The vestibulo-ocular reflex (VOR) allows animals to maintain stable gaze during head rotations by generating compensatory eye rotations. The VOR is typically tested using sinusoidal head rotation, and VOR gain is calculated as the ratio of the amplitude of eye to head rotational velocity. Through habituation, prolonged exposure to lower frequency sinusoidal head rotation in the dark decreases V...

OBJECTIVE Determining the blood flow through intra and extra-cranial arteries during neck extension may be helpful but is a controversial issue. We aimed to elucidate the changes in cerebral blood flow related to head positioning during thyroid surgery by carotid Doppler examination and regional oxygen saturation variations. METHODS Thirty patients were recruited to the study. Patients were p...

Rats use rhythmic movements of their vibrissae (whiskers) to tactually explore their environment. This "whisking" behavior has generally been reported to be strictly synchronous and symmetric about the snout, and it is thought to be controlled by a brainstem central pattern generator. Because the vibrissae can move independently of the head, however, maintaining a stable perception of the world...

OBJECTIVE To determine whether saccadic velocity in the suppression head impulse paradigm (SHIMP) test is a reliable indicator of vestibular loss at the acute and at the chronic stage in patients suffering from different vestibular pathologies. METHODS Thirty-five normal subjects and 57 patients suffering from different vestibular pathologies associated with unilateral vestibular loss (UVL) o...

Limb movement is smooth and corrections of movement trajectory and amplitude are barely noticeable midflight. This suggests that skeletomuscular motor commands are smooth in transition, such that the rate of change of acceleration (or jerk) is minimized. Here we applied the methodology of minimum-jerk submovement decomposition to a member of the skeletomuscular family, the head movement. We exa...

OBJECTIVE Concussion in professional football was studied with respect to impact types and injury biomechanics. A combination of video surveillance and laboratory reconstruction of game impacts was used to evaluate concussion biomechanics. METHODS Between 1996 and 2001, videotapes of concussions and significant head impacts were collected from National Football League games. There were clear ...

Single neuron recording studies have demonstrated the existence of hippocampal spatial view neurons which encode information about the spatial location at which a primate is looking in the environment. These neurons are able to maintain their firing even in the absence of visual input. The standard neuronal network approach to model networks with memory that represent continuous spaces is that ...

Background and Aim: The video head-impulse test (vHIT) measures the vestibulo-ocular reflex (VOR) driven by each semicircular canal, following high-acceleration head rotations. The main measurable response is the ratio of eye movement velocity to the angular head velocity, which reflects canal function. Although normative data is available for VOR gain, most studies only report horizontal VOR c...

The purpose of this study was to determine if body position, weight transfer, and/or pelvis/trunk rotations changed as a result of a golf specific fatiguing protocol and whether these changes affected resultant club head velocity at impact and shot consistency. Six male golfers and one female golfer participated in the study, who had a mean age, height, and body mass of 23.9 +/- 3.9 years, 177....