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This is Your Brain in Tune
Beethoven and Jimi Hendrix, Mozart and Nat King Cole: All had the rare and mysterious musical ability called perfect pitch. Neuroscientist David Ross is investigating why their brains allowed them to recognize and reproduce tones unerringly, and why the rest of us can’t.
September/October 2003
by Bruce Fellman
Bruce Fellman, a banjo picker unencumbered by perfect pitch, is the managing editor of the Yale Alumni Magazine.
Samantha Foggle had just turned three in June of 2000 when her family moved from Massachusetts to Connecticut, and the appliances started to sing.
In the course of the move the family had acquired an upright piano, and in a spare moment between unpacking boxes, Samantha’s mother, Lili, plunked out a melody. “I don’t really know how to play—we’re not a musical family—but I could manage ‘Do-Re-Mi,’ from The Sound of Music,” Lili says. Samantha was delighted. “A few days later, I was in the kitchen heating food in the microwave, and it was humming,” recalls Lili. “Samantha said, ‘It’s an F, Mommy!’ I ran over to the piano and played that note. Sure enough, it was an F.”
For other children and their amazed parents, it’s the hair dryer singing a B-flat, or the can opener running at G. An uncanny talent for naming the pitch of a household appliance is often the first sign that a child possesses one of the rarest and strangest of musical gifts: the ability to identify any tone or to reproduce it without needing to compare it with another tone for reference.
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“I’d love to be able to look at a score and hear what it’ll sound like.” |
Many of the greatest composers—Beethoven, Bach, Chopin, Handel, Mozart, and Bartok, to name several—are thought to have had perfect pitch, which scientists call absolute pitch (AP). The same goes for Nat King Cole, Stevie Wonder, Barbra Streisand, Yo-Yo Ma, Brian Wilson, and Jimi Hendrix. “You don’t need AP to survive in society, or the world of music,” says Thomas Duffy, deputy dean of the School of Music. “But I’d love to be able to look at a score and, without having to sit down at the piano, hear what it’ll sound like.” Ask someone with AP to play or sing from memory a passage from a Brandenberg concerto or a riff from “Purple Haze,” and the job is done precisely on key, with no effort. Ask the person to sing it a minor third lower, and the response is instant and just as flawless.
To the ordinary listener, this seems like, well, witchcraft. (Frank Sinatra had AP.) Most of us have relative pitch, the ability to hear differences between musical tones. A few trained musicians have a heightened ability to recognize one particular pitch, or pitches played on certain instruments. But only one in ten thousand has genuine AP as German physiologist A. Bachem observed it in his test subjects in 1937: “The[ir] absence of reflection and humming excludes the possibility of a comparison of the test tone with any standard. This grade of absolute pitch may be called infallible and universal absolute pitch.”
Scientists have been hard pressed to come up with an adequate explanation for the phenomenon. But the advent of new neurological imaging tools is beginning to change the field. David Ross ’99, a budding neurobiologist in the fifth year of Yale’s MD/PhD program, is one of the researchers now using these tools to watch the AP brain at work. “People who have AP live in a different perceptual universe from the rest of us,” says Ross, who is a dedicated amateur singer but does not have perfect pitch. “Figuring out how they do this will give us a window into the larger mystery of music perception.”
When Ross was an undergraduate, he met someone with AP, and the experience left a lasting, if not entirely positive, impression. He auditioned for the a cappella group Redhot and Blue, and the musical director asked him to sing a C. “I had no idea what a C was,” says Ross. “Notes had no identity for me, so she was asking me to hear things that just didn’t make sense.” (He got in anyway.) Exasperated but intrigued, he started trying to find out why she could hear what he couldn’t.
Psychologists have done some intriguing studies of pitch perception at different ages and in different cultures. Jenny Saffran of the University of Wisconsin and Diana Deutsch of the University of California at San Diego, for instance, have suggested that infants may have better pitch perception than adults, but lose it unless they use it for learning tonal languages such as Vietnamese. David Huron, an Ohio State University musicologist, has found that people respond automatically, with nurturing and protectiveness, to the high-pitched cooing and gurgling of infants.
Neuroanatomically, however, there wasn’t much to go on. Scientists understand, in fine detail, how the human visual system works, but there are many uncertainties about the biology of hearing.
In 1851, Alfonso Corti, an Italian researcher working in Germany, discovered the basic anatomy of the inner ear. A decade later, the eminent German physicist Hermann von Helmholtz suggested that sound waves in the air might trigger specific patterns of vibrations in the snail-shaped organ called the cochlea. In the 1930s and later, University of Budapest scientist Georg von Bekesy confirmed von Helmholtz’s conjectures in a series of papers showing how sound waves of certain frequencies activated only specific places in the cochlea’s basilar membrane. This “place code” then traveled along the auditory nerve to the brain stem for processing, and finally to the auditory cortex, where it could be discerned as a certain pitch.
But over the years, scientists found that place coding, by itself, couldn’t account for even ordinary skill at pitch discrimination. They realized that information was also being conveyed by a second type of code, one based on the timing patterns of the electrical impulses that result when inner-ear nerve cells are stimulated by sounds. Temporal encoding is thought to be critical in processing pitch, but it is poorly understood.
