Effect of Music by Mozart on Energy Expenditure in Growing Preterm Infants

The ‘U2 effect’?

Dear Editor,

In the January issue of Pedriatrics, Lubetzky et al. [1] report a pilot study demonstrating that listening to music by Mozart for less than half an hour reduces the resting energy expenditure (REE) of preterm (but otherwise healthy) babies. In their study, a prospective clinical trial with crossover, two groups of babies (Mozart Music, n=5; No Music, n=13) were monitored for a half-hour interval on each of two successive days. On the first day, the smaller group was observed with music present and the larger group with music absent; on the second day, the larger group was observed with music present and the smaller with music absent.

The REE results for the two groups were averaged over the first, second, and third 10-minute periods within each half-hour session. Table 2, which apparently summarises the results of the first day’s testing only shows that in the Music Present group, all three means, including the baseline mean for the first ten minutes, are lower than the corresponding values for the Music Absent group. It would appear, therefore, that the randomisation process failed to produce comparable samples. (The mean for the smaller sample was based upon only 5 observations.) In both groups, the mean REEs for the second 10-minute period are higher than the means for the first period. In support of their case for an effect of the presence of music, the authors observe that, while the difference between the group means for the first 10-minute period is small and statistically insignificant, the differences between the group means are larger and statistically significant for the second and third periods.

On this basis, the authors claim to have discovered yet another ‘Mozart effect’, adding to a long (and growing) list of beneficial effects (mental and physical) supposedly resulting from listening to the music of this particular composer [2]. The evidence for these reported effects, however, often turns out to be highly questionable [3].

The authors’ case for a ‘Mozart effect’ is less than compelling when viewed in the light of their methodology and their statistical analysis. In their study, the assignment of the babies to the two groups by using a random number table, produced markedly disparate numbers in the two groups of babies: 5 in the Music First group; 13 in the No Music First group. This is unfortunate: had the babies been assigned to the groups on the basis of tossing a coin, the probability of such a discrepancy would have been less than 10%. Arguably, assigning the babies to the groups by simple alternation would have produced more comparable samples; and for the purposes of this study, comparability of the samples is of paramount importance.

In Table 2, there is no mention of the grouping variable: the headings in the table indicate the Music Present and Music Absent conditions only. From the text, however, it would seem that Table 2 summarises the data from the first testing session only: ‘REE was similar during the first 10-minute period of both randomization groups’(e26). Later in the paper, there is a brief reference to the data from the second testing session: ‘Based upon the fact that infants who had been first randomly assigned to the music period and were studied the following day for 30 minutes of no music had at baseline an REE very similar to that of the first 10 minutes of the music period probably means that the effect of music that we observed is not long lasting and is no longer present 24 hours after music is stopped’(e27).

The authors’ reporting of their statistical analysis raises additional concerns: ‘Comparison of energy expended values between groups was performed by using paired t-test [sic]’ (e27). Since there would appear to be no basis for pairing the markedly unequal samples of scores summarised in Table 2, the provenance of the p-values given in the table is unclear, especially since the degrees of freedom of the test statistics are omitted.

In view of the prior heterogeneity of the samples, it would arguably have been better to use difference scores to compare the REEs of the babies in each group after ten minutes with their REEs over the second and final ten minutes of the testing period. There, at least, the babies would been serving as their own controls and we could have compared the means of the difference scores in the two groups.

The attribution of an effect to the music of any particular composer requires the inclusion in the study of music by other composers for comparison. This is acknowledged implicitly by the authors when, in their discussion, they dismiss the failure of another study [4] to find an effect of music on the REE of obese adults partly on the grounds that they used music by Satie, Bach, Bartok, Stravinsky, and Henze, but not Mozart. The same objection applies to their own study, in which music by Mozart alone was used. From the foregoing considerations, however, their claim to have demonstrated any musical effect at all, let alone a Mozart-specific one, remains unproven. We have found the reported performance effects of music to be, to say the least, ephemeral: rarely if ever can they be replicated [4]: whether the music is Mozart, minimalist music or U2, it would appear to have little or no enhancing effect. A fortiori, claims that the presence of music reduces resting energy expenditure or has other physiological effects should be viewed with caution.

In general, the scientific community has been too ready to accept the existence of ‘Mozart effects’ as an established fact. In their introduction, for example, Lubetsky and his co-authors cite positive findings only, omitting mention of the many studies that have failed to replicate previously reported effects [e.g, 5-7]. A comprehensive meta- analysis, moreover, provides little or no evidence for ‘Mozart effects’ of any kind [8].

Music enriches our lives in many ways; but whether, in addition, it can affect physiological variables such as REE remains to be seen. We are sceptical; and we wish to share our scepticism with readers of Pediatrics.

