Monday, December 1, 2008

Evidence of beat perception via purely tactile stimulation

Brochard, R., Touzalin, P., Despres, O., Dufour, A. (2008) Evidence of beat perception via purely tactile stimulation. Brain Research 1223, 59-64.

By Richard Burrows

Human beings have an innate ability to tap their feet or move their bodies in time to music. This universal behaviour is regarded as the processing of meter. It is unique to the human species, although some animals can produce regular movements. From a perception stand point, meter is experienced in strong and weak beats according to an underlying regular pulse. “More precisely, certain time positions within a metric musical sequence seem to be accented at regular time intervals.” Binary is felt with an accent on every other bear, whereas ternary is felt with an accent on every third beat. “The cerebral response to perceptual changes, occurring on stronger beats, is greater than that to weaker metric positions.”
A recent report from Dr. A. Patel in 2005 presented evidence that showed the inability for humans to detect meter from a visual stimulus. It was again confirmed in Philips-Silver and Trainor’s 2007 research. The same participants had no trouble synchronizing with an auditory stimulus. These findings indicate a relationship between auditory and sensorimotor systems.
Brochard et al questioned whether the process is limited to auditory systems or if the participants could ‘feel’ the bear. The experiment has participants tap their right index finger as regularly as possible in synchrony with strong metric patterns or with weak metric patterns. Their research investigated the potential existence of meter within the somesthetic domain. They found that participants were able to identify sequences in both auditory and tactile modalities. It was found in previous studies that musicians were found to have a more sensitive ear for meter hierarchies, and that nonmusicians process time more sequentially.
“It is still unclear whether meter is a cognitive trait exclusively found in humans. The processing of metric information may be based on widespread synchronization mechanisms shared with non-human species. Consequently, the absence in humans, in the visual domain, of such general capacity of synchronization on multiple hierarchies remains to be explained.”

This experiment is a model for the 5 pillars of research. The constructs were well defined, the design was flawless, the conduct had clear intent with no modifications, the analysis was rigorous, and the interpretation was carefully contrived. Overall, it was a very thorough report.

Research such as this, take my understanding of percussion pedagogy to a whole new level. The ability to pinpoint universal rhythm behaviours is a phenomenon. I am particularly intrigued with this notion of a relationship to auditory and sensorimotor systems. It makes sense when compared to dance, but I am more interested in the effects on hand and arm movement. I am very interested to know the correlation of musicians to nonmusicians and their rhythm perceptions. Is it possible that musician’s sensitivity to meter hierarchy effects other forms of brain function?

No comments: