by Alex Boese
Consider the implications of this. An almost ten-point leap in IQ—albeit a temporary one, as the effect seemed to fade away after fifteen minutes—just by listening to Mozart. Getting smart fast had never been so easy.
These results got people’s attention. Soon the “Mozart Effect,” as it came to be known, was being tested in all kinds of situations.
High school students started playing Mozart while studying for exams. University of Texas scientists combined Mozart’s music with whole-body vibrotactile stimulation to see if this would enhance the effect—it didn’t. A Texas prison made inmates listen to the composer during classes. Rauscher, in a follow-up experiment, claimed Mozart’s music improved maze learning in rats. Korean gardeners declared they had a season of spectacular blossoms after playing Mozart in a field of roses. Finnish researchers looked into whether the effect improved the memory skills of monkeys. To their surprise, Mozart actually had a negative effect. Our primate cousins evidently aren’t classical-music lovers.
Scientists also considered the work of other composers. The original researchers theorized that the complexity of Mozart’s music somehow stimulated neurons in the cortex of the brain. They explained that “we chose Mozart since he was composing at the age of four. Thus we expect that Mozart was exploiting the inherent repertoire of spatial-temporal firing patterns in the cortex.” The work of other “complex” musicians—such as Schubert, Mendelssohn, and, of all people, Yanni—was found to share Mozart’s enhancing properties. Noncomplex, unenhancing musicians included Philip Glass, Pearl Jam, and Alice in Chains.
But popular interest in the phenomenon didn’t really explode until word got out that a little bit of Mozart could increase infant intelligence. Ambitious parents, eager to have a junior genius, promptly went Mozart mad. Mozart-for-baby CDs rocketed to the top of the charts. The sounds of the composer began to be piped into nurseries. Zell Miller, governor of Georgia, ordered that Mozart CDs be distributed to all infants born in the state, and the state of Florida passed a law requiring classical music be played in state-funded day-care centers.
The curious thing was that not a single experiment had ever suggested a link between listening to Mozart’s music and increased infant intelligence. The closest an experiment had come to making this connection was a 1997 study, again by Rauscher, that demonstrated a relationship between piano lessons and improved spatial-reasoning skills among preschoolers. Learning to play the piano, of course, is not the same as listening to a CD.
The massive amount of popular interest in the Mozart Effect prompted the scientific community to take a closer look at the phenomenon. That’s when the theory began to hit rocky ground. Many researchers reported a failure to replicate the results of the 1993 study. In response, the UC Irvine team clarified that Mozart’s music did not appear to have an effect on all forms of IQ, but rather on spatial-temporal IQ, the kind that applied to paper folding and cutting tasks. In other words, millions of parents were unwittingly priming their children to become master scrapbookers. But even with this narrower focus, other labs continued to report a failure to replicate the results.
In 1999 and 2000 two researchers, Christopher Chabris (whom we just met in the invisible-gorilla experiment) and Lois Hetland, separately analyzed all the experimental data on the Mozart Effect. Both concluded that while a temporary effect did appear to exist, it was negligible. As for its application to children, Hetland bluntly dismissed this:
The existence of a short-lived effect by which music enhances spatial-temporal performance in adults does not lead to the conclusion that exposing children to classical music will raise their intelligence or their academic achievement or even their long-term spatial skills.
These negative results threw some cold water on the Mozart Effect’s scientific credibility, but they hardly dimmed its mass-market popularity. A sprawling self-help industry continues to promote the benefits of Mozart via books, CDs, Web sites, and countless baby toys. One entrepreneur, who has trademarked the term Mozart Effect, even claims the composer’s music has medical benefits. He tells how he dissolved a large blood clot behind his eye by humming it away. That sound you hear now is Mozart turning over in his grave.
Rauscher, F. H., G. L. Shaw, & K. N. Ky (1993). “Music and Spatial Task Performance.” Nature 365: 611.
The Acoustics of Cocktail Parties
With a drink gripped precariously in one hand, you lean closer toward your fellow guest. “What did you say?”—“I really don’t know what she sees in him.”—“Beg your pardon?”—You lean closer still. More people are arriving fast. The background murmur of voices is rising to a din. It’s growing harder by the minute to hear anyone at this cocktail party. “I said, I REALLY DON’T KNOW WHY SHE GOES OUT WITH HIM.”
In January 1959 William MacLean theorized in the Journal of the Acoustical Society of America that as any cocktail party grows in size there will arrive a moment when the gathering abruptly ceases to be quiet and becomes loud. This is the moment when guests start to crowd together and raise their voices to be heard above the background noise. He produced a mathematical formula to predict exactly when this would occur:
In this formula N is the number of guests at the party, K the number of guests per conversational group, a the sound absorption coefficient of the room, V the room volume, h the “properly weighted mean free path . . . of a ray of sound through the room,” do the minimum conventional distance between talkers, and Sm the minimum signal-to-noise ratio required for intelligible conversation. To calculate the maximum number of guests compatible with a quiet party, solve for No. Quite simple, really.
