Mammalian vestibular hair cell regeneration

musicians and musicians did not differ in body length (P> 0.05). 19. No formal test for perfect pitch was applied. Subjects were asked if they would be able to sing any tone without a reference tone and if they could name any tone that was given to them without a reference tone. In those musicians who described themselves as having perfect pitch (n = 11), this information was confirmed by review of their music school examination records for pitch discrimination task performance. 20. In distinguishing between musicians with or without perfect pitch, we were guided by a study of D. Sergeant [J. Res. Mus. Educ. 17, 135 (1969)] investigating the possession of perfect pitch in a large sample of professional musicians. In this study almost all musicians who began training before the age of seven had perfect pitch, but almost none of those beginning after the age of 1 1. Similar results were also found by others suggesting that early exposure and disposition may underly this ability [A. Bachem, J. Acoust. Soc. Am. 27, 751 (1955); C. L. Krumhansl, Annu. Rev. Psychol. 42, 277 (1991); M. Klein, M. G. H. Coles, E. Donchin, Science 223, 1306 (1984)]. 21. For statistical analysis, WPT values (16) were subjected to a one-way analysis of variance (ANOVA) with three levels (musicians with or without perfect pitch, and controls). In this ANOVA two planned orthogonal (linear) contrasts were computed, comparing musicians versus controls and musicians with perfect pitch versus musicians without [R. E. Kirk, Experimental Design: Procedures for the Behavioral Sciences (Wadsworth, Belmont, CA, 1968), pp. 69-98]. The results were as follows: orthogonal contrast for musicians versus controls: [F (1 ,57) = 5.12, P = 0.028]; orthogonal contrast for musicians with perfect pitch versus musicians without: [F (1 ,57) = 16.18, P < 0.001]. Prior to the ANOVA, a Bartlett-Box-test for homogeneity of variances of WPT had revealed no deviation from the homogeneity assumption {[F (2,4840) = 1.25, P = 0.32]). 22. K. Kleist, Sensorische Aphasien und Amusien auf myeloarchitektonischer Grundlage (Thieme Verlag, Stuttgart, 1959), pp. 32-43. Similar cases of musicians with or without musical impairment lacked precise pathoanatomical verification (2) [A. R. Luria, L. S. Tsvetkova, D. S. Futer, J. Neurol. Sci. 2, 288 (1965); T. Alajouanine, Brain 71, 229 (1948)]. 23. J. L. Ringo, R. W. Doty, S. Demeter, P. Y. Simard, Cereb. Cortex 4, 331 (1994). On the basis of estimates of interhemispheric conduction times and on a neuronal network model, the authors hypothesized that "finely detailed, time-critical neuronal computations . would be performed more quickly via shorter and faster intrahemispheric circuits," and more generally that "unilateral clustering of related memories and skills would manifest itself as hemispheric specialization. " 24. S. F. Witelson and W. Pallie, Brain 96, 641 (1973); J. A. Wada, R. Clarke, A. Hamm, Arch. Neurol. 32, 239 (1975); J. G. Chi, E. C. Dooling, F. H. Gilles, ibid. 34, 346 (1977). 25. W. Welker, in Cerebral Cortex, E. G. Jones and A. Peters, Eds. (Plenum, New York, 1990), vol. 8B, pp. 3-136. 26. P. I. Yakovlev and A. -R. Lecours, in Regional Development of the Brain in Early Life, A. Minkowski, Ed. (Blackwell, Oxford, 1967), pp. 3-70. 27. Supported by the Deutsche Forschungsgemeinschaft (SFB 194) and the Hermann und Lilly Schilling Stiftung (H.S.). We thank U. Mddder (Institute for Diagnostic Radiology, Heinrich-Heine-Universitat DOsseldorf) for use of the magnetic resonance imaging facility.