Eye or head rotation would influence perceived heading direction if it were coded by cells tuned only to retinal flow patterns that correspond to linear self-movement. We propose a model for heading detection based on motion templates that are also Gaussian-tuned to the amount of rotational flow. Such retinal flow templates allow explicit use of extra-retinal signals to create templates tuned t...

The ability to simultaneously move in the world and maintain stable visual perception depends critically on the contribution of vestibulo-ocular reflexes (VORs) to gaze stabilization. It is traditionally believed that semicircular canal signals drive compensatory responses to rotational head disturbances (rotational VOR), whereas otolith signals compensate for translational movements [translati...

Head direction cells in the rat postsubiculum fire in relation to the momentary directional heading of the animal, with each cell firing only when the animal faces in one particular direction. To understand how this signal might be generated, one useful step is to discover what other cell types, in addition to the head direction cells, may exist in the postsubiculum, since these cells might be ...

Advantage was taken of differences in the electrical excitability of vestibular-nerve fibers to characterize the afferent input to the canal-related vestibulo-ocular reflex. Large anodal (inhibitory) currents, when delivered to both ears, result in a selective, reversible ablation of irregular afferents. Their background discharge and responses to head rotations are temporarily abolished. The s...

1. Humans may visually track a moving object either when they are stationary or in motion. To investigate visual-vestibular interaction during both conditions, we compared horizontal smooth pursuit (SP) and active combined eye-head tracking (CEHT) of a target moving sinusoidally at 0.4 Hz in four normal subjects while the subjects were either stationary or vibrated in yaw at 2.8 Hz. We also mea...

BACKGROUND Soccer heading is using the head to directly contact the ball, often to advance the ball down the field or score. It is a skill fundamental to the game, yet it has come under scrutiny. Repeated subclinical effects of heading may compound over time, resulting in neurologic deficits. Greater head accelerations are linked to brain injury. Developing an understanding of how the neck musc...

conclusions the study revealed the significance of anthropometric variables related to heading, such as age and head perimeter. therefore, it was concluded that these variables should be considered when teaching and practicing the heading technique with players of different ages and anthropometric sizes. results significant correlations existed between the force exerted on the head during headi...

In stalk-eyed flies (Diopsidae), the eyes are positioned at the end of rigid peduncles protruding laterally from the head. Sexual selection for eye span in male Cyrtodiopsis dalmanni results in eye span that exceeds body length and exceeds the eye span of females. We studied whether the twofold higher moment of inertia (MOI) of the male head results in a reduced head rotation velocity during tu...

17 Maintaining a constant representation of our heading as we move through the world requires the 18 accurate estimate of spatial orientation. As one turns (or is turned) toward a new heading, signals 19 from the semi-circular canals are relayed through the vestibular system to higher-order centers 20 that encode head direction. To date, there is no direct electrophysiological evidence confirmi...

abstract background: sperm parameters and motion kinetics are affected by cryopreservation. objective: the main purpose of the current study was to determine the effect of different concentrations of trolox as an antioxidant to freezing-thawing procedure on human sperm kinematic parameter. materials and methods: semen was collected from 20 normal donors and divided into five aliquots prior to c...