First Example Summary:

Berns, G., Capra, C.M., Moore, S, & Noussair, C. (2010) Neural mechanisms in the influence of popularity on adolescent ratings of music. Neuroimage, 49, 2687-2696.

This paper explores the impact of knowing other’s preferences for music on the ratings of liking for unfamiliar music and corresponding brain activity during listening and rating.  Twenty-seven adolescents between the ages of 13 and 17 were asked to listen to 60 fifteen second selections from three genres of music selected from MySpace.com that were consistent with the participant’s genre preference but with very few public likes (consequently likely to be unfamiliar).  After listening to these selections they listened again and rerated liking.  For forty of the sixty listening segments in the second block, the liking ratings of others were made available one at time just before the segment was presented.  The dependent variables included time taken to rate liking the second time through the listening segments, whether or not and the extent to which ratings changed from the first listening experience to the second, and brain activation captured via fMRI.  Participant’s second ratings of liking were faster and more likely to change when they were given information about other’s preferences.  Participants whose ratings changed most were most likely to show activation in the caudate nucleus, suggesting aversive experience when seeing that their first session ratings were in disagreement with ratings of a general audience.  Participants whose ratings changed most were also most likely to show reduced activation in the temporal gyrus.  This is interpreted by the authors to mean less listening engagement.  Younger adolescents showed this effects more strongly than older adolescents.  The observation that finding one’s responses out of line with a general audience activates brain regions that may motivate changes in behavior is very interesting from the perspective of a social psychologist interested in understanding the impact of groups on individuals.  That this effect is age dependent is also interesting from a developmental perspective.  In this case the ratings of others responses to the music were genuine and not artificially assigned.  This strikes me as both a strength and a weakness.  The strength is that it allows us to see how groups naturally move toward a consensus.  The weakness is that it may be that those who have changed the most are those whose initial ratings are least like the norm.  After all, these participants are those who will experience the most discrepancy between their ratings and those of the norm group.  How else do these participants differ?  It would be interesting to replicate this study with ratings from others that were not only discrepant from the participant’s rating but clearly different, perhaps wrong from the listener’s perspective.  The student might have been more compelling if there had been a way to demonstrate brain activation to independent stimuli producing social discomfort or listening pleasure in these participants to compare to their responses during the music listening task.   The author’s ability to provide evidence that the change in music ratings found in the second rating is more closely related to a response to discrepancy from others than to a joy at having others agree with you makes this a very interesting paper.

Second Example Summary:

Hauser, F. & McNitt-Gray, J. (1992) EMG patterns in embouchure muscles of trumpet players with asymmetrical mouthpiece placement. Medical Problems of Performing Artists, 8, 96-102.

The purpose of this article was to ask if professional trumpet players who played the trumpet by placing the mouthpiece off center on their lips (embouchure) differed in the pattern of muscles used to produce a tone from other professionals who used the mouthpiece placement recommended by trumpet instructors.  Additionally, the paper asks whether this is equally true when players are performing a musical task, e.g., an excerpt from concerto as it is when they are simply playing a musical exercise, e.g. a musical scale. The dependent variable observed in all performers was the amount of muscle activation found in four groups of muscles, the left and right zygomatic major and the left and right depressor anguli oris.  Activation was measured via surface emg and sampled at 2000 samples/second.  The subjects were all full-time professional trumpet players.  Five habitually played with symmetric mouthpiece placement and three habitually played with asymmetrical placement.  Sound was also recorded so that onset of muscle activity could be associated with onset of tone.  Each player was asked to perform each of four musical exercises: (1) a series of three half notes played in each of three octaves starting with middle c, moving up an octave, and then moving up another octave.  In this same exercise, they again played sequences of three notes at the same pitches but played quarter notes rather than half-notes; (2) a series of open tone notes on the C arppegio in both half and quarter notes; (3) an excerpt from the Verdi Requiem; and (4) an excerpt from Tchaikovsky’s Fourth Symphony.  The results were assessed by looking at each individual’s pattern of muscle activity and comparing the shape of the burst patterns in muscle activity.  Although there were individual differences in the extent of muscle activity, the pattern of which muscles were engaged during tone performance and their onset and offset times in relation to the onset and offset of tones was similar regardless of whether the mouthpiece was positioned symmetrically or asymmetrically.  Patterns were also similar when performers played musical selections or individual notes found in the first two exercises.

This paper demonstrates the usefulness of surface measurement of muscle activity during performance and addresses a pedagogical question about the importance of insisting that trumpet performers adhere to the same strategy for generating tones.  The method of analysis doesn’t allow a quantitative statistical assessment of differences and appears largely to affirm the null hypothesis, which is ordinarily a bad idea.  It is difficult to assess the generalizability of the results without knowing how representative these eight performers are of professional trumpeters in general.  It would also be helpful to have a quantitative assessment of the degree of asymmetry and perhaps other measures of performance success than muscle activity.  Overall, I find the article raises interesting questions and provides useful guidelines for the use of surface emg in research on musical performance.