In January, 1998, Governor Zell Miller proposed an interesting component for Georgia’s state budget. He allocated 105,000 dollars of the state’s 12.5 billion dollar budget to providing every infant born in the state with classical music. He stated, “No one questions that listening to music at a very early age affects the spatial, temporal reasoning that underlies math and engineering and even chess” (1). Governor Miller’s belief that classical music stimulates brain development of infants and young children is just one example of the so called “Mozart Effect”. Alfred A. Tomatis, a French researcher who wrote a book titled Porquois Mozart? (Why Mozart?) in 1991 proposed that Mozart’s music could retrain the ear and promote brain development when heard at differing frequencies (2). The idea became popularized in 1997 with Don Campbell’s book, The Mozart Effect: Tapping the Power of Music to Heal the Body, Strengthen the Mind, and Unlock the Creative Spirit, which claimed that listening to Mozart can temporarily increase mental ability; as a result, parents should play classical music to their infants in order to increase their brain development (3). Campbell based the claims in his book on the 1993 experiment performed by researchers Frances Rauscher, Gordon Shaw, and Catherine Ky of the University of California Irvine (4). In this experiment, thirty-six college students were exposed to a Mozart sonata, a relaxation tape, or silence, and then they were given IQ spatial reasoning tests after each exposure. The students performed better on the tests after listening to Mozart, and consequently, this short-term improvement in spatial reasoning is what is now considered the Mozart effect (4).
The widely popularized version of the Mozart effect affects much more than just the spatial reasoning tested in the Rauscher study; the idea that “music makes you smarter” has become the popular mantra, resulting in actions such as Governor Miller’s classical music initiative. He is not the only one; one simply has to browse the nearest bookstore or go online in order to find products and CDs geared to exposing infants to classical music, which supposedly provides enriched sensory stimulation, leading to better brain development. In a nutshell, these products want parents to believe that classical music makes babies smarter (5). Although the idea that classical music can make humans more intelligent is a nice one, it is not so simple. Researchers have tried and failed to reproduce the original Mozart effect, while others have supported the effect with their experiments. The validity of the original experiment has been questioned and criticized by other scientists. There is also the question of whether classical music affects childhood development in the ways that Don Campbell and Zell Miller claimed. Can music actually make humans smarter, or is this just an over-generalized claim made by entrepreneurs in their efforts to make money? To answer this question, evidence from both the supporters of the Mozart effect and its critics needs to be analyzed and discussed.
Cause-Effect Relationship in Myth
Research Supporting the Mozart Effect
The 1993 study performed by Shaw, Rauscher, and Ky of the University of California, Irvine is considered the original Mozart effect experiment. Published in Nature magazine, the study, titled “Music and Spatial Task Performance,” examined thirty-six college-aged students (4). The subjects were given three sets of standard IQ spatial reasoning tests taken from the Stanford-Binet intelligence scale, the standard for intelligence testing. Before the subjects took each test, they were exposed to 10 minutes of Mozart, relaxation instructions, or silence. The musical piece was Mozart’s Sonata for Two Pianos in D Major. All of the subjects were exposed to each condition and took each test, which consisted of a pattern analysis test, a multiple-choice matrices test, and a multiple-choice paper-folding and cutting test. The experimenters scored the tests by first subtracting the number of items failed from the highest item number administered, and then converting these raw scores to Standard Age Scores (SAS) using the Stanford – Binet’s SAS conversion table of normalized standard scores. Standard age scores take into account the subjects’ ages in addition to their raw scores. After establishing this, the researchers determined Intelligence Quotient (IQ) equivalents by multiplying each SAS by three (the number of subtests) and then using an area score conversion table to attain the final scores. The mean standard age scores were 57.56, 54.61, and 54.00 for the music, relaxation, and silent conditions respectively . The translated spatial IQ scores were 119, 111, and 110 respectively (4). In addition, the researchers took the pulse rates of the subjects before and after each listening condition; further variance tests ruled out arousal as a factor in the results. Furthermore, they found that the music’s effect was brief, only lasting around ten to fifteen minutes. However, the researchers did not include a set delay period between the conditions and the tests, so they did not determine if the increased spatial reasoning effect could decay over time. Rauscher, Shaw, and Ky suggested that the complexity of Mozart’s composition was what stimulated the brain, resulting in the higher IQ performances; they also predicted that music lacking complexity would not enhance but possibly interfere with abstract reasoning (4). It was these conclusions that led to the widespread claims that classical music can improve brain function.
