The Mozart Effect
Can the beautiful music of one of
Europe's greatest composers really help you think better,or even soothe a
broken brain? Gary Kliewer investigates
LISTENING to Mozart boosts your brain power. At least that's
the theory that sent a certain CD soaring to the top of the classical bestsellers
list on Internet bookstore Amazon.com.
Music for The Mozart Effect Vol 1-Strengthen the Mind also cracked
Billboard magazine's classical top ten, where it was joined by a second
disc, The Mozart Effect: Music for Children Vol 1-Tune Up Your Mind.
The excitement started six years ago when researchers reported that people scored better on a standard IQ test after listening to Mozart. But last summer, this "Mozart Effect" suffered a setback when several sceptics repeated the original study but failed to find any improvement.
This is not the end of the story; though. A closer look shows that Mozart's music does have a profound effect on the brain, though no one yet knows why. Rats raised on Mozart run through mazes faster and more accurately. People with Alzheimer's disease function more normally if they listen to Mozart and the music even reduces the severity of epileptic seizures.
The first hint of the Mozart Effect emerged more than a decade ago from early efforts to model brain activity on a computer. In simulations by neurobiologist Gordon Shaw at the University of California at Irvine, the way nerve cells were connected to one another predisposed groups of cells to adopt certain specific firing patterns and rhythms. These natural patterns, he believes, form the basic grammar of mental activity. In 1988, Shaw and his student Xiaodan Leng decided to turn the output of their simulations into sounds instead of a conventional printout. To their surprise, the rhythmic patterns sounded like baroque, new age, or Eastern music. "I don't mean it was great music, but we got distinct, recognisable styles," Shaw says.
If brain activity can sound like music, Shaw wondered, might we learn to understand the neural grammar by working backwards and watching how the brain responds to music? In other words, might patterns in music somehow prime the brain by activating similar firing patterns of nerve clusters?If so, Shaw thought he knew where to start: Mozart, a prodigy who began composing at age four "We thought if anyone might be tapping into this inherent neural structure, it might be Mozart," says Shaw.
So Shaw and his colleague Frances Rauscher, now a psychologist at the University of Wisconsin at Oshkosh, decided to use part of a standard IQ test to see whether Mozart's music could temporarily boost people's ability to visualise shapes. This ability forms the basis of many complex thinking skills that involve turning an object over in your mind, including much of mathematics.
In their largest study, published in 1995, Shaw and Rauscher asked 79 college students to work out what a paper would look like if folded and then cut like a paper doily. After taking this test one group of students sat in silence for ten minutes. Another group listened to a Mozart piano sonata, while a third group heard either an audiotaped story or minimalist, repetitive music. Then they all took the test again. The Mozart group correctly predicted 62 per cent more shapes on the second test, while the "silent" group improved by 14 per cent and the third group by just 11 per cent.
It is this experiment which has drawn so much criticism from other researchers. Kenneth Steele, a psychologist at Appalachian State University in Boone, North Carolina, repeated the experiment but found no sign that Mozart's music improved the scores of 125 subjects, even when he scoured individual scores for signs of improvement (Psychological Science, vol 10, p 366).
At Harvard University, psychologist Christopher Chabris looked at results from 16 studies hunting for the Mozart Effect, involving a total of 714 subjects. When he analysed all the studies as a group, he found no benefit from listening to Mozart. He concluded that the real reason some people do better is what psychologists call enjoyment arousal"-music improves people's mood, so they perform better.
|Slow movement: The brain waves of a severe epileptic are calm during Mozart (top) but stormy during silence (bottom)|
But the critics are only looking at part of the story, says
Lois Hetland of the Harvard Graduate School of Education. Chabris summarised
only experiments that compared Mozart against silence, not against other
compositions. Hetland, who was agnostic about the Mozart Effect, cast a broader
net that included every study to date, a total of 1014 subjects.
She found that Mozart listeners outperformed other groups more often than could be explained by chance, although the effect was usually much weaker than Shaw and Rauscher saw. Even these small effects are impressive, says Hetland, because so many factors could obscure them "In the early stages of research in a field, we would expect the measured effect to be small until we learn to separate the signal from the noise in the research method," she says. For example, Mozart may give a bigger boost to some people than to others, depending on their sex, musical tastes and training, spatial ability and cultural background.
