Tuesday, December 9, 2008

PItch Perception and Prosody

Language, Music and Brain Plasticity in 8-year-old Children
A presentation by Dr. Mireille Besson
MIMM Workshop: Musical Connections in the Brain: Language, Dance and the Visual Arts
Saturday, November 29, 2008, McMaster University
(NOTE: this presentation was informed by the following study:
Magne, C., Schon, D., Besson, M. Musician Children Detect Pitch Violations in Both Music and Language Better than Nonmusician Children: Behavioural and Electrophysiological Approaches. Journal of Cognitive Neuroscience, 18:2, pp. 199 – 211)
Review and Response by
John Picone
As a high school educator whose career has enjoyed the passions of teaching both English and music, I am fascinated by the relationship between these two phenomena in the brain. Specifically, the role music plays in the way our brains process and produce language.
Pitch discrimination in music increases with training. Pitch is significant in conveying semantic meaning in speaking and listening to a language. It is clear that the exaggerated pitch contours of infant-directed speech appeal to the music part of the brain and assist in the processing of pitch in language as it enhances semantic meaning. It’s a kind of “musical training” at a very young age that sensitizes a person to the prosody of language.
Dr. Besson set out to discover if deliberate musical training would enhance both pitch discrimination in music and language in 8-year-old children. Her participants had no musical training prior to the experiments. The children listened to a familiar melody and were asked to indicate whether the last note was the correct pitch. They heard either the correct pitch (congruous), one that was out of pitch by a fifth of a tone (weakly incongruous) and one that was out of pitch by half a tone (strongly incongruous). The participants also listened to a sentence where the final word was pitched congruously, weakly incongruous (35%) or strongly incongruous (120%). Results were recorded.
Once a base line was established, the children were divided into two groups of ten. One group received musical training while the other was engaged in painting. These classes were for a period of 8 weeks. The children were tested again after this period with the addition of identifying whether the final word of a sentence was pitched appropriately. There were no significant differences in their responses.
The same experiment was then carried out with two new groups, each with 16 eight-year-old children. This time, however, the musical training and painting was for a duration of six months. The same test was administered to determine any changes in pitch perception with respect to both the melody of a musical line or the prosody of the sentence.
The results showed that the children who experienced the six months of musical training clearly outperformed the nonmusicians in both the musical aspect of the test as well as in the language component. The researchers importantly addressed the issue of IQ, referring to findings by Schellenberg (2004) which showed that one year of musical training significantly improved IQ. “In this case, however, one would expect differences between the two groups of children in the three experimental conditions. The present results show that this is not the case: The only significant difference between the two groups was found for the weak incongruity” (p. 204).
The significance of this study is the impact of musical training, specifically pitch perception, on sensitivity to the pitch component of linguistic prosody. This aspect of speech is most importantly aligned with the speaker’s conveyance of emotion and attitude, and the listener’s ability to perceive this. Pitch, of course, is only one aspect of linguistic prosody.
While the results of Besson’s study strongly suggest that there is a common mechanism in the brain for processing pitch in both music and language, one cannot help but wonder what the greater significance of this might be with respect to linguistic communication. Another study (Songs as an aid for Language Acquisition, Besson et al., 2008) suggests that pitch perception is significant in the auditory processing of word boundaries. Research (Deutsch et al., 2004) has also suggested that speakers of tone languages such as Mandarin and Vietnamese rely heavily on pitch perception for lexical meaning.
Besson’s results indicate an enhancement of perception of the prosodic elements of spoken language. Does it follow that the musically trained person is therefore more sensitive to the emotional or attitudinal disposition of the speaker? Pitch is, after all, only one element of prosody.
One characteristic of a child with Aspergers syndrome is the weaker ability to perceive emotion in a social context. Would musical training assist such a child in their perception of emotional laden prosody?

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