Vestibular-Contingent Voluntary Saccades Based on Cognitive Estimates of Remembered Vestibular Information

Author(s):  
J. Bloomberg ◽  
G. Melvill Jones ◽  
B. Segal ◽  
S. McFarlane ◽  
J. Soul
1994 ◽  
Vol 6 (4) ◽  
pp. 400-411 ◽  
Author(s):  
Avishai Henik ◽  
Robert Rafal ◽  
Dell Rhodes

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.


2015 ◽  
Vol 14 (5) ◽  
pp. 578-583 ◽  
Author(s):  
Robert A. Hensbroek ◽  
Tom J. H. Ruigrok ◽  
Boeke J. van Beugen ◽  
Jun Maruta ◽  
John I. Simpson

2000 ◽  
Vol 10 (1) ◽  
pp. 7-15 ◽  
Author(s):  
Helen S. Cohen

The goal of this study was to determine if people use vestibular information to keep track of their positions while walking through a simple course. Subjects were normals and patients with chronic peripheral vestibulopathies – each of whom were tested once – and patients with acoustic neuromas tested pre- operatively and one and three weeks post-operatively. Subjects walked over a straight course, 7.62 m, with their eyes open and then with their eyes closed. The time needed for task performance, the forward distance subjects walked before veering, and the lateral distance subjects veered from the straight ahead were recorded. The angle of veering was then calculated. Normals were able to perform this task easily with eyes open or closed. With eyes closed pre-operative acoustic neuroma subjects walked significantly shorter distances before veering than normals but did not veer significantly more than normals or take longer than normals to perform the task. Chronic vestibulopathy subjects, by contrast, were significantly impaired compared to normals on all measures. With eyes open within a week after acoustic neuroma resection subjects could perform the task as well as normals. With eyes closed, however, post-operative subjects were impaired compared to their own pre-operative levels, but they had returned to their pre-operative levels at the second post-operative test. Ataxia was only weakly correlated to any measures and tumor size was not related to performance. These findings support the hypothesis that vestibular input is used for spatial orientation during active motion.


1995 ◽  
Vol 74 (6) ◽  
pp. 2744-2748 ◽  
Author(s):  
E. C. Dias ◽  
M. Kiesau ◽  
M. A. Segraves

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.


2019 ◽  
Vol 16 (5) ◽  
pp. 558-571
Author(s):  
A. V. Belyakova ◽  
B. V. Saveliev

Introduction. Organization of high-quality training of the vehicles’ drivers is possible only with the proper formation of professional skills. Moreover, the formation of the skills is necessary for the driver to control the vehicle safety, perhaps by using simulators at the initial stage of training. The use of simulators allows automating the actions that the driver performs, while not exposing the student to risks.Therefore, the purpose of the paper is to analyze the application of simulators in the training of the vehicles’ drivers.Materials and methods. The paper presented the basic psycho physiological principles of the learning process, which should be taken into account when using simulators for driver training. The authors demonstrated the classification of the car simulators used for training of drivers by the information models. Existing information models of simulators were divided into two groups: reproducing only visual information, without imitation of the vestibular and simulating both visual and vestibular information. The analysis reflected the advantages and disadvantages of information models.Results. As a result, the authors proposed two systematizing features: the view angle of the visual information and the simulation of vestibular information.Discussion and conclusions. The research is useful not only for the further science development, but also for the selection of simulators and for the organization of the educational process in driving schools.


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