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January 11, 2009

CMU, UPMC RESEARCHERS LOOK AT HOW MELODIES AFFECT THE BRAIN

Nearly 20 years ago, the so-called Mozart Effect made a big splash.

The assertion that listening to Mozart’s music made you smarter — and would be good for your babies, too — was and is attractive to many people. Not surprisingly, claims for the Mozart Effect also provoked contrary opinions.

Trying to understand how the brain works — with or without music — has been like this for millennia. Philosophers speculated, physicians and researchers observed and tested, but generalizations never explained enough. It’s still true.

In recent decades, however, advanced medical-imaging technologies have provided a fundamentally new window into mental activity. Researchers can see the activity of neurons, the basic cells of the brain. These ultra hi-tech devices have fueled many lines of inquiry, including the study of music cognition — how neurons react to the stimulus of music.

Carnegie Mellon University’s Richard Randall, who teaches music theory, has long been fascinated by how we perceive music. He’s teaming up with UPMC’s Dr. Anto Bagic to be among the first to use one of these technologies — a magneto-encephalogram, called MEG — to study music cognition.

With MEG, Randall says, "we can see what’s happening almost in real time as the brain is processing a musical stimulus.

“That’s what got me excited,” he says. “It’s how we experience music, not in a snapshot format, but in a very fast-frame movie format.” While Randall’s research with Bagic will look at specific musical issues, he says it will also “illuminate fundamental cognitive issues, such as comprehension, memory, attention and performance.”

MEG technology

Although the first MEG recording was made in 1969, practical MEGs took more than a decade to develop. The latest generation of systems came online in the 1990s, Bagic says. UPMC acquired the one he’s using in 2005.

Bagic is chief of the epilepsy division and director of the Center for Advanced Brain Magnetic Source Imaging & MEG Program atUPMC. The main clinical use of MEG is for epilepsy, to find ground zero in the brain of the unwanted electrical discharges.

MEGs measure the miniscule magnetic fields generated by the brain.

“As long as there is brain activity there is an exchange of charged electrical particles, changing electric fields that generate corresponding magnetic fields,” Bagic says.

Detecting those magnetic fields is doubly challenging. A super sensitive device is needed because the brain’s magnetic field is very weak, Bagic says. The MEG sensors are called squids — super conducting quantum interference devices. Squids are submerged in liquid helium to bring their temperature down to minus-451 degrees Fahrenheit.

At that temperature, the sensors have no resistance and can detect signals that would be lost in the normal resistance of metal. The sensors are shielded so that patients and study subjects don’t feel the cold.

In addition, Bagic says, because “the magnetic field of our mother earth is 100 million times stronger than the magnetic fields operating in the brain, we have to put the machine in a specially designed magnetically shielded room.”

Research plans

One of the studies Randall plans to make with Bagic will center on the brain’s melodic expectations.

“We know where a melody is going to go even with something we haven’t heard before,” Randall says. “It’s an intuition we all have.”
Randall offers a story to illustrate musical expectation: Composer Johann Sebastian Bach had already gone to bed one night when one of his kids went to the keyboard and played only the first seven notes of an eight-note octave scale. Bach was so irked he had to get up and play the missing note.

Randall’s music-theory background comes to the fore when he says that syntax violations in music, such as the missing last note of the scale in the Bach household, will produce the same kind of neurological response as a syntax violation in language.

“A number of neurological studies in the last 10 years (with other measurement devices) have shown very clearly that music and language are processed in similar ways,” he says.

Solid research shows that people who have lost the ability to speak somehow can retain the ability to sing, he says. Oliver Sacks, in his 2007 book “Musicophilia,” even reports the case of a man who lost his ability to speak but regained some verbal ability through his ability to sing.

There are so many areas of interest to explore that Randall and Bagic could make a list of possible studies that would take decades to investigate.

“We’re starting to understand our mirror neurons,” Randall says as an example. When you see someone jumping, the visual cortex is activated, but the motor cortex is activated sympathetically. When you listen to a march, your motor cortex will be activated, too."
But it’s all in the brain. Don’t expect that listening to exercise music will take off any pounds.