One of the applications of the Mozart effect is its supposed potency in childhood development. Don Campbell claimed in his book that sensory stimulation of classical music leads to increased neural connections, benefitting child development (3). Studies have indeed suggested that sensory stimulation is essential in infant development. The 1963 landmark study done by Harvard neurobiologists Torsten N. Wiesel and David H. Hubel titled, “Effects of Visual Deprivation on Morphology and Physiology of Cells in the Cat’s Lateral Geniculate Body” was one of the first studies to analyze the critical period in infant animal development (6). In their experiment, Wiesel and Hubel used nine kittens and one adult cat. Four of the cats were in the complete sensory deprivation group, meaning that their right eyelids were sewn shut just before normal eye opening, blocking the kittens from seeing any type of form or light. The duration of deprivation for these kittens ranged from nine to thirteen weeks. The experimenters also deprived two kittens of sight in their right eyelids at nine weeks old, allotting these kittens some previous sensory stimulation. The durations of deprivation for these two kittens were either four or sixteen weeks. To ensure that the differences between sensory deprivation in adult cats and kittens could be accounted for, the experimenters sewed the right eyelid of an adult cat for a twelve week period. They also experimented with different types of visual deprivation by placing a plastic translucent occluder over the right eye of two, newborn kittens; the coverings, which showed a little more light than the sutured eyelids, were kept in place for either eight weeks or ten weeks. Finally, the ninth kitten had a similar occlusion with a nictitating membrane placed over its right eye at five weeks after birth. The duration of deprivation for this kitten was twelve weeks.
When the scientists removed the various coverings from the kittens’ eyes, they observed physical and functional changes in the kittens’ lateral geniculate bodies, which are structures that function to process neural signals sent from the retina of the eye to the occipital lobe of the brain. The kittens with the sutured eyelids from birth for three months had geniculate cells with decreased activity. Additionally, these cells fed by the deprived eyes had decreased areas of about 40 percent for the dorsal and middle layers. The nuclei and nucleoli of the geniculate bodies also shrank. The nine-week kittens that had closed lids for four to sixteen weeks had similar but less severe changes in the geniculate cells, and the translucent contact occluder placed on the newborn kittens for two to two and a half months also caused the cells to shrink. However, in the adult cat with a sutured eyelid and in the five-week-old kitten with the translucent occluder, there was no physical atrophy or decreased function in the geniculate cells. Wiesel and Hubel remarked that the fact that the atrophy was the most pronounced in kittens deprived from birth, less evident in kittens deprived at a later age, and absent in the deprived adult cat suggests that there is a critical period in the development of the nervous system in which an animal can more easily make new nerve connections (6). Advocates for the Mozart effect have cited this concept of a critical period of nervous development in their claims of music making babies smarter.