Note of discord
|THE popular idea that classical music can
improve your maths is falling from favour. New
experiments have failed to support the widely publicised finding that Mozart's
music promotes mathematical thinking.
Researchers reported six years ago that listening to Mozart brings about short-terrn improvements in spatial-temporal reasoning, the type of thinking used in maths. Gordon Shaw of the University of California at Irvine and Frances Rauscher of the university of Wisconsin in Oshkosh had asked students to perform spatial tasks such as imagining how a piece of paper would look if it were folded and cut in a certain pattern.
Some of the students then listened to a Mozart sonata and took the test again. The performance of the Mozart group improved, Shaw found. He reasoned that listening to Mozart increases the number of connections between neurons.
But Kenneth Steele of Appalachian State University in North Carolina learnt that other studies failed to find this effect. He decided to repeat one of Shaw's experiments to see for himself.
Steele divided 125 students into three groups and tested their abilities to work out how paper would look if cut and folded. One group listened to Mozart, another listened to a piece by Philip Glass and the third did not listen to anything. Then the students took the test again.
No group showed any statistically significant improvement in their abilities (Psychological Science, vol 10, p 366). Steele concludes that the Mozart effect doesn't exist. "It's about as unproven and as unsupported as you can get," he says.
Shaw, however, defends his study. One reason he gives is that people who perform poorly in the initial test get the greatest boost from Mozart, but Steele didn't separate his subjects into groups based on ability. "We're still at the stage where it needs to be examined," Shaw says. "I suspect that the more we understand the neurobiology, the more we'll be able to design tests that give a robust effect."
[New Scientist 31July 1999]
Another converted sceptic is psychologist Eric Seigel at Elmhurst College, Illinois, who set out to disprove the Mozart Effect by using a different spatial reasoning test. In his test, a subject looks at two letter E's, with one rotated at a skewed orientation in relation to the other. The greater the angle, the harder it is to judge whether the letters are the same or different. The milliseconds it takes the subject to make that judgment are a precise measure of spatial reasoning. To Seigel's surprise, subjects who took the test after listening to Mozart did significantly better, which Seigel says is in line with Rauscher's results in the original paper-folding test. "It was as though they had practised the test," says Seigel. "Now we have another way to measure the Mozart Effect." Next, he plans to try other experimental designs that may make the effect stand out even more.
For the sake of consistency, almost all studies on the Mozart Effect so far have focused on a single piece of music, the Sonata for Two Pianos in D Major (K 448), though some have measured the effect from other music as well. "It is not just this composition, and not just Mozart," says Rauscher. However, the researchers don't know why the Sonata in D works or which other pieces might. Would the music of Mozart's contemporary Johann Christian Bach work, or even a 20th-century composer such as Igor Stravinsky? One study did show that the music of a popular New Age composer, Yanni, had an effect.
Critics take issue with this vagueness, saying that someone has to define what specific musical elements are required. "They have never specified what it was about that music, so when other laboratories don't get the effect, they can always say it wasn't the right music," says Steele.
Studies yet to be published may help clear up this problem. At the University of Illinois Medical Center, neurologist John Hughes and a musicologist colleague have analysed hundreds of compositions by Mozart, Chopin and 55 other composers. They devised a scale that scores how often the music's loudness rises and falls in surges of 10 seconds or longer.
Minimalist music by the composer Philip Glass and pop tunes scored among the lowest on this measure, he found, with Mozart scoring two to three times higher. Hughes predicts that sequences repeating regularly every 20 to 30 seconds may trigger the strongest response in the brain, because many functions of the central nervous system, such as the onset of sleep and brain wave patterns, also occur in 30-second cycles. And of all the music analysed, Mozart most often peaks every 30 seconds, Hughes found. Results such as these may help predict which pieces of music have the strongest effect on the brain, says Hughes, who hopes to begin testing brain response soon.
