Saturday, December 6, 2008

Virginia Penhume: The Neural Basis of Auditory-Motor Interactions: Auditory Control-Motor Perception

McMaster institute for Music and the Mind (MIMM) Workshop, November 29, 2008
Musical Connections in the Brain: Language, Dance and the visual Arts

Sharon Dutton

The first speaker of the workshop, Dr. Virginia Penhume, is one of the core members at the McMaster Institute for Music and the Mind. Her primary research interests are in the development of auditory perception, including basic sound perception, and the acquisition of music and language. The topic of her presentation was “The Neural Basis of Auditory-Motor Interactions: Auditory Control—Motor Perception”. Although the research in this field is in its infancy, Dr. Penhume identified four characteristics of the neurological motor response to music:

> it is spontaneous
> it is selective
> it differentiates between metres
> the neural mechanisms that respond are separable (from their brain sites).

She spoke first on the human propensity to “move to the beat”, and defined rhythm as an emergent percept, ambiguous, with no single feature, being created entirely in the mind. She is interested in exploring how the mind forms this percept, and identified three descriptive qualifiers about rhythm:

> Accent
> Beat
> Metre

To answer the question, “How does accent / meter impact motor response?” she created a set of tests wherein musicians and non-musicians would undergo brain scans while hearing a rhythm, and immediately thereafter, while hearing and simultaneously tapping the rhythm. Several progressively more difficult rhythms were used as samples. Using functional magnetic resonance imaging (fMRI), she was able to measure, and then examine brain activity during these tasks; she also measured the amount of deviation in the tapped rhythm from the sample.

Dr. Penhume found (not surprisingly), that musicians were more accurate than non-musicians in their reproductions of the rhythmic samples. Musicians demonstrated less brain activity than non-musicians overall, and their brain activation patterns employed more “top down” function, purportedly because they have much more experience with this task, and have to work less to perform the task. For musicians and non-musicians, she found that the dorsal pre motor cortex (dPMC) is activated by abstract information from sensory cues. Auditory-motor coupling was apparent in other parts of the brain as well, but the PMC was critical for linking sound and action. The pre-motor cortex is critical for linking sound and actions. She referred to studies (Trainor 2005, Elbert 1995) that addressed early as opposed to late musical training; findings are that there is more brain development when early training occurs, (again, not surprisingly). However, in her study, Penhume found that late trained musicians out-performed auditory rhythmic reproduction tasks in deviation scores, while rhythmic perception was equal for late and early trained musicians. Early trained musicians demonstrate better sensorimotor integration and prediction. She noted that musicians are alert to visual cues, and closed with the suggestion that children who are better imitators might make better musicians.

Dalcroze teachers are excited about the fact that neuroscientists have discovered a connection between motor and auditory functions in the brain through fMRI testing. Emiles Jaques-Dalcroze discovered this link 100 years ago through insightful observation, and used his discovery to develop, through trial and error, an approach to music education in and through the body, using movement to musically prepare the student for formal music study. It is cause to celebrate, because this field of neuroscience, hypothesizing about and exploring the musical connection between mind and body. Headline: Listening to music induces motor response! It is exciting because when this field develops, when the questions that are generated by these preliminary findings are answered, then the Dalcroze teachers, (and the Orff teachers, and the Early Childhood Music Educators) will in turn, learn from the neuroscientists, and most of those answers will inform music educators of any level.

Of course any layperson would acknowledge a link between music and movement, can recognize that all music requires movement – there can be no sound without vibration – and all musicians have to move something to create sound (music), with more or less skill, insight, and expression. But, this is not the same thing as what Dr. Penhume addresses. It would amount to putting the cart before the horse, so to speak. Dr. Penhume has discovered that by listening to music, the motor function in the brain is consequently activated. She and other neuroscientists have discovered a propensity for the motor functions of the brain to respond to hearing a beat, and fMRI testing allows us to witness this connection.

This is just the beginning -- a very primal beginning of -- an emerging field. The beat – the most essential of all musical elements, if heard alone, is not music. Metre is not music, timing is not music, and accurate reproduction of rhythm patterns is not music. I wonder if brain scans will one day be able to observe the “great musician” in the brain. Is he/she/it even in the brain? While we can measure rhythmic reproduction, pitch reproduction, and attentive listening, there is still the mysterious spark of life that makes music Music. I look forward to all that neuroscience will teach music educators, but my sense is that the “great musician” will dodge fMRI testing, existing, as it will, in the infinitesimal spontaneity of humanity’s most expressive self, wherever that may be.

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