Then came magnetic resonance imaging (MRI). It was during the 1990s that neurobiologists began learning how to use MRI devices, originally developed to detect damage to the body’s soft tissues, for mapping the mind. MRI uses magnetic energy to induce different chemical elements in the brain to emit distinctive radio signals. The signals are then rendered in different colors that produce two-dimensional snapshots of brain activity. A recent innovation, called functional MRI (fMRI), is to MRI what the moving picture was to the camera: It films blood flow in the brain over time, revealing sequence and process as the brain works on a task.
As an undergraduate, Ross went to John Gore, then professor of diagnostic radiology and applied physics, to explore the possibility that fMRI could be used to study AP. Gore saw it as an opportunity to help scientists understand how the auditory cortex is integrated and how humans recognize sounds. (He has since moved to Vanderbilt University but continues to supervise Ross’s doctoral research.) For his senior thesis and his subsequent graduate studies, Ross found six people with AP and compared their performance on a series of tasks with that of 13 non-AP musicians.
Ross puts his subjects through a complicated battery of tests. He starts with note naming. “Musicians with AP are incredibly fast at this and can often name a note before we’re done playing it,” he says. “By contrast, great musicians who only have relative pitch skills, however highly refined, just can’t do this.”
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After seven interference notes, even professional musicians have completely lost the first tone.
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Next, he plays a series of tones and asks the subject to reproduce them on a tone generator. At its simplest level, this is a task almost anyone can do. But then things get increasingly tricky. After he plays a note, Ross waits for up to 16 seconds before he asks the subject to reproduce it. Next, he’ll play a string of several different tones and ask the subject to reproduce the first one. After seven interference notes, most people, including professional musicians, have completely lost the first tone. “You can really see them sweat,” says Ross. But for six-year-old Samantha Foggle and other AP subjects, the tests are almost ludicrously easy.
The difference is obvious on the fMRI images. “The six AP musicians were demographically as different as you can imagine—in the group was everyone from a 19-year-old black saxophone player to a 50-year-old Spanish cellist,” says Ross. “And yet their brain activation patterns looked absolutely identical.” In the AP group, three distinct regions of the brain glowed strongly and consistently as the subjects named and reproduced different musical tones. No one in the non-AP group showed this pattern. In fact, there was no common pattern at all among the non-AP subjects. (Ross’s results have been presented at scientific meetings and will be published later this year in the journal Magnetic Resonance Imaging.)
Robert J. Zatorre, director of the auditory processing laboratory at the Montreal Neurological Institute, has published several brain imaging studies involving AP. In a review paper published in July in the journal Nature Neuroscience, Zatorre also found “interesting differences” in brain activity and anatomy between musicians with and without AP, similar to those Ross found. But—while there’s very little hard evidence at present—both Zatorre and Ross believe that their findings are simply cerebral reflections of more basic differences in processes that are taking place in the most primitive part of the brain, the brain stem. It is here, notes Ross, that the information from the inner ear passes through various detection and analysis centers, and it is probably here, he believes, that a fundamental anatomical difference in wiring exists. Ross’s hypothesis is that people with AP possess an additional neural connection that enables them to tap directly into the timing patterns passing along the auditory nerve. Each individual pattern, encoded by the brain, then serves as an absolute representation of each individual pitch. When stored in the brain’s long-term memory vaults, the codes become a registry that lets the AP-gifted identify tones or reproduce them as easily as someone looking up a number in a phone book.
Ross is particularly interested in understanding the wiring of this process. “What we’re seeing in the fMRI scans is only the tip of the iceberg,” he says. “We’re hoping to develop ways to actually see the brainstem at work and confirm our model.”
In Ross’s view, AP can’t be learned; it’s a genetic fluke. He has even found AP in a non-musician, Subject RM, whose only musical training was middle-school band. RM utterly flunked the note-naming test. But he sailed through the most complicated tone-reproduction exercises.
These results have made Ross unpopular in some quarters. The Perfect Pitch Ear Training SuperCourse and similar enterprises like to promulgate the notion that AP is a skill anyone can acquire, given the proper training and instructional tapes (operators are standing by). Ross has tested a subject who claimed to have taught himself to have AP; the subject failed. Musical training, Ross says, doesn’t foster AP so much as reveal it.
Besides, says Ross, this debate misses the central point he’s trying to make. “True AP is not the ability to name notes,” he says. “True AP is a fundamentally different way of encoding pitch.”
Even musicians say that AP, helpful as it is, is far from essential for music or musicianship. “With perfect pitch you’re able to recognize a tone as, say, A, but there’s a range within that A,” says Joanna Maurer, the violinist with AP who is a member of the American Chamber Players. In actual musical performance, especially with a group, she explains, “Perfect pitch does not mean perfect intonation. It’s the right combination within a note’s range that leads to good intonation.”
“AP enables you to have a more discerning ear,” adds Miles Hoffman ’73, violist and artistic director of the American Chamber Players, who does not have the ability. “It gives you more information about what you’re hearing. But it isn’t a guarantee of taste, intelligence, or musicality. You still need to practice.”  |
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