Meanwhile, another of Shaw's collaborators, Julene Johnson of the Institute of Brain Aging and Dementia at the University of California at Irvine, gave Shaw's original paper-folding test to Alzheimer's patients, who often have impaired spatial reasoning because of their illness. In a pilot study, one patient's scores improved by 3 or 4 correct answers out of 8 test items after 10-minute doses of Mozart, but not after silence or popular music from the 1930s. "The popular tune was familiar to the patient and intended to account for a possible emotional effect of music versus silence," says Johnson. She has now followed up with a group study comparing Mozart versus silence in 18 patients. Though results are not yet published, Mozart did improve the patients' test scores, especially in people who showed little improvement after practising the test.
Even stronger support for Mozart's effect on the brain comes from other studies. Rauscher, for example, subjected 30 rats to 12 hours of the Sonata in D daily for over two months. (Pity the poor laboratory staff!) These rats ran a maze an average of 27 per cent faster and with 37 per cent fewer errors than 80 other rats raised with white noise or in silence, she found. And this improvement can't be due to enjoyment arousal, because rats have no emotional response to Mozart. Instead, the study suggests a neurological basis for the Mozart Effect, says Rauscher.
Steele, a specialist in animal learning, is not convinced. After all, he says, a rat's brain is organised to respond to rat-squeak sounds, not European music. "What is the line of reasoning that rat brains respond the same way as humans? There is nothing in terms of current evolutionary or psychological theory that suggests there would be a related effect on rat brains. It is a great speculative leap," he says.
Rauscher does acknowledge that Mozart may simply give the rats a richer, more stimulating environment, something the rats could also get from other distractions or activities. "The control group rats are severely deprived-an extreme condition," she admits. She has begun a new study comparing rats with the heavy Mozart diet to rats given plenty of social interaction and toys in their cages.
Still, there must be something special about Mozart's music, and not just for rats. Hughes studied 36 severely epileptic people who suffered almost constant seizures that sometimes left them comatose. For 29 of those patients, the debilitating electrical storms that swept their brains became smaller and less frequent shortly after he began playing Mozart (see Diagram). The same patients showed no improvement while they listened to a Glass composition, 1930's pop tunes, or silence. "Sceptics could criticise the IQ studies," Hughes says, "but this is on paper: you can count discharges and watch them decrease during the Mozart music." And in comatose patients, at least, the effect cannot be dismissed as an enjoyment arousal.
Another study, by Shaw and neurobiologist Mark Bodner of the University of California at Los Angeles, used magnetic resonance imaging (MRI) to map the regions of a subject's brain that respond while listening to Mozart, '30s pop music, or Beethoven's Für Elise. Not surprisingly, Bodner found that all music activates the auditory cortex, where the brain processes sound, and sometimes triggers parts of the brain that are associated with emotion. "But with Mozart, the whole cortex is lighting up," Bodner says. Specifically, only Mozart also activates areas of the brain involved in fine motor coordination, vision, and other higher thought processes, all of which might be expected to come into play for spatial reasoning.
Unfortunately, an MRI scan won't tell you anything about how a person may respond to the music. "I don't doubt that music affects the brain, even beyond auditory cortex-it must," responds Chabris. But he doubts those measurable effects actually cause any of the changes in spatial reasoning or other abilities. But these short-term improvements may not be Mozart's most important effect on the brain. In a five-year study with children, Rauscher has found that keyboard music training improves skills that require mental imagery-and after two years of lessons, the effect doesn't wear off. "All of the Mozart Effect experiments are based on the idea that the brain can be anatomically influenced by music. With children it may be actually building the neural network," says Rauscher. In other words, a childhood rich in music may have lasting benefits. This may be finally where the Mozart Effect makes its real encore.
Gary Kliewer is a freelance science writer living in Ashland, Oregon
Keeping Mozart In Mind by Gordon Shaw (Academic Press,
1999). "Listening to Mozart enhances spatial-temporal reasoning: towards
a neurophysiological basis" by Frances Rauscher and others, Neuroscience
Letters vol 184, p44(1995). "Prelude or requiem for the Mozart effect?" by
Christopher Chabris, Nature, vol 400, p826 (1999). 'The 'Mozart Effect' on
Epileptiform Activity" by John Hughes and others, Perceptual and Motor Skills,
vol 86, p 835 (1996).