The relation between lateralisation, early start of training, and amount of practice in musicians: A contribution to the problem of handedness classification

Abstract

This study investigates the influence of extensive bimanual training in professional musicians on the incidence of handedness in the most basic form of right-handedness (RH) and non-right-handedness (NRH), according to Annett's “right shift theory”. The lateralisation coefficients (LCs) of a total sample of 128 bimanually performing music students were calculated for speed, regularity, and fatigue of tapping by using the speed tapping paradigm. Additionally, the accumulated amount of practice was recorded by means of retrospective interviews. The proportion of designated right-handers (dRH) and non-right-handers (dNRH) in hand performance was identified by binary logistic regression from LCs. A proportion of 30.8% designated NRH in the group of musicians was found, while in the control group of non-musicians (matched for age range) a proportion of 21.7% designated NRH was observed. Incidence of dNRH was higher in string players (35.6%) than in pianists (27.1%). As an effect of the extensive training of the left hand, tapping regularity increased and tapping fatigue decreased among those participants who evidenced an increased amount of accumulated practice time on the instrument. However, speed difference between hands (as indicated by LCs) remained uninfluenced by bimanual training. This finding is in contrast to those of Jäncke, Schlaug, and Steinmetz (1997). Finally, our study provides a more reliable (statistical) classification as an external criterion for future genetic analyses of handedness.

Keywords:

• Music performance
• Handedness classification
• Laterality

Acknowledgements

We would like to thank three reviewers for very helpful comments on an earlier version of this study.

Notes

¹Additionally, we see no alternative to separating the genotypes C and D (C=chance and D=dextral) in the forms of CC, DD, and DC as postulated by McManus (1985) by means of hand performance measurement, because the author did not provide a chance factor for the DD genotype. In contrast, performance data always show a high degree of variability. Furthermore, McManus (2002) assumed that hand preference precedes hand performance and is widely independent of performance, while Annett (2002) took an opposite view.