Acoustical researchers were not about to let MacLean’s hypothesis go untested. Throughout the remainder of 1959 the staff of the Division of Building Research of the National Research Council of Canada fanned out at cocktail parties, acoustical equipment in hand, to gather experimental evidence that would either confirm or refute MacLean’s theory.
The investigators admitted a few of the gatherings they monitored may have seemed like regrettable choices, in light of the nature of the research. For instance, collecting data at a cocktail party attended entirely by librarians, “a group dedicated professionally to maintaining quiet,” would seem to defeat the purpose. However, they insisted the librarians were actually quite raucous.
MacLean’s theory predicted “an abrupt 15-dB transition at the critical point.” This was not experimentally confirmed. Instead, noise levels rose steadily. There was no evidence of an abrupt transition point. The NRC scientists suggested MacLean’s formula failed to factor in phenomena such as appreciative laughter and wide variability in the speech power of talkers.
Of course, this entire line of research assumed cocktail parties populated by well-mannered guests who did not have to compete with blaring music. At parties where music is blasting, such as the typical college party, the research of Charles Lebo, Kenward Oliphant, and John Garrett would be of more use. During the 1960s these three doctors investigated acoustic trauma from rock-and-roll music by measuring sound levels at “typical San Francisco Bay Area rock-and-roll establishments frequented almost exclusively by teenagers and young adults, of whom many fall into a group popularly designated as ‘hippies.’ ” They discovered sound levels far in excess of those considered safe. They made the following suggestion to the hippies:
Attenuation of the amplification to safe levels would substantially reduce the risk of ear injury in the audience and performers and, in the opinion of the authors, would still permit enjoyment of the musical material.
The hippies would have heeded the warning—really, they would have—but the music was too loud to hear what the doctors were saying.
Legget, R. F., & T. D. Northwood (1960). “Noise Surveys of Cocktail Parties.” Journal of the Acoustical Society of America 32 (1): 16–18.
CHAPTER THREE
Total Recall
Memory, the theme of this chapter, is an ancient obsession. For millennia people have tried to find w
ays to increase it, delete it, or hold on to what they have. In the sixteenth century, an Italian inventor named Giulio Camillo claimed to have designed a Theater of Memory that enabled scholars to memorize all forms of knowledge, in their entirety. The Memory Theater was supposed to be a physical structure, although whether it was ever built or merely existed as plans on paper is not known. A scholar would stand inside the theater and see arrayed before him tiers of wooden shelves bearing cryptic images, each of which represented a form of knowledge. Studying the location and meaning of these images, Camillo claimed, would allow vast amounts of information to somehow, magically, flow into the savant’s brain. Needless to say, there is no evidence this worked. In the modern world, Hollywood has envisioned equally fantastic memory-altering technologies. For instance, there was the Neuralizer, carried by the government agents in the Men in Black films, that erased the memory of anyone who stared into its flash; or the Rekall mind-device machine, from the Arnold Schwarzenegger movie Total Recall, that allowed people to take imaginary adventures by implanting false memories of what they had done. In real life, scientific researchers have not yet achieved the kind of total memory control artists have dreamed of, but not for lack of trying.
Electric Recall
Wilder Penfield is poking around in your head—literally. You lie in an operating room. The top of your skull has been cut away, revealing your brain. But you are still awake. If there was a mirror on the ceiling, you could see the Canadian neurosurgeon moving behind you. Penfield lifts up an instrument, a monopolar silver-ball electrode, and touches it to your brain. You cannot feel this, because there are no nerve endings in the brain. But suddenly a memory flashes before your eyes, something you hadn’t thought of in years. You see your mother and father standing in the living room of the house you grew up in, and they’re singing. You listen closely. It’s a Christmas carol. “Deck the halls with boughs of holly, fa-la-la-la-la, la-la-la-la.” The tune is so clear you can hum along with it. You start to do this, but just then Dr. Penfield removes the electrode, and the memory vanishes as quickly as it appeared.
The phenomenon you have just experienced is electric recall. While performing brain surgery on epileptic patients during the 1930s and 1940s at the Montreal Neurological Institute, Penfield discovered that sometimes, when he touched an electrode to their brains, random memories would intrude into their conscious thoughts. It was as though he had found the mind’s videotape archive. When he pushed the magic button, zap, scenes from the patients’ pasts would start playing. Penfield himself used this analogy: “Applying the stimulus was like pressing the start button on a tape recorder. Memories would start playing before the patient’s eyes, in real time.”
Penfield was poking around in these brains to orient himself during the surgical procedure—because everyone’s neurons are wired a little differently—as well as to locate damaged regions. He would touch his electrode directly to a region, such as a wrinkle on the temporal lobe, and ask the patient what sensation, if any, she felt. Then he would stick a numbered piece of paper on that spot. When he was finished he took a picture of all the little pieces of paper. The resulting photo served as a convenient map of the patient’s brain he could then refer to as he worked. Kind of like surgery by numbers.
The first time one of his patients reported spontaneous memory recall was in 1931. He was operating on a thirty-seven-year-old housewife. When he stimulated her temporal lobe with an electrode, she suddenly said that she “seemed to see herself giving birth to her baby girl.”
