Inside Science
Music Training and the Brain
Professional musicians put extraordinary effort into training on their instrument. By the age of 21 it is estimated that they have played for 10,000 hours. But until recently, it was unclear what effect their experience had on the brain and behavior.
Neuroscientists are studying musicians to assess how performing and practicing music alter psychophysics, cognition, and synaptic physiology — in a clear example of experience-dependent plasticity. The researchers are looking at how musical training influences the processing and perception of sound and examining the effect of music education on brain development. Recent research indicates that musicians excel in areas other than musical ability. For example, they outclass most in processing speech and emotionally expressive sounds.
At Neuroscience 2009, several neuroscientists reported their latest research findings about music training and the brain in a press conference moderated by Mark Tramo of Harvard Medical School. The findings indicate that musicians also perform better than nonmusicians on tasks of auditory attention and on receiving and processing auditory information in challenging listening environments.
Training and Experience Influence Hearing
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The auditory brainstem response to speech in quiet and in background noise by musicians (A,C) and nonmusicians (B,D). Musicians demonstrated a greater degree of similarity between their responses in quiet and noise, suggesting their responses are less degraded by the addition of background noise, unlike nonmusicians. The musicians are plotted in black and the nonmusicians in gray. Credit: Courtesy, with permission: Parbery-Clark A, Skoe E, Kraus K (2009) The Journal of Neuroscience 29(45): 14100-14107.
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Lifetime experience affects the processing and perception of sound even following hearing loss, according to research presented by Markus Engelmann, a researcher at Friedrich Schiller University of Jena in Jena, Germany. Engelmann and his colleagues found that musicians suffering from hearing loss could detect whether chords were out of tune, even when the tones were in the range of sounds they could no longer hear well. Although the musicians performed well on the task, factory workers with similar hearing deficits did not. EEG recordings showed that the musicians’ brains registered whether a chord was in or out of tune, even if the musicians did not consciously perceive the sound.
The findings suggest that the typical sounds associated with a profession build a set of auditory skills that seem to sharpen the ability to extract and identify related sounds. Both musicians and factory workers show high rates of occupational hearing loss after being exposed to loud noise over the course of their careers. Engelmann suggests that while the musicians were better able to identify “failed” musical tones despite their hearing loss, the factory workers may be similarly skilled at identifying sounds indicating machine failure.
Musical Experience Strengthens Cognitive Function
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The ability of musicians to distinguish speech in background noise is better than nonmusicians. A musician’s perception of speech in noise improves as the number of years of musical training increases. Credit: Modified, with permission: Parbery-Clark A, Skoe E, Lam C, Kraus N (2009) Musician Enhancement for Speech-In-Noise. Ear & Hearing 30(6): 653-661.
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Musical experience also appears to strengthen cognitive function related to auditory attention and memory, according to Dana Strait, a graduate student working with Nina Kraus and Richard Ashley at Northwestern University. Strait and her colleagues found people with extensive music training outperformed those with little to no musical training on tests of auditory attention, frequency discrimination, and backward masking — the ability to distinguish one sound from another that comes after it. The researchers controlled for differences in IQ and hearing, and there was little difference between the two groups on tasks that tested visual attention. The findings suggest long-term musical training fine-tunes the neural mechanisms that lead to enhanced performance of auditory tasks.
This study joins a growing body of research supporting the idea that musical training could benefit children who have difficulty with auditory processing and related language and literacy skills. These children struggle to attend to particular brief sequential sounds, which interferes with their ability to hear certain syllables in spoken language. Strengthening cognitive and perceptual functions through auditory training (i.e., musically) could help them overcome their disability. Researchers are just beginning to examine the underlying processes that bolster musicians’ cognitive and perceptual enhancements — possibly a top-down modulation of cochlear and brainstem function mediated by the corticofugal pathway, according to Strait.
Musicians Are Better Listeners at Cocktail Parties
The ability to extract spoken words from background noise can be challenging for many people, especially for older adults, children with language-based learning problems, and people who are hearing impaired. Musicians, though, seem to have less difficulty, according to research presented by Kraus.
Musicians need to listen specifically for the sounds of their own instruments among many others. Does this enhanced ability to distinguish sound translate to non-musical skills? In their research, Kraus and colleagues treated speech-in-noise as a homolog for segregating musical sounds. They compared behavioral performance and evoked auditory brainstem responses in musicians and non-musicians listening to speech sounds in two settings: quiet and noisy.
The musicians were better able to identify speech presented against background noise and exhibited stronger speech-evoked auditory brainstem responses. Further, the musicians displayed earlier response onset timing and greater phase-locking to the temporal waveform and stimulus harmonics. In other words, background noise had a smaller negative impact on auditory processing in musicians than in non-musicians.
Musicians with more years of musical experience were better able to detect speech in noise than their younger colleagues, highlighting the continued plasticity of the auditory system and suggesting that with practice, distinguishing sounds becomes easier for the brain. If musical training could enhance the ability to hear spoken words against a background of everyday noise, this could ultimately lead to a therapy for people who face the challenge or for those with learning or communication disorders.
This new research on music and learning, which represents a small slice of a growing research field, shows that rigorous and long-term training on auditory tasks can strengthen cognitive and perceptual abilities related to the auditory domain in a clear example of experience-dependent plasticity. Listening alone does not appear to do the trick — actual performance appears to be necessary to achieve these benefits.
These findings also add to a growing body of data from a variety of laboratories suggesting that musical training could help people, especially children with developmental dyslexia who often experience noise-exclusion deficits. Interestingly these children can demonstrate neural deficits in the subcortical processes that are enhanced in musicians. An estimated 10 percent of children in developed countries wrestle with language and learning deficits. Ongoing longitudinal studies are also currently helping to determine in a rigorous fashion whether music education has beneficial effects on brain and behavior for children of all abilities.
To view the video of the press conference and related slides, go to www.sfn.org/amhighlights.