RESEARCH FOCUS 10-1 EVOLUTION OF LANGUAGE AND MUSIC

10-1 SOUND WAVES: STIMULUS FOR AUDITION

PHYSICAL PROPERTIES OF SOUND WAVES

PERCEPTION OF SOUND

PROPERTIES OF LANGUAGE AND MUSIC AS SOUNDS

10-2 FUNCTIONAL ANATOMY OF THE AUDITORY SYSTEM

STRUCTURE OF THE EAR

AUDITORY RECEPTORS

CLINICAL FOCUS 10-2 OTOACOUSTIC EMISSIONS

PATHWAYS TO THE AUDITORY CORTEX

AUDITORY CORTEX

RESEARCH FOCUS 10-3 SEEING WITH SOUND

10-3 NEURAL ACTIVITY AND HEARING

HEARING PITCH

DETECTING LOUDNESS

DETECTING LOCATION

DETECTING PATTERNS IN SOUND

10-4 ANATOMY OF LANGUAGE AND MUSIC

PROCESSING LANGUAGE

CLINICAL FOCUS 10-4 LEFT-HEMISPHERE DYSFUNCTION

PROCESSING MUSIC

CLINICAL FOCUS 10-5 CEREBRAL ANEURYSMS

RESEARCH FOCUS 10-6 THE BRAIN’S MUSIC SYSTEM

10-5 AUDITORY COMMUNICATION IN NONHUMAN SPECIES

BIRDSONG

ECHOLOCATION IN BATS

Evolution of Language and Music

The finding that modern humans (Homo sapiens) made music early on implies that music has been important in our evolution. Behavioral scientists have shown that music plays as central a role in our social and emotional lives as language does.

Thomas Geissmann (2001) noted that among most of the 26 species of singing primates, males and females sing duets. All singing primates are monogamous, suggesting that singing may somehow relate to sexual behaviors. Music may also play a role in primates’ parenting behaviors.

The human brain is specialized for analyzing certain aspects of music in the right temporal lobe, which complements the left temporal lobe specialization for analyzing aspects of speech. Did music and language evolve simultaneously in our species? Possibly.

Neanderthals (Homo neanderthalensis) have long fascinated researchers. The species originated about 300,000 years ago and disappeared about 30,000 years ago. During some of that time they coexisted in Europe and the Middle East with Homo sapiens, whom they resembled in many ways because they shared a common ancestor. In some locales, the two species may have shared resources and tools.

Researchers long hypothesized that Neanderthal culture was significantly less developed than that of early modern humans. Yet Neanderthals had a brain as large as or larger than that of Homo sapiens, with whom they appear to have shared many cultural similarities. Neanderthals buried their dead with artifacts, which implies that they held spiritual beliefs, but we have no conclusive evidence that they made visual art. In contrast, Homo sapiens began painting on cave walls some 30,000 years ago, near the end of the Neanderthal era.

Anatomically, some skeletal analyses of the larynx suggest that Neanderthals’ articulated language ability was less well developed than their Homo sapiens contemporaries’. What about music? It appears that Neanderthals did make music.

Shown in the accompanying photo is the bone flute found in 1995 by Ivan Turk, a paleontologist at the Slovenian Academy of Sciences in Ljubljana. Turk was excavating a cave in northern Slovenia used by Neanderthals long ago as a hunting camp. Buried in the cave among a cache of stone tools was the leg bone of a young bear that looked as if it had been fashioned into a flute.

The bone has holes aligned along one side that could not have been made by gnawing animals. Rather, the holes’ spacing resembles positions found on a modern flute. But the bone flute is at least 43,000 years old—perhaps as old as 82,000 years. All the evidence suggests that Neanderthals, not modern humans, made the instrument.

Bob Fink, a musicologist, analyzed the flute’s musical qualities. He found that an eight-note scale similar to a do-re-mi scale could be played on the flute, but compared with the scale most familiar in European music, one note was slightly off. That blue note, a staple of jazz, is standard in musical scales throughout Africa and India today.

The similarity between Neanderthal and contemporary musical scales encourages us to speculate about the brain that conceived this ancient flute. Like modern humans, Neanderthals probably had complementary hemispheric specialization for language and music. This may have contributed to the two species cohabitating and to interbreeding that led to 1 to 4 percent of alleles being of Neanderthal origin in humans whose lineages, in the last 30,000 years, come from outside of Africa.

Language is independent of making or perceiving sounds, as sign language demonstrates. In this chapter, however, language refers to speech.