Vestibular memory-contingent whole-body return: brave exocentered dancers.

A whole-body, self-driven return from passive rotation (90 degrees to 270 degrees ) test was executed by male and female subjects, and by professional female ballet dancers. To accomplish the return task, subjects were free to use the egocentered reference frame (inversion) or the exocentered one (completion). The results show that with inversion all kinetic parameters were reproduced, whereas the completion performance was highly variable. Although inversion was the default strategy, female subjects used more completions than male subjects, and female dancers still more, although not more accurately. The high variability noted in completion shows a deficiency in integrating vestibular signals for updating the egocentric representation of an external target during passive body rotations, even in dancers. Furthermore, with completions after 180 degrees stimuli, the results suggest that both ego- and exocentered reference frames cannot be used simultaneously.