The ability to move rhythmically to a musical beat is universal within all human cultures. While tapping your foot to the beat of music may seem effortless, the mechanism that actually allows us to do this remains a mystery. Dr. John Iversen at the Neuroscience Institute in San Diego is working to uncover the brain mechanisms that enable us to hear the beat, and thus allow us to dance, sing and clap in time to music. Such knowledge could help people with movement disorders such as Parkinson's disease.
To understand beat perception better, Dr. Iversen is working together with Dr. Aniruddh Patel to measure the response of peoples' brains while they listen to rhythms. In fact, hearing the beat in music is an active, creative process -- the beat isn't actually in the music, but is created by our brains. It is that creative process that researchers are trying to understand. Listeners were asked to hear a simple rhythm (two notes followed by a rest: a "swing" pattern) with the beat in different places. Hearing the beat on the first note yields a pattern that sounds like DA-dum DA-dum..., while hearing the beat on the second makes exactly the same rhythm sound different, like da-DUM da-DUM. Dr. Iversen found that how one hears the beat causes a large change in the brain's responses to sound. The changes were in a range of brain responses called the beta band (20 to 30 oscillations per second), which is known from past studies to be associated with activity in the brain's motor centers. This suggests that even the simple, seemingly passive act of listening to music involves motor processes, even the absence of overt movement.
When the ability to move is impaired, such as in Parkinson's disease, the effect can be catastrophic, often making basic rhythmic motor activities like walking impossible. However, researchers believe that the deep connection between music and movement can be used to assist those w
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| Contact: Jason Bardi jbardi@aip.org 301-209-3091 American Institute of Physics Source:Eurekalert |