This book contains the proceedings of the Sixth Extraordinary Meeting of the Barany Society, Imperial College, London, in September 1977, wherein distinguished scholars in vestibular research met to honor Robert Barany, Nobel laureate, after whom the society was named when founded in 1960. There were four main themes of the conference: (1) problems of head stability, (2) central control of vestibulo-oculomotor function, (3) positional nystagmus, and (4) signal processing in the evaluation of vestibular mechanisms. Free papers, covering other aspects of vestibular function of current interest, were also presented. The first section, "Primary Afterents," addresses the problem of head stability with a volume of work that shows the close relationships between the vestibular and proprioceptive systems at different levels within the CNS. The papers in neurophysiology concentrate on single cell responses within the vestibular system in assessing central control of vestibulo-ocular function. In subsequent chapters, human clinical experience with