[Dixielandjazz] Music & Darwin

[Stephen Barbone]

NOT OKOM, But a discussion of the "brain" and "music appreciation".
Interesting if you are curious. If not, DELETE NOW.

Cheers,
Steve Barbone




September 16, 2003 - New York Times

We Got Rhythm; the Mystery Is How and Why

By NICHOLAS WADE

In lovers' songs, military marches, weddings and funerals — every
occasion where a degree of emotion needs to be evoked — music is an
indispensable ingredient.

Yet the ability to enjoy music has long puzzled biologists because it
does nothing evident to help survival. Why, therefore, should evolution
have built into
the human brain this soul-stirring source of pleasure? Man's faculties
for enjoying and producing music, Darwin wrote, "must be ranked among
the most
mysterious with which he is endowed."

Music is still a mystery, a tangle of culture and built-in skills that
researchers are trying to tease apart. No one really knows why music is
found in all
cultures, why most known systems of music are based on the octave, why
some people have absolute pitch and whether the brain handles music with

special neural circuits or with ones developed for other purposes.
Recent research, however, has produced a number of theories about the
brain and
music.

It could be that the brain perceives music with the same circuits it
uses to hear and analyze human speech, and that it thrills to its
cadences with centers
designed to mediate other kinds of pleasure. Dr. Anne Blood and Dr.
Robert J. Zatorre, of the Montreal Neurological Institute, recently took
PET scans
of musicians' brains while they listened to self-selected pieces of
music that gave them "chills" of euphoria. The works included
Rachmaninoff's Piano
Concerto No. 3 and Barber's Adagio for Strings. The music, the
researchers reported, activated similar neural systems of reward and
emotion as those
stimulated by food, sex and addictive drugs.

If music depends on neural circuits developed for other reasons, then it
is just a happy accident, regardless of evolution, that people enjoy it.
This is the
position taken by Dr. Steven Pinker, a psychologist at Harvard
University. Music, he writes in his 1997 book "How the Mind Works," is
"auditory
cheesecake" — it just happens to tickle several important parts of the
brain in a highly pleasurable way, as cheesecake tickles the palate.
These include the
language ability (with which music overlaps in several ways); the
auditory cortex; the system that responds to the emotional signals in a
human voice
crying or cooing; and the motor control system that injects rhythm into
the muscles when walking or dancing.

That music can activate all these powerful systems at once is the reason
it packs such a mental oomph, in Dr. Pinker's analysis. But since each
of these
systems evolved for independent reasons, music itself is no more an
evolutionary adaptation than is the ability to like dessert, which
arises from intense
stimulation of the taste buds responsive to sweet and fatty substances.

But other evolutionary psychologists believe the faculty of enjoying
music is no accident. Darwin suggested that human ancestors, before
acquiring the
power of speech, "endeavored to charm each other with musical notes and
rhythm." It is because of music's origin in courtship, Darwin believed,
that it is
"firmly associated with some of the strongest passions an animal is
capable of feeling."

In his theory of sexual selection, Darwin proposed that traits found
attractive in courtship would enable their owners to get more genes into
the next
generation. The upshot would be the emergence of adornments that had no
immediately obvious survival value in themselves, like the peacock's
tail or the
troubadour's ballads.

Darwin's ideas about music have been extended by Dr. Geoffrey Miller, an
evolutionary psychologist at the University of New Mexico. Dr. Miller
notes
their potency in pointing to the opportunities open to popular musicians
for transmitting their genes to the next generation. The rock guitarist
Jimi
Hendrix, for instance, had "sexual liaisons with hundreds of groupies,
maintained parallel long-term relationships with at least two women, and
fathered at
least three children in the United States, Germany, and Sweden. Under
ancestral conditions before birth control, he would have fathered many
more," Dr.
Miller writes.

Why on earth would nubile young women choose a rock star as a possible
father of their children instead of more literary and reflective
professionals
such as, say, journalists? Dr. Miller sees music as an excellent
indicator of fitness in the Darwinian struggle for survival. Since music
draws on so many
of the brain's faculties, it vouches for the health of the organ as a
whole. And since music in ancient cultures seems often to have been
linked with
dancing, a good fitness indicator for the rest of the body, anyone who
could sing and dance well was advertising the general excellence of
their mental
and physical genes to a potential mate.

"Music evolved and continues to function as a courtship display, mostly
broadcast by young males to attract females," Dr. Miller writes in "The
Origins
of Music," a collection of essays by him and others.

But other psychologists argue that Dr. Miller's courtship theory does
not do full justice to another important dimension of music, its role in
cementing
social relationships and coordinating the activities of large groups of
people. Dr. Robin Dunbar, of Liverpool University, has shown that
monkeys spend
a large amount of time grooming other members of their social group, so
much so that they would scarcely have time to look for food if their
50-strong
groups were to grow any larger.

