Horizontal and vertical smooth pursuit was compared with otolith-ocular responses in 11 patients with cerebellar ataxia and 21 normal subjects using three-dimensional magnetic search coil eye movement recordings. Otolith-ocular responses were investigated during off-vertical axis rotation. This stimulus induces nystagmus consisting of the exponentially decaying canalicular response, and an eye-...

In most visuomotor tasks in which subjects have to reach to visual targets or move the hand along a particular trajectory, eye movements have been shown to lead hand movements. Because the dynamics of vergence eye movements is different from that of smooth pursuit and saccades, we have investigated the lead time of gaze relative to the hand for the depth component (vergence) and in the frontal ...

Illusions developed by magicians are a rich and largely untapped source of insight into perception and cognition. Here we show that curved motion, as employed by the magician in a classic sleight of hand trick, generates stronger misdirection than rectilinear motion, and that this difference can be explained by the differential engagement of the smooth pursuit and the saccadic oculomotor system...

Simple reaction times (RTs) are typically faster than choice reaction times and increase with uncertainty according to Hick's law. Here we show that smooth pursuit eye movement RTs show no effect of SR uncertainty while joystick tracking shows a step change between SRT and CRT, but no significant increases beyond two choices. The results suggest there is a benefit to pre-programming joystick tr...

A fundamental question in primate neurobiology is to understand to what extent motor behaviors are driven by shared neural signals that also support conscious perception or by independent subconscious neural signals dedicated to motor control. Although it has clearly been established that cortical areas involved in processing visual motion support both perception and smooth pursuit eye movement...

When a person tracks a small moving object, the visual images in the background of the visual scene move across his/her retina. It, however, is possible to estimate the actual motion of the images despite the eye-movement-induced motion. To understand the neural mechanism that reconstructs a stable visual world independent of eye movements, we explored areas MT (middle temporal) and MST (medial...

Subjects were asked to track, with their eyes or their hand, the movement of a target that maintained a constant speed and made a single, abrupt change in direction. The tracking speed and direction of motion after the step change in target direction were compared for the eyes and the hand. After removal of the saccades from the eye movement records, it was found that in both cases, there was a...

When subjects localize a flash relative to another stationary stimulus, the flash appears displaced in the direction of nearby motion signals (position capture; Whitney and Cavanagh, 2000 Nature Neuroscience 3 954-959). Our previous study had suggested that the position capture is larger for a flash presented ahead of a moving stimulus than for a flash behind it (Watanabe et al, 2003 Perception...

We quantified the horizontal pursuit and saccadic function of 14 parkinsonian patients and 10 normal subjects matched for age. Eight patients had mild, and 6 advanced disease. Ocular motor deficits were more marked in patients with advanced disease. Saccadic reaction times and postsaccadic refractory periods were prolonged. Peak saccadic velocities were significantly reduced. Slow saccades may ...

Eye-target synchronization is critical for effective smooth pursuit of a moving visual target. We apply the nonlinear dynamical technique of stochastic-phase synchronization to human visual pursuit of a moving target, in both normal and mild traumatic brain-injured (mTBI) patients. We observe significant fatigue effects in all subject populations, in which subjects synchronize better with the t...