An experiment titled, “Improved Maze Learning Through Early Music Exposure in Rats,” was performed by Frances H. Rauscher (one of the original authors of the 1993 Mozart Effect study), K. Desix Robinson, and Jason J. Jens from the Department of Psychology of the University of Wisconsin (7). In this experiment, the Mozart effect was applied to learning in animals of a younger age. The experimenters randomly assigned ninety rats in utero to three exposure groups: a Mozart condition (Sonata for Two Pianos in D Major), a minimalist music condition (Philip Glass’ Music with Changing Parts), and a white noise condition. The in utero rats (forty five male and forty five female) were placed in three groups of thirty in three different exposure rooms, where the music was played on a continuous loop for twelve hours a day. The rats were exposed for approximately three weeks in utero, sixty days post-partum, and through the last days of testing. At sixty one days, ten rats from each exposure group were assigned to one of the three auditory maze exposure groups (Mozart, Glass, and white noise), in which the rats had to go through a maze while listening to each type of sound. Each trial ended after the rat reached the goal box at the end of the maze; blind testing was performed over five days, three trials a day. When the rats were placed in cages after testing, the music exposure continued. Data analysis found that the rats exposed to Mozart reached the goal box more rapidly and made fewer errors than rats exposed to Glass or white noise. The Mozart rats completed the maze in an average of 34.72 seconds, the Glass rats in 50.11seconds, and the white noise rats in 44.29 seconds. The Mozart rats were also found to have fewer errors while completing the maze, with an average of 2.0 errors per trial for the Mozart rats compared to 2.85 and 3.35 errors for the Glass and white noise rats, respectively. The maze exposure group was omitted from further data analysis because it was found that the cage exposure done prior to the testing was what had the largest effect on performance (7).
While these three experiments show a favorable relationship between Mozart music and enhanced intelligence, a deeper investigation of their implications and methods is necessary to properly asses the validity of their contributions to the overall popular portrayal of the “Mozart effect.” That is, do these studies indicate a permanent improvement of mental abilities?
Analysis of Evidence.
The original source for the concept of the Mozart Effect, the study performed by Shaw, Rauscher, and Ky, shows a clear relationship between the music of Mozart and spatial reasoning skills. On the surface it may seem to help the case for the idea that Mozart can make babies smarter, but this study is quite removed from this theory. Of note that there was no indication of any general improvement of intelligence as spatial reasoning was all that was tested, and thus is the only thing this experiment can link to Mozart. Also important to note is the temporary nature of the improvement observed. The media explanation of the Mozart Effect proposes that hearing classical music will make your child smarter. This study shows that this may occur but only for ten to fifteen minutes. One positive gain for the Mozart effect found in this study is that the researchers attempted to eliminate the obvious outside factor of arousal. By monitoring the subjects heart rate they were able to detangle the effects of Mozart from at least one extraneous variable, though there could always be some other unknown factor that links Mozart music and spatial reasoning.
The experiment performed by Wiesel and Hubel demonstrates an important anchor of the argument for the Mozart effect. What they were able to show was that there is a critical period of development during infancy that is dependent on external stimulation. This could be used to argue that the complexity of Mozart music could be used to provide the needed or extra stimulation to developing children in order to produce a more intelligent child. This would be pure extrapolation that is not supported by the study in any way. There are many reasons this study does not mesh perfectly with the Mozart effect and is a poor support for its argument. Wiesel and Hubel studied the effects of sensory deprivation on eyes. Their findings may not translate into other sensory organs. If they did and we accepted the idea that infants also require a degree of audible stimulation this study says nothing about the complexity or quantity required. There is no reason to assume that listening to Mozart would provide “better” stimulation than simply exposing the child to normal sounds.
The best support for the Mozart effect, both as the idea that Mozart increases spatial reasoning and can benefit children in very early infancy or in the womb, comes from the rat study done by Rauscher, Robinson and Jens. By exposing rats in utero and early infancy they were able to demonstrate the Mozart effect on infants which neither the original study did as their subjects were college aged nor the deprivation studies as they never demonstrated the Mozart effect. This study shows that the Mozart effect does occur in infants. By performing this test we can now better understand how Mozart might affect developing children rather than guess or assume based on tangentially related experiments. Though this experiment still does not cover longevity of the improvement shown by subjects. As the rats were continuously exposed to their treatments before and after each test their enhanced performance may be due to the short spanned enhancement demonstrated with in the original 1993 study and not indicative of any permanent improvement of IQ. The reduction of mistakes among rats that were exposed to Mozart may however suggest that spatial learning was increased which led to a better memory of the maze each repeat test.
