scholarly journals Effects of lorazepam on saccadic eye movements: the role of sex, task characteristics and baseline traits

2018 ◽  
Vol 32 (6) ◽  
pp. 678-690 ◽  
Author(s):  
Ulrich Ettinger ◽  
Inga Meyhöfer ◽  
Mitul A Mehta ◽  
Veena Kumari ◽  
Philip J Corr ◽  
...  
Keyword(s):  
Eye Movements ◽  
Peak Velocity ◽  
Drug Effects ◽  
Saccadic Eye Movements ◽  
Task Characteristics ◽  
Double Blind ◽  
Spatial Consistency ◽  
Within Subjects ◽  
Dose Dependent

Background: Saccadic eye movements are controlled by a network of parietal, frontal, striatal, cerebellar and brainstem regions. The saccadic peak velocity is an established biomarker of benzodiazepine effects, with benzodiazepines reliably reducing the peak velocity. Aims: In this study, we aimed to replicate the effects of benzodiazepines on peak velocity and we investigated effects on previously less studied measures of saccades. We also explored the roles of sex, task characteristics and the baseline variables age, intelligence and trait anxiety in these effects. Method: Healthy adults ( N = 34) performed a horizontal step prosaccade task under 1 mg lorazepam, 2 mg lorazepam and placebo in a double-blind, within-subjects design. Results: We replicated the dose-dependent reduction in peak velocity with lorazepam and showed that this effect is stronger for saccades to targets at smaller eccentricities. We also demonstrated that this effect is independent of sex and other baseline variables. Lorazepam effects were widespread, however, occurring on mean and variability measures of most saccadic variables. Additionally, there were sex-dependent lorazepam effects on spatial consistency of saccades, indicating more adverse effects in females. Conclusions: We conclude that saccadic peak velocity is a sensitive and robust biomarker of benzodiazepine effects. However, lorazepam has pronounced effects also on other parameters of horizontal saccades. Sex-dependent drug effects on spatial consistency may reflect cerebellar mechanisms, given the role of the cerebellum in saccadic spatial accuracy.

Effects of lorazepam on prosaccades and saccadic adaptation

2020 ◽  
Vol 35 (1) ◽  
pp. 91-99
Author(s):  
Katharina Bey ◽  
Julia V Lippold ◽  
Behrem Aslan ◽  
René Hurlemann ◽  
Ulrich Ettinger
Keyword(s):  
Adverse Effects ◽  
Peak Velocity ◽  
Saccadic Eye Movements ◽  
Learning Gain ◽  
Double Blind ◽  
Saccadic Adaptation ◽  
Spatial Consistency ◽  
Within Subjects ◽  
The Impact

Background: Benzodiazepines have reliable adverse effects on saccadic eye movements, but the impact of sex as a potential modulator of these effects is less clear. A recent study reported stronger adverse effects on the spatial consistency of saccades in females, which may reflect sex differences in cerebellar mechanisms. Aims: We aimed to further examine the role of sex as a potential modulator of benzodiazepine effects by employing the saccadic adaptation paradigm, which is known to be sensitive to cerebellar functioning. Methods: A total of n=50 healthy adults performed a horizontal step prosaccade task and a saccadic adaptation task under 0.5 mg lorazepam, 1 mg lorazepam and placebo in a double-blind, within-subjects design. Results: In the prosaccade task, lorazepam had adverse effects on measures of peak velocity, latency and spatial consistency. The administration of 0.5 mg lorazepam led to significant reductions in gain-decrease adaptation, while a dose of 1 mg did not impair adaptation learning. Gain-increase adaptation was generally less pronounced, and unaffected by the drug. There were no significant drug×sex interactions in either task. Conclusions: We conclude that a low dose of lorazepam impairs gain-decrease adaptation independent of sex. At higher doses, however, increasing fatigue may facilitate adaptation and thus counteract the adverse effects observed at lower doses. With regards to prosaccades, our findings confirm peak velocity as well as latency and spatial measures as sensitive biomarkers of GABAergic effects.

scholarly journals The role of action intentionality and effector in the subjective expansion of temporal duration after saccadic eye movements

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
David Melcher ◽  
Devpriya Kumar ◽  
Narayanan Srinivasan
Keyword(s):  
Eye Movements ◽  
Visual Processing ◽  
Saccadic Eye Movements ◽  
Intentional Binding ◽  
Opposite Pattern ◽  
Motor Action ◽  
Saccade Onset ◽  
Backward Shift ◽  
The Moment

Abstract Visual perception is based on periods of stable fixation separated by saccadic eye movements. Although naive perception seems stable (in space) and continuous (in time), laboratory studies have demonstrated that events presented around the time of saccades are misperceived spatially and temporally. Saccadic chronostasis, the “stopped clock illusion”, represents one such temporal distortion in which the movement of the clock hand after the saccade is perceived as lasting longer than usual. Multiple explanations for chronostasis have been proposed including action-backdating, temporal binding of the action towards the moment of its effect (“intentional binding”) and post-saccadic temporal dilation. The current study aimed to resolve this debate by using different types of action (keypress vs saccade) and varying the intentionality of the action. We measured both perceived onset of the motor action and perceived onset of an auditory tone presented at different delays after the keypress/saccade. The results showed intentional binding for the keypress action, with perceived motor onset shifted forwards in time and the time of the tone shifted backwards. Saccades resulted in the opposite pattern, showing temporal expansion rather than compression, especially with cued saccades. The temporal illusion was modulated by intentionality of the movement. Our findings suggest that saccadic chronostasis is not solely dependent on a backward shift in perceived saccade onset, but instead reflects a temporal dilation. This percept of an effectively “longer” period at the beginning of a new fixation may reflect the pattern of suppressed, and then enhanced, visual processing around the time of saccades.

