The laboratory focuses on neural processes that control human whole-body actions, and the disorders of these processes that result from damage to the central nervous system and from ageing. The actions of interest include standing, walking, rising from a seat, and reaching; the neurological disorders include Parkinson’s disease, stroke, and cerebellar disease. Of particular interest are the neural processes that combine sensory information from vestibular organs, eyes, muscles and skin to compute the motor instructions necessary for each action, together with the roles played by the cerebellum, basal ganglia, brainstem and cerebral cortex in these computations.

The principal research question reduces to: How is multi-sensory information used to control whole-body motor function? To study this we have developed methods for delivering independent perturbations to single sensory channels and measuring the whole-body responses during unconstrained behaviour. A key component of this work has been the development of vestibular stimulation techniques using electrical stimuli (galvanic and stochastic vestibular stimulation; GVS, SVS) and bone-conducted sound comprising high-frequency (500Hz) vibratory mechanical stimuli. We have started to understand the nature of the virtual head movements that these stimuli produce and how the brain interprets them, and have applied the stimuli to probe vestibular contributions to the maintenance of standing balance, the steering of gait, and the control of voluntary movements. We are also using these pure vestibular stimuli in conjunction with other sensory modalities to investigate multi-sensory integrative processes.

The main research tools consist of non-invasive sensory stimulation techniques coupled with 3D motion-capture technology. The recording equipment includes eight CODA sensor units each of which can determine the 3D coordinates of up to 56 infrared emitting body markers. This kinematic information is combined with force data from up to seven Kistler force plates and two JR3 6-axis force handles, electromyographic data transmitted wirelessly from up to 32 muscles using a Delsys EMG telemetry system, and gaze direction data obtained from a head-free ASL gaze tracking device.

 

Keywords: Balance, Basal ganglia, Behaviour, Brain, Cutaneous, Gait, Motor control, Motor learning, Movement disorders, Muscle tone, Neurophysiology, Neuroscience, Proprioception, Psychophysics, Sensorimotor, Vestibular, Vision

Conditions: Ataxias, Charcot-Marie-Tooth disease, Dystonia, Friederich's ataxia, Gait and balance disorders, Ischaemic stroke , Multiple system atrophy, Neurodegenerative diseases, Parkinson's disease, Spinocerebellar ataxia, Tremor

Methods: Behavioural analysis, Electromyography, Eye movement recording, Galvanic vestibular stimulation, Goal-directed behaviour analysis, Motion capture, Psychophysics, Stochastic vestibular stimulation, Virtual reality