The quick phases of full-field optokinetic nystagmus (OKN) not only reset the eyes, but also move them in an anticompensatory direction (that is, in the opposite direction to stimulus movement, “contraversion”).1–7 Although recognized as an oculomotor phenomenon, contraversion is poorly understood, and it has been suggested as a strategy for directing the line of sight into the visual field fro...

The effects of an optokinetic background on pursuit eye movements was studied in four normal human subjects and seven patients with impaired pursuit and/or optokinetic nystagmus (OKN). Eye movements were recorded by DC electro-oculography and eye movement velocity was analyzed by a digital, microprocessor system. Tracking of a small laser target was performed against a featureless, white screen...

Optokinetic nystagmus (OKN) is a reflexive eye movement with target-following slow phases (SP) alternating with oppositely directed fast phases (FP). We measured the following from OKN in three humans: FP beginning and ending positions, amplitudes, and intervals and SP amplitudes and velocities. We sought to predict future values of each parameter on the basis of past values, using state-space ...

Using electronystagmography, we tested 100 patients (ages 65-80 years) manifesting the clinical signs of presbyvertigo, for the purpose of demonstrating their visuoocular reflexes. We administered not only simple optokinetic and eye-tracking stimuli but caloric modification of each one as well (with contrary directed optokinetic trace movement). The results were compared with those obtained in ...

Infant color vision is poor, and most psychophysical experiments agree that infant color vision emerges between ages 3 weeks and 3 months. Presumably, the color vision of infants is poor during the months immediately after it has emerged. We have tested two alternative explanations for the poor color vision of infants: (1) there is a special critical immaturity within the color pathways of infa...

Psychophysical studies of children deprived of early visual experience by dense cataracts indicate that there are multiple sensitive periods during which experience can influence visual development. We note three sensitive periods within acuity, each with different developmental time courses: the period of visually-driven normal development, the sensitive period for damage, and the sensitive pe...

When gratings moving in different directions are presented separately to the two eyes, we typically perceive periods of the combination of motion in the two eyes as well as periods of one or the other monocular motions. To investigate whether such interocular motion combination is determined by the intersection-of-constraints (IOC) or vector average mechanism, we recorded both optokinetic nysta...

As a potential exemplar for understanding how volitional actions emerged from reflexes, we studied the relationship between an ancient reflexive gaze stabilization mechanism (optokinetic nystagmus [OKN]) and purposeful eye movements (saccades) that target an object. Traditionally, these have been considered distinct (except in the kinematics of their execution) and have been studied independent...

Although it is now well established that a variety of ocular and systemic diseases, including diabetes, are harmful to the SWS cone pathway, causing a decrease in SW sensitivity,"the site(s) of the loss is not well known. The loss in SW sensitivity in diabetes has been variously attributed to changes in the lens, loss of SWS cone receptors due to their greater vulnerability to insult, the reduc...