The Motor System that Sees the World

The oculomotor system is an ancient and crucial motor system. It is unique among motor control systems in that we know many details of the circuitry underlying the generation of eye movements, and can measure them with a high degree of accuracy. Classical research focused on oculomotor biomechanics and brainstem control mechanisms continues to provide exciting findings. At the same time this extensive body of knowledge has allowed the field to evolve and expand so that it now includes studies of the central mechanisms underlying higher order processing. For example, much work in this field now focuses on understanding the cortical control of eye movements, and uses the oculomotor system as a model to study higher brain functions, such as attention, perception and decision-making. Other areas of active study include the integration of oculomotor subsystems and coordination with other motor systems, the function and mechanical constraints produced by extraocular muscle pulleys, the transformation of visual, auditory and other sensory signals into motor commands, and investigations of the neurobiology of ocular motility disorders. The number of techniques being used to study the oculomotor system has similarly increased over the years. Recently developed approaches combining imaging, behavioural, cellular, molecular and genetic techniques are now being used in conjunction with anatomical, theoretical and electrophysiological approaches to provide novel insights into the workings of this system. In sum, the oculomotor system continues to serve as an ideal testing site for new concepts and techniques related to motor control.