Speaking in Tones Music and language are partners in the brain. Our sense of song helps us learn to talk, read and even make friends By Diana Deutsch 36 SCIENTIFIC AMERICAN MIND July/August 2010 © 2010 Scientific American ne afternoon in the summer of opera resembling sung ordinary speech), the cries 1995, a curious incident occurred. of street vendors and some rap music. I was fi ne-tuning my spoken com- And yet for decades the experience of musicians mentary on a CD I was preparing and the casual observer has clashed with scientifi c ) about music and the brain. To de- opinion, which has held that separate areas of the music tect glitches in the recording, I was looping phrases brain govern speech and music. Psychologists, lin- O so that I could hear them over and over. At one point, guists and neuroscientists have recently changed their sheet ( when I was alone in the room, I put one of the phras- tune, however, as sophisticated neuroimaging tech- es, “sometimes behave so strangely,” on a loop, be- niques have helped amass evidence that the brain ar- gan working on something else and forgot about it. eas governing music and language overlap. The latest iStockphoto Suddenly it seemed to me that a strange woman was data show that the two are in fact so intertwined that singing! After glancing around and fi nding nobody an awareness of music is critical to a baby’s language there, I realized that I was hearing my own voice re- development and even helps to cement the bond be- petitively producing this phrase—but now, instead tween infant and mother. As children grow older, mu- of hearing speech, I perceived a melody spilling out sical training may foster their communication skills ); MARCELA); BARSSE of the loudspeaker. My speech had morphed into and even their reading abilities, some studies suggest. song by the simple process of repetition. What is more, the neurological ties between music and mouth ( This striking perceptual transformation, which language go both ways: a person’s native tongue infl u- I later found occurs for most people, shows that the ences the way he or she perceives music. The same suc- boundary between speech and song can be very cession of notes may sound different depending on the fragile. Composers have taken account of the strong language the listener learned growing up, and speak- age Fotostock age connections between music and speech, for exam- ers of tonal languages such as Mandarin are much ple, incorporating spoken words and phrases into more likely than Westerners to have perfect pitch. their compositions. In addition, numerous vocaliza- tions seem to fall near the boundary between speech Word Symphonies and song, including religious chants and incanta- Musicians and philosophers have long argued PIOTRPOWIETRZYNSKI tions, oratory, opera recitative (a style of delivery in that speech and melody are interconnected. Russian www.ScientificAmerican.com/Mind SCIENTIFIC AMERICAN MIND 37 © 2010 Scientific American Certain vocalizations composer Modest Mussorgsky believed that music speech sounds. This attractive dichotomy became fall close to the border and talk were in essence so similar that a composer so popular that it effectively shut out for decades between speech and any thought that language and music might be neu- song. These include could reproduce a conversation. He wrote to his opera recitative, the friend Rimsky-Korsakov: “Whatever speech I hear, rologically—and functionally—intertwined. shouts of street ven- no matter who is speaking … my brain immediate- But then, by the late 1990s, a generation of young dors and the chanting ly sets to working out a musical exposition of this researchers who did not have a stake in the separation of rap musicians. speech.” Indeed, when you listen to some of his pi- of speech and song began questioning the idea. They ano and orchestral works, you may suddenly find brought to light existing data indicating that some as- that you are “hearing” the Russian language. pects of music engage the left hemisphere more than Despite such informal evidence of the ties be- the right. In addition, pioneering new experiments, tween speech and music, researchers—bolstered in many of which were conducted with emerging tech- part by patients whose brain damage affected their nology such as functional magnetic resonance im- speech but spared their musical ability—began es- aging, showed that music and speech are not as neu- pousing the opposite view around the middle of the rologically separate as researchers had supposed. 