Dr. Dunbar believes that the much larger human groups, of 150 members or
so, overcame the grooming barrier by developing a new kind of social
glue,
namely language. Group singing, or chorusing, may have been an
intermediate step in this process, he suggests. He has preliminary
evidence that singing
in church produces endorphins, a class of brain hormone thought to be
important in social bonding, he said in an e-mail message.

Others, like Dr. Edward Hagen of Humboldt University in Berlin and Dr.
Gregory A. Bryant of the University of California at Santa Cruz, believe
the
role of music in human evolutionary history was not to create social
cohesion but to signal it to rival groups. By putting on a better
song-and-dance
display, a group could show it had the coordination to prevail in a
scrap, and could thus avoid a fight altogether, they write in an article
available on the
Web.

Male chimpanzees sometimes chorus in a call known as a pant-hoot, though
usually to attract females to a new source of fruit they have found. For

human ancestors, musical displays of this kind "may have formed the
evolutionary basis for the musical abilities of modern humans," Dr.
Hagen and Dr.
Bryant write. The Pentagon's vigorous support of military bands — $163
million in 1997 — lends a certain resonance to this view.

The courting and social cohesion theories of music's origins assume that
there are structures in the human brain that have evolved specifically
to handle
music. If no such structures exist, then Dr. Pinker's theory or
something like it is correct.

A leading clue that points to music-specific structures, yet is so far
not conclusive, is that many features of music are universal as well as
apparently
innate, meaning present at birth. All societies have music, all sing
lullaby-like songs to their infants, and most produce tonal music, or
music composed in
subsets of the 12-tone chromatic scale, such as the diatonic or
pentatonic scales. Some of the earliest known musical instruments, crane
bone flutes from
the Jiahu site in China, occupied from 7000 to 5700 B.C., produce a
tonal scale.

Dr. Sandra Trehub, of the University of Toronto, has developed methods
of testing the musical preferences of infants as young as 2 to 6 months.
She
finds they prefer consonant sounds, like perfect fifths or perfect
fourths, over dissonant ones. A reasonable conclusion is that "the
rudiments of music
listening are gifts of nature rather than products of culture," she
wrote in the July issue of Nature Neuroscience.

But although certain basic features of music, such as the octave,
intervals with simple ratios like the perfect fifth, and tonality, seem
to be innate, they are
probably not genetic adaptations for music, "but rather appear to be
side effects of general properties of the auditory system," conclude two
Cambridge
scientists, Josh McDermott of the Massachusetts Institute of Technology
and Dr. Marc Hauser of Harvard, in an unpublished article.

The human auditory system is probably tuned to perceive the most
important sounds in a person's surroundings, which are those of the
human voice.
Three neuroscientists at Duke University, Dr. David A. Schwartz, Dr.
Catherine Q. Howe and Dr. Dale Purves, say that on the basis of this cue
they may
have solved the longstanding mysteries of the structure of the chromatic
scale and the reason why some harmonies are more pleasing than others.

Though every human voice, and maybe each utterance, is different, a
certain commonality emerges when many different voices are analyzed. The
human
vocal tract shapes the vibrations of the vocal cords into a set of
harmonics that are more intense at some frequencies than others relative
to the
fundamental note. The principal peaks of intensity occur at the fifth
and the octave, with lesser peaks at other intervals that correspond to
most of the 12
tones of the chromatic scale, the Duke researchers say in an article
published last month in the Journal of Neuroscience. Almost identical
spectra were
produced by speakers of English, Mandarin, Persian and Tamil.

The Duke researchers believe the auditory system judges sounds to be
pleasant the closer they approximate to this generalized power spectrum
of the
human voice. "A musical tone combination whose power is concentrated at
the same places as a human speech sound will sound more familiar and
more
natural," Dr. Schwartz said.

Some people are unable to appreciate music, raising the question of
whether some music-specific faculty has been damaged. People who are
tone deaf
also fail to hear pitch changes in the human voice, so this deficit does
not seem specific to music. Some patients have music agnosia, an
inability to
recognize familiar melodies, even ones to which they know the lyrics.
But the brain has to store memories about music somewhere, and the music
agnosia
patients could have incurred memory damage that just happened to hit the
music archive, Mr. McDermott, of M.I.T., said.

"Any innate biases on music must derive from something in the brain, but
at present there is little evidence for neural circuitry dedicated to
music," Mr.
McDermott and Dr. Hauser conclude.

Dr. Zatorre, of the Montreal institute, takes a similar view. The brain
has evolved faculties for perceiving sounds, organizing events in time
and
maintaining memory stores, he said. "Once you've got all that hardware
in place, it can be used for a lot of different purposes. But I don't
think it follows
that music was selected for."

Whether music is cheesecake, courtship or cohesion, its mystery remains
unbreached.