Mozart Effect: The effect of music on premature babies

By Nestor Lopez-Duran PhD

Do you remember the Mozart Effect? In the 1990s a small yet very influential study showed that listening to classical music, and in particular Mozart, improved test performance in college students -thus Mozart must make you smarter! The public reacted and an entire industry was born. Parents rushed to the stores to purchase Mozart CDs so they could play it to their unborn children (hopefully not Mozarts Requiem which, although is one of my favorite works of all time, it is bound to traumatize anyone under 14). Even the State of Georgia passed a law requiring the free distribution of CDs to new mothers! The Governor at the time was widely quoted saying:

As you know, the brain has two lobes. The studies show that music engages both hemispheres of the brain its creativity and emotion engage the right lobe, while rhythm and pitch engage the left. So people who receive musical exposure at a young age develop a bundle of nerves that connects those two halves*

*I should go on, but I must note that the only thing correct in the above quote is that music indeed engages both hemispheres of the brain.

Since then, the effect of Mozart on intelligence was discredited. In fact, a comprehensive meta-analysis (a statistical reviews of previous studies on the topic) concluded that listening to Mozart actually had no effect on intelligence.

Yet, something very positive came out of these studies. Soon after, a series of studies showed that Mozart improves performance in some people because of its calming effects. That is, listening to mozart reduces stress in many people, and for those who are anxious, such reduction in stress would lead to better performance (e.g., whether a test or a sporting event). Other studies also showed that playing Mozart to at risk infants (premature or those with severe medical complications) resulted in better medical outcomes, such as fewer hospitalization days and more rapid weight gain.  Yet, researchers have not been able to identify the actual mechanisms that explain why premature babies react this way to Mozart.

In the last issue of the journal Pediatrics, there was a very small yet fascinating study on the effects of Mozart on premature babies. A team in Tel Avid was interested in examining whether changes in metabolic efficiency could explain the better outcomes observed among premature babies exposed to Mozart. In the study, the authors examined 20 preterm infants with a mean gestational age at birth of 29 weeks (range 26-35) and who were otherwise medically stable. At the time of the study, the infants were at a chronological gestational age of 30 to 37 weeks.  The methodology involved a randomized cross-over design. This means all babies where tested in both conditions during 2 consecutive days at the same time of the day. Some babies listened to Mozart during day 1 and underwent the no music condition during day 2, while other babies experienced the no music condition during day 1 and listened to Mozart during day 2.

The results:

The authors found that within 10 minutes of the start of the music the infants experienced an average of a 10-13% reduction in their Resting Energy Expenditure (REE). REE is often considered a measure of the amount of calories required to function during a specific time period during resting conditions. How could this contribute to our understanding of the Mozart effect on premature babies? If a baby reduces his/her REE, the baby then requires LESS calories to function. Imagine for a second that you require 2000 calories to function during the day. If you eat a 2,000 calorie diet, you would theoretically maintain your weight. Now imagine that you reduce your REE so now you only require 1,500 calories to function, yet you continue to eat the 2,000 calories (I think we call this aging!). What would happen? A similar process may be at play with these infants. It is possible that exposing the infants to Mozart reduces their REE and this results in a higher ratio of consumed calories to calories used, and thus more rapid weight gain and better medical outcomes.

Although this is a very compelling study, the authors warned that more research is necessary with larger samples. Yet, these findings, combined to previous findings showing improved medical outcomes among at-risk infants exposed to music, makes you wonder whether neonatal intensive care units should consider music exposure as standard practice for at risk infants.

The Reference:

Lubetzky, R., Mimouni, F., Dollberg, S., Reifen, R., Ashbel, G., & Mandel, D. (2009). Effect of Music by Mozart on Energy Expenditure in Growing Preterm Infants PEDIATRICS, 125 (1) DOI: 10.1542/peds.2009-0990