Pulsed linear acceleration as a vestibular stimulus in electrophysiological investigations

Abstract

A simple method of generating precisely defined pulsed linear acceleration stimuli was developed and used to study vestibular responses to cranial acceleration. Electromechanical shakers were coupled to a stimulus platform. The platform, in turn, was used to couple stimuli to the skull. Movements were controlled by a voltage waveform ( V(t)) applied to shakers. Software algorithms were used to synthesize voltage functions ( V(t)). The resulting acceleration was monitored [ a(t)] and used to generate velocity [ v(t)] and position [ x(t)] functions (first and second integrals of a(t), respectively). The characteristics of stimuli used in physiological experiments are described. The system provides precise control of the timing and amplitude of acceleration, velocity and position pulses to the cranium and has proved to be valuable in developing noninvasive electrophysiological measures of peripheral and central vestibular function.