During natural behavior humans continuously adjust their gaze by moving head and eyes, yielding rich dynamics of the retinal input. Sensory coding models, however, typically assume visual input as smooth or a sequence of static images interleaved by volitional gaze shifts. Are these assumptions valid during free exploration behavior in natural environments? We used an innovative technique to si...

The vestibular system detects motion of the head in space and in turn generates reflexes that are vital for our daily activities. The eye movements produced by the vestibulo-ocular reflex (VOR) play an essential role in stabilizing the visual axis (gaze), while vestibulo-spinal reflexes ensure the maintenance of head and body posture. The neuronal pathways from the vestibular periphery to the c...

Because of limitations in the oculomotor range, many gaze shifts must be accomplished using coordinated movements of the eyes and head. Stimulation and recording data have implicated the primate superior colliculus (SC) in the control of these gaze shifts. The precise role of this structure in head movement control, however, is not known. The present study uses reversible inactivation to gain i...

OBJECTIVE To determine the effect of subthalamic stimulation on visually triggered eye and head movements in patients with Parkinson's disease (PD). METHODS We compared the gain and latency of visually triggered eye and head movements in 12 patients bilaterally implanted into the subthalamic nucleus (STN) for severe PD and six age-matched control subjects. Visually triggered movements of eye ...

We report neck muscle activity and head movements evoked by electrical stimulation of the superior colliculus (SC) in head-unrestrained monkeys. Recording neck electromyography (EMG) circumvents complications arising from the head's inertia and the kinetics of muscle force generation and allows precise assessment of the neuromuscular drive to the head plant. This study served two main purposes....

PURPOSE To describe a video-based head-tracking technique to compensate for torsional, horizontal, and vertical in-plane head movements during pupil/iris-tracking video-oculography with a tilting haploscope. METHODS Custom software was developed for image acquisition and off-line analysis for a novel haploscopic viewing device. Head movements were constrained to the frontal plane with the use...

The proposed system is for designing progressive lenses. This method permits generation of lens design based on the head and eye movements of an individual. For this a camera is used for imaging the head and eye of a person. It relies on tracking algorithms to robustly track a person’s head and eye movements. This system classifies rotation in all viewing directions, and detects head movements....

introduction:  stereotactic  radiosurgery  is  a  technique  for  the  treatment  of  intracranial  lesions  with  highly  collimated  x-ray  beam.  linac-based  radiosurgery  is  currently  performed  by  two  techniques:  couch or pedestal mounted. in the first technique, a device is required to affix patient's head to a couch  and  moreover  to  translate  it  accurately.  structure  of...

This paper summarizes recent experiments conducted by the authors - experiments that studied the behavioral characteristics of large gaze shifts and the neural bases of coordinated movements of the eyes and head.