The neuroanatomical correlates of training-related perceptuo-reflex uncoupling in dancers.
Bottom Line: Adaptation to repeated whole-body rotations, for example, ballet training, is known to reduce vestibular responses.Voxel-based morphometry showed a selective gray matter (GM) reduction in dancers' vestibular cerebellum correlating with ballet experience.Dancers' vestibular cerebellar GM density reduction was related to shorter perceptual responses (i.e. positively correlated) but longer VOR duration (negatively correlated).
Affiliation: Neuro-Otology Unit, Division of Brain Sciences, Imperial College London, London W6 8RP, UK.Show MeSH
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Mentions: Ocular motor and perceptual responses were obtained from pre- and postchair rotations. There were no significant differences between leftward and rightward accelerations, and so they were combined (P > 0.05, F = 1.32, df = 1, factor: Direction of rotation, repeated-measures analysis of variance). Ocular motor TCs ranged from 9.52 to 15.8 s in dancers (mean = 11.7 s, SD = 1.78) and from 11.6 to 18.8 s in controls (mean = 14.9 s, SD = 1.87). Perceptual TCs ranged from 3.1 to 11 s in dancers (mean = 7.24 s, SD = 2.17) and from 5 to 14.5 s in controls (mean = 8.89, SD = 2.68). Dancers had significantly shorter ocular motor (t = −5.83, P < 0.001) and perceptual TC (t = −2.36, P < 0.05) than controls (Fig. 2A). Ocular motor and perceptual TCs were significantly correlated for controls (Fig. 2B; r = 0.46, P < 0.05) but not for dancers (Fig. 2B; r = 0.11, P > 0.05), demonstrating that, at the behavioral level, the normal association between reflex (VOR) and perception (Okada et al. 1999) seen in controls is lost in dancers. The gain in the VOR, calculated as eye velocity divided by chair velocity (90°/s), was not significantly different between the 2 groups (P > 0.05, t-test), with a mean gain of 0.51 (SD = 0.17) for dancers and 0.55 (SD = 0.13) for controls.Figure 2.
Affiliation: Neuro-Otology Unit, Division of Brain Sciences, Imperial College London, London W6 8RP, UK.