The vestibulo-ocular reflex (VOR) is an involuntary eye movement evoked by head movements. It is also influenced by viewing distance. This paper presents a hybrid nonlinear bilateral model for the horizontal angular vestibulo-ocular reflex (AVOR) in the dark. The model is based on known interconnections between saccadic burst circuits in the brainstem and ocular premotor areas in the vestibular...

Optimal human performance depends upon integrated sensorimotor and cognitive functions, both of which are known to be exquisitely sensitive to loss of sleep. Under the microgravity conditions of space flight, adaptation of both sensorimotor (especially vestibular) and cognitive functions (especially orientation) must occur quickly--and be maintained--despite any concurrent disruptions of sleep ...

We report on a blink reflex abnormality observed in two patients, which provides additional information on the central pathways mediating this reflex. Autopsy was performed in one patient and MRI in the other. In the first patient there was a small lesion at the dorsal middle third of the lateral tegmental field and in the second patient at the level of the dorsal lower third of the medulla obl...

It is assumed that the immobility reflex (IR) evoked in adult rats by sensory stimulation does not exceed a few seconds. However, we easily achieved a longer lasting (up to 3 min or longer) immobility state in most of the tested rats when they were grasped by hand and lifted to a specific upright position. Twenty male rats originating from two different albino populations could remain immobiliz...

The nuchocephalic reflex, previously undescribed, was investigated in a controlled study of 146 subjects ranging in age from 11 hours to 94 years. In 110 subjects over 16 years of age, the presence of the reflex was correlated directly with evidence of diffuse cerebral dysfunction as measured by a shortened form of the Wechsler Adult Intelligence Scale. Thirty-six children were studied from the...

Reading performance during standing and walking was assessed for information presented on earth-fixed and head-fixed displays by determining the minimal duration during which a numerical time stimulus needed to be presented for 50% correct naming answers. Reading from the earth-fixed display was comparable during standing and walking, with optimal performance being attained for visual character...

OBSERVATIONS ON TEMPORAL VARIATION IN MONOSYNAPTIC REFLEX RESPONSE IN THE ACUTELY DECAPITATE CAT INDICATE THE FOLLOWING: 1. Frequency distribution of response amplitude has a nearly normal form often with some degree of negative skewness. Response variation differs only moderately in form and magnitude from one preparation to another. 2. Temporal variation remains essentially constant at differ...