Arguments against the Mozart Effect[a]
The Mozart effect is the purported increase in spatial intelligence -the ability to visualize objects in one’s mind in an expert manner including viewing it from different angles, in different shapes and sizes, after listening to Mozart’s K. 448. This effect has been overrated by the media in an effort to convince the public (especially mothers and pregnant women) that listening to Mozart makes one smarter. The catchphrase “Mozart effect” came about as a result of a study conducted by Rauscher, Shaw, and Ky which concluded that after listening to a piece by Mozart (Sonata for Two Pianos in D. Major K. 448), adult participants experienced a temporal increase in spatial intelligence in which their IQ scores went up[b] (8). A consequent documentation of this paper caused the misconception of what people believe will be an easy solution to increase their intelligence. Unfortunately this effect is a fallacy as has been proven by other papers that have attempted to either repeat the Mozart effect as is in adults, or in children. Investigators that tried to repeat the study to validate the “Mozart effect” have either reported a null effect of the musical stimuli on participants or a non-significant difference in IQ scores before and after the administration of the Stanford-Binet Paper Folding and Cut test.
The first study was a replication of the original study by Rauscher et al (in 1993), conducted in elementary schooled children ages 10 to 12. This paper sought to prove that the Mozart effect observed in adults cannot be applied to children (8). The researchers administered the experiment to children in a natural classroom environment with the elementary teachers acting as aids. During the first week after providing instructions for a pretest, they presented it to the children. A week later they provided the musical stimulus (which included silence, a popular music called Zorba’s dance, and Mozart’s K. 448), and then followed this with a post IQ test adjusted to suit children called the Fitzgerald paper folding test for the testing of any spatiotemporal enhancements. During their experiments, the investigators also tested for two factors which they believed could contribute to the children’s performance on spatiotemporal tasks which included: musical ability -an effect on spatiotemporal ability which in children which had been studied and well documented by other researchers, saying that children who study music or play musical instruments have a higher spatiotemporal functioning compared to non-musical children; and individual differences in spatiotemporal ability amongst children not owing to musical ability (8). The purpose of this additional testing was to control and minimize the contribution of other factors (than the musical stimulus) that could produce a “Mozart effect” (8). Parents were also asked to give accounts of their children’s musical background/training for the purpose of assessing the aforementioned musical ability. The results of this experiment showed that there was no increase in spatiotemporal ability in children. The researchers found that the children performed no differently after having been exposed to silence, Mozart, or the popular Zorba’s dance when comparing the posttest results to pre test results (8). Another interesting finding was that children with a musical ability performed better than those without a musical ability, suggesting a link between musical and spatiotemporal ability (8). The authors think this “musical ability” factor is partly responsible for the observed “Mozart effect” in other published studies since this factor has neither been measured nor accounted for in other studies (8). On the other hand, the authors have partially attributed the lack of a Mozart effect to developmental factors in children (8). They have based this assertion on previously documented studies which found that after listening to Mozart, adults experienced a “mood arousal” which enhanced their spatiotemporal abilities. The authors believe that the fact that children’s brains are still undergoing development in their frontal and parietal lobes (areas which are highly liked to spatiotemporal tasks) means that they cannot experience an arousal in mood after listening to Mozart – this paper found that children enjoyed listening to Mozart as much as they enjoyed listening to silence- and therefore the discrepancy in mood arousal after listening to K. 448 between adults and children could account for the lack of an observed Mozart effect in children (8). In any occasion, the Mozart effect observed in adults cannot be applied to children either because it is nonexistent or children’s brains are not fully developed to experience concomitant effects (such as arousal) that come with listening to music composed by Mozart. Therefore advertisement geared towards mothers and pregnant women hold false promises to help mothers raise their children to become more intelligent.
