There is strong evidence that the brain can use an internally generated copy of motor commands, a corollary discharge, to guide rapid sequential saccades. Much of this evidence comes from the double-step paradigm: after two briefly flashed visual targets have disappeared, the subject makes two sequential saccades to the targets. Recent studies on the monkey revealed that amplitude variations of...

In previous experiments, we showed that cells in the parietal reach region (PRR) in monkey posterior parietal cortex code intended reaching movements in an eye-centered frame of reference. These cells are more active when an arm compared with an eye movement is being planned. Despite this clear preference for arm movements, we now report that PRR neurons also fire around the time of a saccade. ...

We compared the effects of intracortical microstimulation (ICMS) of the lateral wall of the intraparietal sulcus (LIP) with those of ICMS of the frontal eye field (FEF) on monkeys performing oculomotor tasks. When ICMS was applied during a task that involved fixation, contraversive saccades evoked in the LIP and FEF appeared similar. When ICMS was applied to the FEF at the onset of voluntary sa...

Whether a link exists between the two orienting processes of saccade preparation and visuospatial attention has typically been studied by using either sensory cues or predetermined rules that instruct subjects where to allocate these limited resources. In the real world, explicit instructions are not always available and presumably expectations shaped by previous experience play an important ro...

Shifts in the direction of gaze are accomplished by different kinds of saccades, which are elicited under different circumstances. Saccade types include targeting saccades to simple jumping targets, delayed saccades to visible targets after a waiting period, memory-guided (MG) saccades to remembered target locations, scanning saccades to stationary target arrays, and express saccades after very...

BACKGROUND Persons with Parkinson disease (PD) experience difficulty turning, leading to freezing of gait and falls. We hypothesized that saccade dysfunction may relate to turning impairments, as turns are normally initiated with a saccade. OBJECTIVE Determine whether saccades are impaired during turns in PD and if characteristics of the turn-initiating saccade are predictive of ensuing turn ...

Trans-saccadic memory consists of keeping track objects’ locations and features across saccades; pre-saccadic information is remembered compared with post-saccadic information. It has been shown to have limited resources involve attention respect the selection objects features. In support, a previous study showed that recognition distinct in visual scene impaired when are relevant thus already ...

We provide evidence that the saccadic system can simultaneously program two saccades to different goals. We presented subjects with simple visual search displays in which they were required to make a saccade to an odd-colored target embedded in an array of distractors. When there was strong competition between target and distractor stimuli (due to color priming from previous trials), subjects w...

The planning of the refixation saccade, i.e. the second saccade on 9- and 11-letter-strings, was assessed in two reading experiments that examined the influence of a length change at different times during the first fixation on a letter string. The results showed that the saccadic system was able to modify the first motor program if the new length information was available 150-190 ms before the...