Our main aim is to understand the principles that govern human sensory and motor integration, its plasticity and its development.  Although sensory processes (eg. vision, hearing ) and motor control (eg. eye movements, arm reaching, speech articulation) are often treated as separate domains, they are inextricably linked at all levels of the nervous system - from basic  mechanisms, adaptive control, to cognition.  Movement is guided by sensory feedback and sensory expectation, and our sensations are determined by how we move.
Sensorimotor control is highly plastic at all ages, and especially influenced by early development through interactions between genes and environment (developmental plasticity).  Often early human plasticity can only be observed through abnormalities of development.

Early visual deprivation can lead to permanent eye movement disorders,  as in congenital nystagmus.  Conversely abnormal eye movement control in early infancy can lead to permanent sensory disturbances, as in amblyopia.  Equally interesting is why some conditions are not self-corrected by plasticity.

Our computational approach relies heavily on treating sensorimotor behaviour as an optimal control problem, in which behaviour is considered to be the product of goal-driven plasticity and/or evolutionary optimization. We use mathematical tools (calculus of variations, optimal control theory) and  numerical techniques to find nature’s cost functions.

Current Computational Modelling Studies

• Cost functions for developmental plasticity .
• The origins of proportional noise (PN).
• Optimal stimulus movement  for space-time receptive fields.
• Modelling of timing.

Current Experimental Work

• Developing methods for measuring eye movements from the very young .
• Development of optokinetic nystagmus.
• Timing of saccades.
• Using fMRI to study how prediction errors are controlled.

Current Clinical Studies

• Auditory dysfunction in children with oculomotor deficits.
• Re-classifying congenital nystagmus waveforms.
• Distinguishing between sensory and motor disturbances in children with poor visual responsiveness.
• Timing deficits in children with saccade initiation failure (ocular motor apraxia).

For more details go to the Harris lab website