Colin Gray School of Psychology, University of Aberdeen, UK Sergio Della Sala Human Cognitive Neuroscience, University of Edinburgh, UK

References

1. Lubetzky R, Mimouni FB, Dollberg S, et al. Effect of Music by Mozart on Energy Expenditure in Growing Preterm Infants. Pediatrics 2010;125: e24-e28

2. Campbell D. The Mozart effect: Tapping the power of music to heal the body, strengthen the mind, and unlock the creative spirit. London: Hodder & Stoughton, 1997

3. Gray C. & Della Sala S. The Mozart effect: it’s time to face the music! In Della Sala S. (Ed.) Tall Tales About the Mind and Brain. New York: Oxford University Press, 2007, pp. 148-157

4. Carlsson E, Helgegren H, Slinde F. Resting energy expenditure is not influenced by classical music. J Negat Results Biomed. 2005; 4-6

5. Newman J, Rosenbach JH, Burns KL et al. An experimental test of the "Mozart effect": Does listening to his music improve spatial ability? Percept. Mot. Skills 1995; 81: 1379-1387

6. Stough C, Kerkin B, Bates T et al. Music and Spatial IQ. Personality & Individual Differences 1995; 17: 695

7. Steele KM, Brown JD, Stoecker JA. Failure to confirm the Rauscher and Shaw description of recovery of the Mozart effect. Percept. Mot. Skills 1999; 88: 843-848

8. Chabris CF. Prelude or requiem for the 'Mozart effect'?. Nature 1999; 400: 826-827

Conflict of Interest:

None declared

June 30, 2011

Lewis R. First, MD Editor-in-Chief Pediatrics University of Vermont College of Medicine Given Building S261 89 Beaumont Avenue Burlington, Vermont 05405-0068

Dear Dr. First:

Re: 'Disparities in Child Access to Emergency Care for Acute Oral Injury' ("Pediatrics," June 2011, Volume 127/ Issue 6) tells or, more accurately, retells a disturbing story. No child or adult should suffer with untreated disease or injury. The authors' conclusion, that the study has "implications for developing policies that improve access to oral health Care," is a classic understatement. But what are those implications?

That such an overwhelming majority of the dentists contacted would refuse to see a child under those circumstances just doesn't reflect my experience. As a dentist who has practiced in Illinois for nearly 30 years, I know firsthand the frustrations of dealing with the state's Medicaid program. But that does not deter many of us from treating these patients. I started a special clinic in McHenry County in 1996, which is now in its15th year of uninterrupted service to children and adults who rely on Medicaid and could not otherwise afford care.

Bisgaier et al mistakenly assumed that non-enrolled dentists could actually bill Medicaid for emergency services. This is not correct and deflates one of the main points of the entire study. Forty-four of the 85 dental practices called could not provide care and obtain any reimbursement because they were not enrolled as Medicaid providers.

The authors' apparently were misled regarding Illinois Medicaid fee schedule, which they stated reimburses at 53 percent of customary fees. The actual reimbursement rate for the 10 most common dental procedures in Illinois is 46 percent. For restorative and specialty care, the rate is 15 to 26 percent.

Overhead costs for the average dental practice run from 60 to 70 percent. Even at the high end, Medicaid reimbursement doesn't cover the cost of delivering care. Add to that the administrative costs of filing claims and you begin to see how difficult it can be for many dentists to participate in the program. As one colleague put it, "I'm paying for the privilege of treating these patients." As a result, I and many other dentists in the state routinely treat Medicaid-eligible patients for free, rather than deal with the inadequate reimbursement and cumbersome paperwork.

The report left me asking more questions than it answered. How many of the more than 2,600 registered Medicaid providers were already accepting more patients than they can afford to treat under the Illinois fee schedule? How many of the non-Medicaid dentists are former Medicaid dentists who became so frustrated with the system that they stopped participating? What would the appointment rate have been had the call come from a school nurse, community health worker, physician's office, social services agency or the local or state dental society?

Lack of funding is among the greatest barriers to better oral health in America. But funding alone will not "fix" programs like All Kids in Illinois. Patients need help navigating an often complicated bureaucracy and overcoming other barriers. Medicaid programs need to be reformed, so that red tape is not a disincentive to dentists' participation. I wonder what the results would have been had the same study been conducted in Michigan, Tennessee or Alabama, where these changes have reaped dramatic increases in both participation and utilization.

As a profession, dentistry's generosity is abundant. In fact, as a special effort to serve, Illinois dentists provided care to nearly 2,000 patients at a Mission of Mercy (MOM) event just last year. There are plans to improve on those numbers in a similar event which is scheduled for 2012. According to the American Dental Association's best estimate, dentists nationwide provided $2.16 billion in free or discounted care in 2007 alone. The estimate for Illinois that year is $80 million.

I do not mean to defend, across the board, the dentists who were contacted by Pediatrics and would not schedule an appointment for the Medicaid enrolled child. There is simply not enough information to know what occurred during those telephone calls to judge them one way or another. There can be no argument that untreated dental disease in America is a national disgrace. But rather than finger-pointing, it is critical for all parties involved to continue working together toward the day when no one is turned away by a failed system or has to rely on charity to attain the good oral health that everyone deserves.

Sincerely, Joseph F. Hagenbruch, D.M.D. Eighth District Trustee American Dental Association 502 North Hart Boulevard Harvard, Illinois 60033-2445 815-943-5420 Telephone 815-943-5429 Facsimile [email protected]

Conflict of Interest:

None declared