The concept of the orienting reflex is discussed from the historical perspective. The following conclusions are proposed: (1) in accordance with the spirit of Pavlov's concept the orienting reflex is a response to a stimulus unexpected in a given situation; (2) the reflex consists of targeting, arousal and perceptual components; (3) the reflex has three stages, which in the targeting component ...

VOR parameters were compared in subjects at the extremes of the seasickness susceptibility scale. Thirty-nine subjects highly susceptible to seasickness and 30 nonsusceptible subjects participated in the study. The VOR was evaluated by the Sinusoidal Harmonic Acceleration (SHA) test at frequencies of 0.01, 0.02, 0.04, 0.08, and 0.16 Hz. In subjects susceptible to seasickness, VOR gain was signi...

Extraretinal and visual afferent sources of ocular fixation instability were investigated in a group of strabismic amblyopes. Extraretinal drift-bias was revealed by fixational eye movements in darkness. The resulting dark drift-bias was highly correlated with an imbalance of the vestibulo-ocular reflex (VOR). No significant difference in dark drift-bias or VOR imbalance was found between norma...

KEY POINTS Directionality, inherent to movements, has behavioural and neuronal correlates. Direction of vestibular stimulation determines motor learning efficiency. Vestibulo-ocular reflex gain-increase correlates with Purkinje cell simple spike potentiation. The locus of neural correlates for vestibulo-ocular reflex adaptation is paradigm specific. ABSTRACT Compensatory eye movements elicite...

Dissociated vertical divergence (DVD) is an ocular motor disorder characterized by a slow, upward drift of 1 eye when the other eye is fixating a target. I propose that DVD is a dorsal light reflex in which asymmetrical visual input to the 2 eyes evokes a vertical divergence movement of the eyes. This primitive visuo-vestibular reflex functions as a righting response to restore vertical orienta...