The next study conducted by Steele and Bass had a purpose of validating the results of the original study, and they accomplished this by replicating Rauscher et al’s 1995 original study (9). There were however a few adjustments made in this experiment including: the use of 125 participants as opposed to Rauscher et al’s 79, the limit of their number of post IQ test administrations to only one (as opposed to the original three) their reason being that the original study only had a substantial Mozart effect after its first post treatment (9), and they randomly assigned individuals to groups to create even groups as opposed to their using pretest administration for the purpose of putting the participants into groups of people with similar brain performance (9). One additional variable that was tested for in this study that was not in the original study was a mood and arousal effect, which the authors included because papers had been published suggesting that mood enhancement could produce a Mozart effect, therefore they wanted to distinguish the source of an enhanced spatiotemporal performance as either listening to Mozart’s K. 448 or an aroused state of mind (9). The results of this study found no significant difference in participants’ scores before and after exposure to the stimuli, a finding which differed notably from the original study conducted in 1995 (9). However, upon measuring mood and arousal, this study found that participants reported a tense and angry feeling after listening to the repetitive Glass composition in contrast to the calmness they felt after listening to Mozart, and a neutral feeling was reported for the silence condition (9). Nonetheless, in spite of the differing mood and arousal levels, there was no difference in IQ scores amongst the listening conditions, suggesting that mood does not affect spatiotemporal performance (9). This study, after accurately replicating the experiment from the original 1995 study, supported that the “Mozart effect” was unfounded, especially in the light of creating and commercializing products that enhance spatial temporal reasoning.
Thompson et al fully believed the Mozart effect was due to an increase in arousal, and therefore they contended that if this was the case then other tasks than music that produce arousal or enjoyment should similarly increase performance on spatiotemporal tasks (10). This negates the Mozart effect because it fully attributes any increase in spatiotemporal performance to mood and arousal not to Mozart music. Participants were separated into two groups, one which was exposed to Mozart’s K. 488, and the other to Albinoni’s track 1 (a sad depressive piece), and then each group was exposed to its assigned music, and then silence. There were three steps to the experimental process: first the investigators had the participants listen to either silence or music; then they were given a spatial task through the computer to complete; and lastly they were asked to rate their arousal following the musical piece and following silence, and also to rate their level of enjoyment following the musical piece only. The results revealed that the Mozart group performed better on IQ tests. They did however report higher levels of arousal and musical enjoyment, as opposed to the Albinoni group which performed lower on IQ tests, and which also reported negative moods such as sadness, gloominess, etc. This supports that a higher arousal rather than music leads to improved performance on various spatial tasks (10). The authors of this paper go on to describe other papers that have published a link between arousal and music, and find their results consistent with these other papers.
No clear cause and effect relationship between listening to Mozart and improved spatial performance has been made, only associations; neither has there been any clear measurement in areas of the brain that light up to attest to a reaction or a neural firing owing to the musical stimulus. Moreover positive findings -including the original study by Rauscher et al- lack the robustness that would allow the business industry to base products on this phenomenon as various studies have failed to repeat the positive findings. It then seems that all good things in life (including improved intelligence in specific areas) do not come easy. Simply listening to Mozart would not do the trick; one has to be actively engaged in activities that stimulates targeted areas of the brain. It has been investigated and documented that children who study music for extended periods enjoy these benefits as the study of music requires skills of memorization, concentration, and focused attention; these skills result in mastered performance, an understanding of musical pattern, as well as motor skills, all of which could highly develop brain areas associated with spatial tasks (11). It therefore seems to be a better option for parents to invest in music lessons for their children, as opposed to buying CD’s, to help improve spatial intelligence (11).
Designing the Perfect Experiment
In order to either prove or disprove this myth, it is our opinion as researchers that a longitudinal study would be most effective and would yield a valid, scientifically accurate result. In a longitudinal study, subjects are observed over long periods of time, ranging from a few months to many years. It is essential in a study of this sort to have a large sample size. This is because, despite its many benefits, a longitudinal study is still technically a correlational study, and cannot prove a cause-effect relationship. So, it must be carried out with the focus of minimizing influences other than those you are testing for, keeping as many factors constant as possible.
A longitudinal study is ideal for the myth we are trying to analyze because it would allow us to accurately assess brain development over time. In many preceding studies, this was the essential flaw; they failed to analyze brain development, instead only assessing brain activity in the short term. This distinction is important because, although they attempt to, other studies, like the original one by Shaw, Rauscher, and Ky, cannot truthfully speak to the implications of listening to music on the overall development of the child. And it is the overall development of the child that we believe parents are most interested in. Parents are willing to spend money on products that they think will enhance their child’s overall success in life, regardless of how ridiculous or expensive the product is. If that’s where the money is, then that’s what will be profitable to study.