Penfield was sure he had stumbled upon evidence of a memory library within the brain. He imagined it as “a permanent record of the stream of consciousness; a record that is much more complete and detailed than the memories that any man can recall by voluntary effort.” He began a systematic search for this memory library in other patients. Over a period of more than twenty years, he touched his electrode to hundreds of exposed brains, prompting subjects to report a variety of memories. These memories included “watching a guy crawl through a hole in the fence at a baseball game”; “standing on the corner of Jacob and Washington, South Bend, Indiana”; “grabbing a stick out of a dog’s mouth”; “watching a man fighting”; “standing in the bathroom at school”; and “watching circus wagons one night years ago in childhood.”
It was as though Penfield were Albus Dumbledore of Harry Potter fame, dipping his magic wand into a Pensieve and pulling out stray, glittering thoughts. The science fiction quality of all this was not lost on author Philip K. Dick. In his novel Do Androids Dream of Electric Sheep?, later adapted for the screen as Blade Runner, characters use a device called a Penfield Mood Organ to dial up emotions on command. (Dick also wrote the novel on which the movie Total Recall was based.)
Penfield’s discovery generated excitement during the 1950s, when he first publicly revealed his findings. Some hailed it as clinical confirmation of the psychoanalytic concept of repressed memories. But as time wore on, the scientific community grew more skeptical. Other neurosurgeons failed to replicate Penfield’s results. In 1971 doctors Paul Fedio and John Van Buren of the National Institute of Neurological Diseases and Stroke in Maryland stated bluntly that, in their extensive work with epileptic patients, they had never witnessed the phenomenon Penfield had reported. Brain researchers noted that it was definitely possible to provoke brief hallucinations by means of electrical stimulation of the brain, and experimenters such as Elizabeth Loftus of UC Irvine, whom we shall meet again in a few pages, built on this observation to argue that Penfield must have mistaken such hallucinations for memories. Basically, not many brain scientists today take seriously Penfield’s idea of a complete memory library hidden in our brain.
Still, it would be cool if Penfield were right and we could access everything we had ever seen or heard. We could press a button on a remote control and remember where we parked our car, or what we were supposed to buy at the supermarket. The only problem is that we’d still end up forgetting where we put the remote.
Penfield, W., & P. Perot (1963). “The brain’s record of auditory and visual experience.” Brain 86: 595–696.
Elephants Never Forget
An elephant walks into a bar and challenges the bartender to a memory contest. “Loser pays for the drinks,” says the elephant. What should the bartender do?
Before answering, the bartender might want to consider the elephant-memory experiments of Bernhard Rensch. During the 1950s Rensch explored the relationship between brain size and intelligence in the animal kingdom. This led him to conduct a series of tests on a five-year-old Indian elephant at the Münster Zoological Institute, of which he was the director. His results suggested that while it’s not literally true that elephants never forget, they do have excellent memories.
Rensch started with a simple test. He presented the elephant (never identified by name) with two boxes, each marked by a different pattern, a cross or a circle. Would she remember that the box with the cross on its lid always contained food? It took her a while, over 330 tries, but eventually she figured it out. Rensch helped her by screaming “nein!” every time she chose the wrong box. Once she got the idea, she really got the idea. From then on she consistently chose the cross over the circle.
Rensch next introduced her to new pairs of positive (food) and negative (no food) patterns: stripes, curvy lines, dots, etc. Now that she understood the game, she was on a roll. She quickly mastered twenty pairs, a total of forty symbols. In a test using all the symbols, given in random order, she chose the correct pattern almost six hundred times in a row. Many humans would be hard-pressed to do as well.
The elephant could also pick out the correct box from a choice of three negative patterns and a positive one. However, when Rensch presented her with a negative-patterned box and a box with a blank lid (neither of which contained food), she got mad, tore the lids off the boxes, and trampled them. Apparently, elephants don’t like trick questions.
The hardest test was yet to come. Rensch waited a ful
l year and showed the elephant thirteen of the symbol pairs she had previously learned. She immediately recognized them. In 520 successive trials, she scored between 73 and 100 percent on all the pairs except one, a double circle versus a double half circle. And even on that pair she scored 67 percent. Rensch declared it to be “a truly impressive scientific demonstration of the adage that ‘elephants never forget.’ ”
Science can’t generalize about an entire species based on a sample of one. Perhaps Rensch’s subject happened to be a genius. However, similar tests have confirmed the remarkable recall of elephants.
In 1964 Leslie Squier trained three elephants at the Portland Zoo to distinguish between lights of different color. They received a sugar cube as a reward for a correct response. Eight years later Hal Markowitz salvaged Squier’s equipment from a scrap heap and retested the elephants. One of them, Tuy Hoa, walked right up and gave the correct answers. She clearly remembered the test. The other two elephants didn’t perform as well. But when Markowitz examined them he realized there was a reason for this. They were almost blind and couldn’t see the lights.
Given all this, how does our bartender respond to the challenge? Simple. He throws the elephant out on its trunk.
The elephant: “Why did you do that?”
The bartender: “Because you never paid your bill last time you were in here.”
The elephant: “That was three years ago. I didn’t think you would remember.”
The moral: Bartenders never forget, either.