Wednesday, November 28, 2012

Practice Makes Perfect: Musical Training has Long-term Impact on Neural Responses

This article appeared in The Tiger on February 17th, 2012 and in the Spring 2012 edition of Tigra Scientifica for BioSc 494: Popular Science Journalism. 


While many people have heard of the pseudoscientific “Mozart effect” on learning, what if actually learning to play music has an even greater, biological benefit? Many musicians start learning their instrument from an early age and continue playing for years to come, spending many hours practicing and playing. As people age, neural responses to aural stimulation slows down, and may lead to issues in communication skills. In January, a study by Dr. Parbery-Clarck, Dr. Nina Kraus and, others published in  Neurobiology of Aging shows that musical training may alleviate age-related delays in response to audio stimuli.
            Why might musical training play an important role later in neural response speed?  Musical training requires a musician to learn to recognize differences in pitch, timbre, and timing— how high or low a sound is, the ‘voice’ of a sound (think how a gravelly old man sounds different compared to a young girl’s soprano), and chronological placement respectively. Dr. Kraus noted in a previous paper that these components are also used to recognize speech. Pitch and placement are needed to understand what people say, particularly in more tonal languages, and timbre helps us distinguish different voices from each other.  Music has also been linked to the adaptability of the brain to learn new tasks and has already been used in speech and motor therapy for stroke victims. Observing how fast a brain responds to sounds may shed further light on how musical training affects auditory responses.
This study looked at nearly 100 participants. They were divided into four categories: older nonmusicians, younger nonmusicians, older musicians, and younger musicians. “Younger” people were 18 to 23 years old, and “Older” people were 43 to 65 years old. Musicians were defined as individuals who began their musical training before the age of nine and continued to play at least three times weekly throughout their lifetimes.  The research team played the speech syllable “da” (chosen for its mix of consonant and vowel sounds) periodically through headphones for participants during a silent captioned film of the patients’ choice. The research team then measured brain responses via electrodes, observing how soon the subcortex responded after the syllable was played in microseconds. 
The researchers found that older participants had slower responses to speech syllables than younger participants. However, the older nonmusicians had significantly later responses than young nonmusicians, while the disparity between older and younger musicians’ responses were narrower. As the speech syllable transitioned from the consonant ‘d’ noise to the vowel ‘a’ sound, older musicians actually had similar response times to younger nonmusicians. The research team concluded that aging negatively affects the processing of noise, especially consonant sounds, but also that musical training reduces those effects.
While these findings are preliminary, previous studies from Dr. Kraus’s laboratory show that musical training is also linked to reduced hearing and memory loss. The research team believes their findings should encourage future investigation into training for keeping neural resilience, the capacity for learning, intact over a lifetime. Dr. Kraus also noted that the study doesn’t necessarily show that musicians have a neural timing advantage to every neural response to sound, but "instead, this study showed that musical experience selectively affected the timing of sound elements that are important in distinguishing one consonant from another." For now, musicians take notice— if you spend more time in the practice room, you might stay sharp in your later years. 
Neurobiology of Aging, Available online 9 January 2012. “Musical experience offsets age-related delays in neural timing” Alexandra Parbery-Clark, Samira Anderson, Emily Hittner, Nina Kraus http://www.sciencedirect.com/science/article/pii/S0197458011005471

 

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