For our study, we would need to assemble a group of at least six hundred pregnant mothers who are expecting their first child. First-time mothers would be preferable, because they would have the least bias in the “right” way to raise a child; they would all have the same experience level. Individuals would be chosen at random from a median socioeconomic group, in order to minimize the statistical advantage that children of one income level might have over another. Race and gender of children would be random; there would be no quotas in that regard, but it would be assumed that, with a sample size of six hundred individuals, ratios of race would at least resemble those of the overall population. Mothers selected would be no more than one trimester into their pregnancy, and would be modestly compensated for participation in the study.
Expecting mothers would be divided into three groups of two hundred subjects each. Group A would be the control group, comprised of mothers who have agreed not to play any special music for their child, before or after birth. They would be told to play no more music in the home than they did before they knew they were pregnant. Group B would be instructed to, starting in their second trimester, listen to classical music with their child for one continuous hour per week. From the second trimester on, Group C would play classical music for their child for one continuous hour every day. Music played for infants would be from a set of CDs pre-selected by the researcher. Groups B and C would continue this pattern of music listening with children from the second trimester through five years of age.
Children from all three groups would be assessed and observed by researchers on a monthly basis. Assessments would be observed by researchers but conducted by child development psychologists. These psychologists would be instructed to perform the same sets of studies and cognition test for each of the six hundred subjects and to assess empirically, given the child’s age, how normally they are developing. Obviously, “normal” is a slightly subjective term. However, there exist qualitatively assessable developmental markers that psychologists expect to see during a certain point of development. Therefore, for any certain age, the psychologists could rate whether or not the children are developing at a normal rate, an above average rate, or a below average rate. With this system, at every monthly appointment, each child would be given a rating of negative one, zero, or positive one, to correlate with below average, normal, and above average development, respectively.
Though we believe the study outlined above to be ideal to study the myth of the Mozart Effect, there are some drawbacks that must be addressed. First is that, while each mother would be instructed to play a certain amount of classical music for their child, it cannot be assumed that the amount of music played in the household outside of assigned listening periods is the same for each subject; families vary in their habits. Hopefully, though, the sample size is large enough that the differences due to difference in habits may be negligible. Additionally, we realize that there are some limitations to the scale of measurement we have outlined. It could certainly be argued that children who develop at a different pace than others may very well catch up at a later date and have comparable success in life. However, for the purposes of our study, we believe it is sufficient to rate the children by the same scale once a month, as a child in one group is equally as likely to have some predisposition to developmental complications as a child in another group.
With an analysis of this data that has been collected over a long period of time, the Mozart Effect could empirically be proven or disproven based on a calculation for average developmental normalcy of each group. In order to visually represent any trends existing, a graph could be constructed to show, over time, what percentage of children from groups A, B, and C, were assessed to be developing slowly, normally, or quickly for their age group. Based on evidence we have gathered, it is our prediction that there will be no significant difference in developmental rates of any of the three groups. Despite our prediction, though, a study conducted as we have outlined would be able to assess in an unbiased way any effect that classical music listening has on brain development.
Relationship to Biology 141
The investigation of the Mozart effect might seem like a far removed topic from the concepts taught in Biology 141, but definite connections can be made. The neurological nature of the studies supporting and opposing the Mozart effect relates to the nervous system lectures in class. For example, the Hubel and Wiesel study involves neural pathways from the retinas of the eyes to the occipital lobe of the brain (6). The neurons in this pathway perform cell to cell signaling through electrical impulses traveling from neuron to neuron. These changes in membrane potentials are called action potentials, and they function in communication between neurons. When sensory deprivation occurs, the connections between neurons in these pathways that are necessary to have successful signaling do not form properly. These can be seen in the atrophy and loss of function of the geniculate cells in the sensory deprived kittens in the Hubel and Wiesel study (6).
Another recurring component discussed in our biology class was the importance of various experiments in biological history. For instance, the Hershey-Chase experiment, which determined