scholarly journals The role of fixation disengagement in the parallel programming of sequences of saccades

2019 ◽  
Vol 237 (11) ◽  
pp. 3033-3045
Author(s):  
Eugene McSorley ◽  
Iain D. Gilchrist ◽  
Rachel McCloy
Keyword(s):  
Eye Movements ◽  
Parallel Programming ◽  
Response Times ◽  
Saccadic Eye Movements ◽  
Gap Effect ◽  
Task Completion ◽  
Published Data ◽  
Trial Duration ◽  
Visual Tasks

Abstract One of the core mechanisms involved in the control of saccade responses to selected target stimuli is the disengagement from the current fixation location, so that the next saccade can be executed. To carry out everyday visual tasks, we make multiple eye movements that can be programmed in parallel. However, the role of disengagement in the parallel programming of saccades has not been examined. It is well established that the need for disengagement slows down saccadic response time. This may be important in allowing the system to program accurate eye movements and have a role to play in the control of multiple eye movements but as yet this remains untested. Here, we report two experiments that seek to examine whether fixation disengagement reduces saccade latencies when the task completion demands multiple saccade responses. A saccade contingent paradigm was employed and participants were asked to execute saccadic eye movements to a series of seven targets while manipulating when these targets were shown. This both promotes fixation disengagement and controls the extent that parallel programming can occur. We found that trial duration decreased as more targets were made available prior to fixation: this was a result both of a reduction in the number of saccades being executed and in their saccade latencies. This supports the view that even when fixation disengagement is not required, parallel programming of multiple sequential saccadic eye movements is still present. By comparison with previous published data, we demonstrate a substantial speeded of response times in these condition (“a gap effect”) and that parallel programming is attenuated in these conditions.

Visual Fatigue and Saccadic Eye Movement Parameters

1983 ◽  
Vol 27 (8) ◽  
pp. 728-732 ◽  
Author(s):  
Ted Megaw ◽  
Tayyar Sen
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Peak Velocity ◽  
Cognitive Task ◽  
Saccadic Eye Movements ◽  
Tracking Task ◽  
Frequency Of Occurrence ◽  
Saccadic Eye Movement ◽  
Visual Fatigue ◽  
Movement Parameters

It has been suggested by Bahill and Stark (1975) that visual fatigue can be identified by changes in some of the saccadic eye movement parameters. These include increases in the frequency of occurrence of glissades and overlapping saccades and reductions in the peak velocity and duration of saccades. In their study, fatigue was induced by the same step tracking task that was used to evaluate the changes in saccadic parameters. However, there is evidence that subjects experience extreme feelings of fatigue while performing such a task and that somehow the task is unnatural. The present study was designed to assess whether there are any differences in the various saccadic parameters obtained while subjects perform a step tracking task and a cognitive task involving the comparison of number strings. Both tasks were presented on a VDU screen. The second objective was to establish whether there are any changes in the parameters for either task as a result of prolonged performance. The results showed no major differences in the saccadic eye movements between the two tasks and no consistent changes resulting from prolonged performance.

Role of Saccadic Eye Movements in Cognitive Processes

2009 ◽  
Vol 147 (1) ◽  
pp. 11-14
Author(s):  
N. A. Ryabchikova ◽  
B. H. Bazyian ◽  
V. B. Poliansky ◽  
O. A. Pletnev
Keyword(s):  
Eye Movements ◽  
Cognitive Processes ◽  
Saccadic Eye Movements

5. Role of the amygdala in the control of saccadic eye movements

2008 ◽  
Vol 119 (9) ◽  
pp. e166
Author(s):  
S.L. Gonzalez Andino ◽  
C. Laine ◽  
R. Grave de Peralta ◽  
K.L. Gothard
Keyword(s):  
Eye Movements ◽  
Saccadic Eye Movements

Role of cat pontine burst neurons in generation of saccadic eye movements.

1981 ◽  
Vol 46 (3) ◽  
pp. 387-408 ◽  
Author(s):  
C R Kaneko ◽  
C Evinger ◽  
A F Fuchs
Keyword(s):  
Eye Movements ◽  
Saccadic Eye Movements ◽  
Burst Neurons

Role of vestibular adaptation in vestibular rehabilitation

1998 ◽  
Vol 119 (1) ◽  
pp. 49-54 ◽  
Author(s):  
Susan J. Herdman
Keyword(s):  
Eye Movements ◽  
Postural Stability ◽  
Saccadic Eye Movements ◽  
Human Beings ◽  
Compensatory Mechanisms ◽  
Ocular Reflex ◽  
Reflex Modification ◽  
Postural Responses ◽  
Vestibular Cues

Recovery of gaze and postural stability in human beings with vestibular deficits is well documented. The mechanisms that contribute to this recovery form the basis for the exercises used in the rehabilitation of these patients. These mechanisms include the central preprogramming of eye movements and of postural responses, the potentiation of the cervico-ocular reflex, modification of saccadic eye movements, and the substitution of visual and somatosensory cues for the lost vestibular cues. The mechanism most successful in contributing to recovery, however, is probably adaptation of the vestibular system itself. Understanding the various compensatory mechanisms and their limitations for improving gaze and postural stability should lead to more effective treatment of these patients. (Otolaryngol Head Neck Surg 1998;119:49–54.)

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