Music is a window on the brain, scientists say. Few human activities exercise as many brain functions: Playing music demands motor skill, and listening to it stimulates both feelings and intellectual faculties. Scientists now use music to study sense perception, emotions, coordination, timing and the functions of each of the brain’s hemispheres.
The relationship between music and the brain is a fast-growing area of study. Last year, Frank Wilson, a Walnut Creek, Calif., neurologist, organized a conference on the subject, bringing together some 300 interested professionals.
Several books on the subject have been published in recent years, and a new psychology journal called Music Perception was founded in 1983.
Strokes and other brain disorders reveal much about brain functions, including music and language. In one recently reported case, a stroke knocked out only its victim’s ability to name fruits and vegetables, suggesting that categories of words are organized in the same area of the brain. Similarly, strokes have shown that key musical abilities are organized in the right half of the brain, which is associated with emotions and the integration of complex details into wholes.
Tedd Judd, a psychologist at the Pacific Medical Center in Seattle, tells of a composer who suffered a stroke on the right side of the brain and could still compose melodies. But he lost the ability to compose counterpoint, in which melodies are integrated according to complex rules.
Strokes on the right side sometimes erase the ability to sing, even though the memory of song lyrics may be intact. People afflicted that way may speak in a monotone because they can no longer put melody into their voices, says Elliott Ross, a neurologist at the University of Texas medical school.
But scientists now also realize that music isn’t totally a right-brain function. At the University of California at Los Angeles, John Mazziotta, a researcher, found that in most people listening to simple melodies, the right side of the brain was activated; but those who visualized what they heard as notes on a page mainly used the left side.
Music, long considered the language of emotions, is also an ideal stimulus for experiments on feelings. At Pennsylvania State University, a psychologist, Julian Thayer, plays different kinds of music from Bach to jazz while testing listeners for heart rates and other indicators of emotions. Among other things, his research suggests that just as a radio has separate controls for tone and volume, emotions involve independent levels of pleasantness and intensity.
Brain researchers have been trying for years to understand how the brain handles sensory input, and music is important to their study of sound perception. Scientists believe that some elements of music — like common pitch intervals — have been shaped to reflect the structure of the human auditory system. For example, most people, even in different cultures, perceive tones separated by an octave as closely related. This may result from the channeling of nerve impulses caused by such tones to the same nerve cell in the brain, says Diana Deutsch, a psychologist at the University of California at San Diego.
Tempo is another musical element that intrigues brain researchers. Most people can’t both walk and chew gum at different tempos because the brain can apparently monitor only one internal metronome at a time, says George P. Moore, a researcher at the University of Southern California.
Mr. Moore is also interested in the motor skills involved in playing a musical instrument, where muscle coordination and timing are crucial. Using sensors, including small needles inserted into musicians’ hands, he has learned that performers use unconscious tricks to improve their sound. For example, Mr. Moore found that when playing trills on a violin, some players lighten finger pressure. Then, to compensate for the pitch distortion the lighter pressure would cause, they adjust their hand positions. “Musicians don’t even know they do these things,” he says, which suggests that they subliminally refer to detailed brain “maps” of their instruments to create the desired sound.
Internal maps may guide listeners as well as players, which could explain the difficulty many people have learning to like unfamiliar music. There may even be music so alien that our brains aren’t equipped to make sense of it. “Some avant-garde composers who base their music on new arbitrary ystems are interesting,” says Roger Shepard, a Stanford University psychology professor. “But their music may never take hold with listeners because it doesn’t mesh effectively with the deep cognitive structures of the mind.”