20th century. The brain divides into two hemi- One line of investigation demonstrated that the spheres, and these experts hypothesized that its perception and appreciation of music could impinge functions were just as neatly organized, with lan- on brain regions classically regarded as language guage residing on the left side and music on the processors. In a 2002 study neuroscientist Stefan ) right. Their theory was that the neural signal for di- Koelsch, then at the Max Planck Institute for Human alogue bypassed the usual pathways for sound pro- Cognitive and Brain Sciences in Leipzig, Germany, rapper ( IS cessing and instead was analyzed in an independent and his colleagues presented participants with se- B R O “module” in the brain’s left hemisphere. That mod- quences of chords while using functional MRI to C / ule supposedly excluded nonverbal sounds such as monitor their brains. They found that this task RT PO music. Similarly, the theory went, music was pro- prompted activity on both sides of the brain but most S W cessed in a right-hemisphere module that excluded notably in two regions in the left hemisphere, Broca’s NE and Wernicke’s areas [see illustration on opposite ); page], that are vital for language processing and that vendor FAST FACTS many researchers had assumed were solely dedicated ( ES Singing in the Brain to this function. Other more recent studies have re- G IMA vealed that speaking activates many of the same Y The brain circuits that interpret music overlap with those brain regions as analogous tasks that require singing. ETT 1>> that process speech. These and dozens of findings by other experimenters ); G have established that the neural networks dedicated The musical qualities of speech are critical in early lan- to speech and song significantly overlap. guage development and in cementing the bond between This overlap makes sense, because language and singers opera 2>> ( infant and mother. music have a lot in common. They are both governed ES G by a grammar, in which basic elements are orga- IMA A person’s native language may affect the way he or she nized hierarchically into sequences according to es- Y >> hears a set of musical notes. tablished rules. In language, words combine to form ETT 3 P/G phrases, which join to form larger phrases, which in AF 38 SCIENTIFIC AMERICAN MIND July/August 2010 © 2010 Scientific American Language and music are both governed by a grammar: basic elements organized hierarchically into sequences. turn combine to make sentences. Similarly, in mu- sic, notes combine to form phrases, which connect Broca’s area to form larger phrases, and so on. Thus, to under- stand either language or music, listeners must infer the structure of the passages that they hear, using rules they have assimilated through experience. In addition, speech has a natural melody called prosody. Prosody encompasses overall pitch level and pitch range, pitch contour (the pattern of rises and falls in pitch), loudness variation, rhythm and tempo. Prosodic characteristics often reflect the speaker’s emotional state. When people are happy or excited, they frequently speak more rapidly, at higher pitches and in wider pitch ranges; when people are sad, they tend to talk more slowly, in a lower voice and with less pitch variation. Prosody also helps us to understand Wernicke’s area the flow and meaning of speech. Boundaries between phrases are generally marked by pauses, and the end- ings of phrases tend to be distinguished by lower pitches and slower speech. Moreover, important words are often spoken at higher pitches. Interesting- listen to the voices with which they had become fa- The appreciation of ly, some pitch and timing characteristics of spoken miliar before birth. Then, in 1996, psychologists music requires many of the same brain language also occur in music, which indicates that Melanie J. Spence and Mark S. Freeman of the Uni- regions that are in- overlapping neural circuitries may be involved. versity of Texas at Dallas reported carrying out a volved in the process- similar experiment in which they used a low-pass fil- ing of language. These Meaningful Melodies ter to muffle recorded female voices so that they multipurpose regions include Broca’s (pur- At birth, babies are already familiar with the sounded as they would in the womb. The newborn ple) and Wernicke’s melody of their mother’s speech. Audio recordings babies preferred their mothers’ filtered voices over (green) areas. taken from inside the womb at the beginning of la- those of other women, again indicating that they had bor reveal that speech sounds produced by the become familiar with the melodies of their mothers’ mother can be loudly heard. The phrases reaching utterances in the womb. the baby have been filtered through the mother’s tis- In addition to forging a nascent connection be- sues, however, so that the crisp, high frequencies— tween mother and child, early exposure to musical which carry much of the information important for speech sounds may begin the process of learning to identifying the meanings of words—are muted, talk. In one 1993 study, for example, two-day-old whereas the musical characteristics of speech—its babies preferred to listen to recordings of speech in pitch contours, loudness variations, tempo and their native language to those in a foreign tongue.