Short-term vestibulo-ocular adaptation: influence of context.
A number of mechanisms and strategies are used to help an individual compensate for loss of labyrinthine function. One important example is the ability to produce a preplanned motor response that anticipates the motion of the head and so compensates for it. Closely tied to this phenomenon is the gating, in or out, of a learned response on the basis of the context in which it must occur. This issue is particularly relevant to designing programs of physical therapy that optimize performance for natural behavior. Here we discuss a model of short-term vestibulo-ocular adaptation-adjustment of vestibulo-ocular phase (timing)-and how it can be used to study context-dependent vestibulo-ocular learning. We will show how vestibulo-ocular phase can be adjusted by selectively altering the common velocity-to-position ocular motor neural integrator for one type of eye movement (vestibular) and not for another (saccades), or for one type of head movement (sinusoidal) and not for another (step). These results are another example of the remarkable flexibility of the vestibulo-ocular adaptive mechanism and further show that the fundamental process of integration for eye movements can be modified according to the pattern of afferent information.
Department of Neurology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.
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Kramer
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Shelhamer
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Zee
D000222:Adaptation, Physiological / Q000502:physiology*; D000344:Afferent Pathways / Q000503:physiopathology; D003463:Cues; D007758:Ear, Inner / Q000503:physiopathology*; D005133:Eye Movements / Q000502:physiology*; D006801:Humans; D007858:Learning / Q000502:physiology*; D009048:Motor Skills / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology; D026741:Physical Therapy Modalities / Q000379:methods; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology*; D014724:Vestibular Function Tests