Optokinetic eye movements elicited by an apparently moving visual pattern in guinea pigs.

Based on known anatomical and physiological properties, guinea pigs could be expected to show a lack of cortical impact on the basic properties of optokinetic nystagmus (OKN) such as eye movements elicited by a rotating striped drum. The present study aimed to clarify the question of whether the guinea pig's brainstem-mediated circuit is capable of generating horizontal OKN with the animal binocularly viewing a stationary stroboscopically illuminated striped pattern (apparent-motion OKN). A striped drum with a pattern periodicity of 2.

The effect of d-amphetamine on optokinetic nystagmus in the guinea pig.

The effect of d-amphetamine oral administration in doses of 1-2.5 mg/kg on horizontal optokinetic nystagmus (OKN) and after nystagmus (OKAN) was investigated in the guinea pig. Eye movements were recorded by means of the electromagnetic search-coil technique.

Vestibular and vestibulo-proprioceptive perception of motion in the horizontal plane in blindfolded man--III. Route inference.

The inference of direction and length of a subsequent route during performance of a triangle completion task was studied in blindfolded human subjects. Subjects were transported and walked with guidance along two sides of left- and right-oriented isosceles triangles. Subjects had to walk without assistance along the inferential bases of triangles back to a starting point.

Vestibular and vestibulo-proprioceptive perception of motion in the horizontal plane in blindfolded man--II. Estimations of rotations about the earth-vertical axis.

Perception of angular displacement in the horizontal plane was studied in blindfolded human subjects. Subjects sitting on a rotating chair were turned and turned themselves about the earth-vertical axis. Magnitudes of left- and rightward directed rotations were in steps of 30 degrees and overlapped an entire circle.

Vestibular and vestibulo-proprioceptive perception of motion in the horizontal plane in blindfolded man--I. Estimations of linear displacement.

Perception of linear displacement in the horizontal plane was studied in blindfolded human subjects. Subjects were transported and walked with guidance along 2-6 m straight lines and then had to retrace these paths walking backwards. Subjects solved a double orientational task: firstly, they defined the direction of the backward path and, secondly, estimated its length.