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1. Most recording studies on the role of the monkey superior colliculus (SC) in eye movement generation have so far indicated that the code of the recruited population of cells is a fixed vector command representing the desired saccadic eye displacement vector, irrespective of the position of the eyes in the orbit. Experimental evidence from(More)
In three rhesus monkeys three-dimensional eye positions were measured with the dual search coil technique. Recordings of spontaneous eye movements were made in the light and in the dark, with the monkeys in different static roll or pitch positions. Eye positions were expressed as rotation vectors. In all static positions eye rotation vectors were confined(More)
1. In the alert monkey, 74 neurons in the vestibular nuclei were investigated during sinusoidal rotation about a vertical axis at frequencies between 0.003 and 0.5 Hz. Phase and gain were determined by a fast Fourier analysis program. 2. Phase advance, relative to turntable velocity, was small between 0.05 and 0.5 Hz. At lower frequencies phase advance(More)
Habituation of the vestibular system by repeated steps of angular velocity leads to a shortening of nystagmus. These steps can be broken down into different frequency sinusoids. High-frequency sinusoidal rotation (above 0.1 Hz) generally was found to be ineffective, while low-frequency stimulation (0.0015-0.05 Hz) led to a dramatic shortening of time(More)
Saccades are controlled by neurons in the brainstem reticular formation that receive input from the superior colliculus and cortex. Recently two quantitative models have been proposed for the role of the colliculus in the generation of three-dimensional eye movements. In order to test these models, three-dimensional eye movements were measured in the alert(More)
An important problem in motor control is how the nervous system deals with redundant degrees of freedom. It has been well documented that voluntary eye movements are constrained to a plane by Listing's law. Recent evidence has indicated that Listing's law is implemented downstream from the motor superior colliculus (SC), but controversy exists whether this(More)
In experimentally naive monkeys the horizontal vestibulo-ocular-reflex (VOR) has a time constant which is in the range of 40--60 s. It can be measured as the nystagmus decline after pulses of angular acceleration, or from the transfer functions obtained from sinusoidal rotation with different frequencies. When frequencies below 0.1 Hz are applied,(More)
Recordings from neurons of the vestibular nuclei were performed in alert monkeys. Type I and type II units were identified by rotating the monkey about a vertical axis. Al neurons responded also when only the visual surround was rotated around the stationary monkey. The combination of visual and vestibular stimulation points towards non-algebraic summation(More)