Voluntary Saccades in Normal and in Dopamine-Deficient Subjects

2015 ◽  
pp. 59-68 ◽  
Author(s):  
Okihide Hikosaka ◽  
Hideki Fukuda ◽  
Masaya Segawa ◽  
Yoshiko Nomura
Keyword(s):  
Voluntary Saccades

Endogenously Generated and Visually Guided Saccades after Lesions of the Human Frontal Eye Fields

1994 ◽  
Vol 6 (4) ◽  
pp. 400-411 ◽  
Author(s):  
Avishai Henik ◽  
Robert Rafal ◽  
Dell Rhodes
Keyword(s):  
Prefrontal Cortex ◽  
Visual Display ◽  
Covert Attention ◽  
Visual Signal ◽  
Frontal Eye Fields ◽  
Opposite Pattern ◽  
Control Subjects ◽  
Key Press ◽  
Reflexive Saccades ◽  
Voluntary Saccades

Nine patients with chronic, unilateral lesions of the dorso-lateral prefrontal cortex including the frontal eye fields (FEF) made saccades toward contralesional and ipsilesional fields. The saccades were either voluntarily directed in response to arrows in the center of a visual display, or were reflexively summoned by a peripheral visual signal. Saccade latencies were compared to those made by seven neurologic control patients with chronic, unilateral lesions of dorsolateral prefrontal cortex sparing the FEF, and by 13 normal control subjects. In both the normal and neurologic control subjects, reflexive saccades had shorter Latencies than voluntary saccades. In the FEF lesion patients, voluntary saccades had longer latencies toward the contralesional field than toward the ipsilesional field. The opposite pattern was found for reflexive saccades: latencies of saccades to targets in the contralesional field were shorter than saccades summoned to ipsilesional targets. Reflexive saccades toward the ipsilesional field had abnormally prolonged latencies; they were comparable to the latencies observed for voluntary Saccades. The effect of FEF lesions on saccacles contrasted with those observed in a second experiment requiring a key press response: FEF lesion patients were slower in making key press responses to signals detected in the contralesional field. To assess covert attention and preparatory set the effects of precues providing advance information were measured in both saccade and key press experiments. Neither patient group showed any deficiency in using precues to shift attention or to prepare saccades. The FEF facilitates the generation of voluntary saccatles and also inhibits reflexive saccades to exogenous signals. FEF lesions may disinhibit the ipsilesional midbrain which in turn may inhibit the opposite colliculus to slow reflexive saccades toward the ipsilesional field.

Acute activation and inactivation of macaque frontal eye field with GABA-related drugs

1995 ◽  
Vol 74 (6) ◽  
pp. 2744-2748 ◽  
Author(s):  
E. C. Dias ◽  
M. Kiesau ◽  
M. A. Segraves
Keyword(s):  
Injection Site ◽  
Rhesus Monkeys ◽  
Frontal Eye Field ◽  
Surgical Removal ◽  
Gamma Aminobutyric Acid ◽  
Eye Field ◽  
Distribution Of Points ◽  
Direction Opposite ◽  
Voluntary Saccades

1. This project tests the behavioral effects of reversible activation and inactivation of sites within the frontal eye field of rhesus monkeys with microinjections of the gamma-aminobutyric acid (GABA)-related drugs bicuculline and muscimol. 2. Muscimol injections impaired the monkeys' ability to make both visually and memory-guided saccades to targets at the center of the area represented by the injection site. The latencies of saccades to targets in regions flanking the injection were increased. For memory-guided saccades, saccades in the direction opposite to that represented by the injection site, were made with shorter latency than controls and often occurred before the movement cue. 3. Bicuculline injections produced irrepressible saccades equivalent to the saccade vector represented by the injection site, often in a staircase of several closely spaced movements. 4. Both substances decreased the accuracy of fixation of a central light. The distribution of points of fixation on different trials was diffuse, and the angle of gaze tended to deviate towards the side of the injection. 5. The results of these acute injections are similiar to those observed in the superior colliculus and are much more substantial than the effects observed in the long term after surgical removal of the frontal eye field. The results of this study promote a central role for the frontal eye field in the generation of all voluntary saccades and in the control of fixation.

Cortical control of voluntary saccades in Parkinson's disease and pre-emptive perception

2012 ◽  
Vol 18 ◽  
pp. S100-S103 ◽  
Author(s):  
M.A. Javaid ◽  
V. Amassian ◽  
S. Glazman ◽  
A. Fesharaki ◽  
D. Stefanov ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cortical Control ◽  
Voluntary Saccades

Effect of Non-Target Stimuli upon Length of Voluntary Saccades

1972 ◽  
Vol 34 (2) ◽  
pp. 499-508 ◽  
Author(s):  
Stanley Coren ◽  
Paul Hoenig
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Center Of Gravity ◽  
Saccade Length ◽  
Task Requirements ◽  
Voluntary Saccades

The length of initial voluntary saccades to a target were measured in three experiments. It was found that saccade length varied as a function of the number, locus and distance of non-target stimuli present in the visual field. Eye movements tended to be directed toward the “center of gravity” of the stimuli close to the target. These systematic changes seem to be independent of task requirements for acuity. Some implications are discussed.

Time Course of Visual Inhibition during Voluntary Saccades*†

1968 ◽  
Vol 58 (4) ◽  
pp. 562 ◽  
Author(s):  
Frances C. Volkmann ◽  
Amy M. L. Schick ◽  
Lorrin A. Riggs
Keyword(s):  
Time Course ◽  
Voluntary Saccades
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