent psychologist who studies the neuroscience of music at McGill
University in Montreal.

Three studies published
this month explore how the brain responds to music. The quest to dissect
exactly what chemical processes occur when we put our headphones on is
far from over, but scientists have come across some clues.

Health benefits of music

Listening to music feels good, but can that translate into physiological benefit? Levitin and colleagues published a meta-analysis of 400 studies in the journal Trends in Cognitive Sciences, suggesting the answer is yes.

In one study reviewed,
researchers studied patients who were about to undergo surgery.
Participants were randomly assigned to either listen to music or take
anti-anxiety drugs. Scientists tracked patient's ratings of their own
anxiety, as well as the levels of the stress hormone cortisol.

The results: The patients
who listened to music had less anxiety and lower cortisol than people
who took drugs. Levitin cautioned that this is only one study, and more
research needs to be done to confirm the results, but it points toward a
powerful medicinal use for music.

Making music sound 'better'

"The promise here is that
music is arguably less expensive than drugs, and it's easier on the
body and it doesn't have side effects," Levitin said.

Levitin and colleagues
also highlighted evidence that music is associated with immunoglobin A,
an antibody linked to immunity, as well as higher counts of cells that
fight germs and bacteria.

More: How music changes the brain

What music we like

So music is good for us, but how do we judge what music is pleasurable? A study published
in the journal Science suggests that patterns of brain activity can
indicate whether a person likes what he or she is hearing.

Valorie Salimpoor, a
researcher at the Rotman Research Institute in Toronto and former
Levitin student, led a study in which participants listened to 60
excerpts of music they had never heard before while in a functional
magnetic resonance imaging (fMRI) machine.

The 19 participants were
asked to indicate how much money they would spend on a given song when
listening to the excerpts, while also allowing researchers to analyze
patterns of brain activity through the fMRI. Such a
small number of participants is common in an fMRI study for reasons of
complexity and cost, although it suggests more research should be done.

The study authors
highlight in their results a brain area called the nucleus accumbens,
which is involved in forming expectations.

"There is actually a
network of activity that predicts whether or not you're going to buy
this music as you're listening to the music," Salimpoor said.

The more activity in the
nucleus accumbens, the more money people said they were willing to
spend on any particular song in the "auction" set-up that the
researchers designed.

"This was an indicator that some sort of reward-related expectations were met or surpassed," she said.

Another brain area
called the superior temporal gyrus is intimately involved in the
experience of music, and its connection to the nucleus accumbens is
important, she said. The genres of music that a person listens to over a
lifetime impact how the superior temporal gyrus is formed.

The superior temporal
gyrus alone doesn't predict whether a person likes a given piece of
music, but it's involved in storing templates from what you've heard
before. For instance, a person who has heard a lot of jazz before is
more likely to appreciate a given piece of jazz music than someone with a
lot less experience.

"The brain kind of works like a music recommendation system," Salimpoor said.

You can listen to the clips that the researchers used in the study here.

Levitin called the
findings "interesting," but views it as a refinement of what other
laboratories have found in the past. He and Vinod Menon at Stanford
University were the first to show the role of the nucleus accumbens in
music in 2005.

Beholding beauty: How it's been studied

Are we all hearing the same thing?

It seems intuitive that
different people, based on their personalities, preferences and personal
histories of listening to particular music, will have different
experiences when exposed to a particular piece of music. Their attention
to various details will vary and they might like different things about
it.

But Levitin and his collaborators showed in a European Journal of Neuroscience study that, from the perspective of the brain, there may be more similarities among music listeners than you think.

"Despite our
idiosyncrasies in listening, the brain experiences music in a very
consistent fashion across subjects," said Daniel Abrams, lead author and
postdoctoral researcher at Stanford University School of Medicine.

Seventeen participants
who had little or no music training took part in this study which, like
Salimpoor's, is small, but typical for an fMRI study. Participants
listened to four symphonies by composer William Boyce of the late
Baroque period, which the researchers chose because they reflect Western
music but were likely to be unfamiliar to subjects.

Among participants, the researchers found synchronization in several
key brain areas, and similar brain activity patterns in different
people who listen to the same music. This suggests that the participants
not only perceive the music the same way, but, despite whatever
personal differences they brought to the table, there's a level on which
they share a common experience.

Brain regions involved
in movement, attention, planning and memory consistently showed
activation when participants listened to music -- these are structures
that don't have to do with auditory processing itself. This means that
when we experience of music, a lot of other things are going on beyond
merely processing sound, Abrams said.

One resulting theory is
that these brain areas are involved in holding particular parts of a
song, such as the melody, in the mind while the rest of the piece of
music plays on, Abrams said.

The results also reflect the power of music to unite people, Levitin said.

"It's not our natural
tendency to thrust ourselves into a crowd of 20,000 people, but for a
Muse concert or a Radiohead concert we'll do it," Levitin said. "There's
this unifying force that comes from the music, and we don't get that
from other things."

Further research might
compare how individuals with healthy brains differ in their musical
listening compared to people with autism or other brain disorders,
Abrams said.

"The methods that we've used can be applied to understand how the brain tracks auditory information over time," Abrams said.

What the brain draws from: Art and neuroscience

What's next

The next frontier in the
neuroscience of music is to look more carefully at which chemicals in
the brain are involved in music listening and performing, Levitin said,
and in which parts of the brain are they active.

Any given neurochemical
can have different function depending on its area of the brain, he said.
For instance, dopamine helps increase attention in the frontal lobes,
but in the limbic system it is associated with pleasure.

By using music as a
window into the function of a healthy brain, researchers may gain
insights into a slew of neurological and psychiatric problems, he said.

"Knowing better how the
brain is organized, how it functions, what chemical messengers are
working and how they're working -- that will allow us to formulate
treatments for people with brain injury, or to combat diseases or
disorders or even psychiatric problems," Levitin said.

By Elizabeth Landau, CNN