scholarly journals Spinocerebellar degeneration and slow saccades in three generations of a kinship: clinical and electrophysiologic findings

1984 ◽  
Vol 42 (3) ◽  
pp. 232-241 ◽  
Author(s):  
Enaytolah Niakan ◽  
Tulio E. Bertorini ◽  
Helio Lemmi ◽  
Milton Medeiros ◽  
Richard Drewry ◽  
...  
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Reticular Formation ◽  
Rem Sleep ◽  
Saccadic Eye Movements ◽  
Saccadic Eye Movement ◽  
Spinocerebellar Degeneration ◽  
Rapid Eye Movements ◽  
Electrophysiological Studies ◽  
Slow Saccades

Four members of a family with spinocerebellar degeneration and slow saccadic eye movements are described. Detailed electrophysiological studies revealed abnormalities of neurological pathways not apparent clinically. The patients had slow saccades as mesasured electrophysiologically, as well as absence of rapid eye movements (REM) despite REM stages of sleep. These studies suggest that although saccadic eye movement and REM are mediated through the pontine paramedian reticular formation, other characteristics of REM sleep are not necessarily mediated through the same neurons.

Phantom array and stroboscopic effects of a time-modulated moving light source during saccadic eye movement

2017 ◽  
Vol 50 (5) ◽  
pp. 772-786 ◽  
Author(s):  
C-S Lee ◽  
J-H Lee ◽  
H Pak ◽  
SW Park ◽  
D-W Song
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Light Source ◽  
Light Emitting Diode ◽  
Saccadic Eye Movements ◽  
Movement Speed ◽  
Light Sources ◽  
Saccadic Eye Movement ◽  
Modulated Light ◽  
Source Motion

This paper evaluates the detectability of the phantom array and stroboscopic effects during light source motion, eye movement and their combination, using time modulated light-emitting diode light sources. It is well known that the phantom array can be observed when time-modulated light sources are observed during saccadic eye movements. We investigated whether light source motion can cause similar effects when the subject has fixed eyes. In addition, we estimated the detectability threshold frequency for the combination of stroboscopic effect and the phantom array, which is named the stroboscopic-phantom array effect, during two eye movements in opposite directions under one directional rotating light source with variable speed. Our results indicate that one of the most important factors for the stroboscopic-phantom array effect is eye movement speed relative to the speed of the light source. Therefore, time-modulated moving light sources induce a stroboscopic effect in subjects with fixed eyes that is similar to the stroboscopic-phantom array effect observed during saccadic eye movement. Our findings are likely to be useful for predicting the stroboscopic effect and the stroboscopic-phantom array effect during the fast motion of time-modulated LED light sources, like multi-functional rear lamps, in automotive lighting applications.

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.

Sleep-Related Electrophysiology and Behavior of Tinamous (Eudromia elegans): Tinamous Do Not Sleep Like Ostriches

2017 ◽  
Vol 89 (4) ◽  
pp. 249-261 ◽  
Author(s):  
Ryan K. Tisdale ◽  
Alexei L. Vyssotski ◽  
John A. Lesku ◽  
Niels C. Rattenborg
Keyword(s):  
Eye Movements ◽  
Rem Sleep ◽  
Slow Wave Sleep ◽  
Muscle Tone ◽  
Slow Waves ◽  
Sleep State ◽  
Rapid Eye Movements ◽  
Electrophysiological Studies ◽  
Taxonomic Groups ◽  
And Behavior

The functions of slow wave sleep (SWS) and rapid eye movement (REM) sleep, distinct sleep substates present in both mammals and birds, remain unresolved. One approach to gaining insight into their function is to trace the evolution of these states through examining sleep in as many taxonomic groups as possible. The mammalian and avian clades are each composed of two extant groups, i.e., the monotremes (echidna and platypus) and therian (marsupial and eutherian [or placental]) mammals, and Palaeognaths (cassowaries, emus, kiwi, ostriches, rheas, and tinamous) and Neognaths (all other birds) among birds. Previous electrophysiological studies of monotremes and ostriches have identified a unique “mixed” sleep state combining features of SWS and REM sleep unlike the well-delineated sleep states observed in all therian mammals and Neognath birds. In the platypus this state is characterized by periods of REM sleep-related myoclonic twitching, relaxed skeletal musculature, and rapid eye movements, occurring in conjunction with SWS-related slow waves in the forebrain electroencephalogram (EEG). A similar mixed state was also observed in ostriches; although in addition to occurring during periods with EEG slow waves, reduced muscle tone and rapid eye movements also occurred in conjunction with EEG activation, a pattern typical of REM sleep in Neognath birds. Collectively, these studies suggested that REM sleep occurring exclusively as an integrated state with forebrain activation might have evolved independently in the therian and Neognath lineages. To test this hypothesis, we examined sleep in the elegant crested tinamou (Eudromia elegans), a small Palaeognath bird that more closely resembles Neognath birds in size and their ability to fly. A 24-h period was scored for sleep state based on electrophysiology and behavior. Unlike ostriches, but like all of the Neognath birds examined, all indicators of REM sleep usually occurred in conjunction with forebrain activation in tinamous. The absence of a mixed REM sleep state in tinamous calls into question the idea that this state is primitive among Palaeognath birds and therefore birds in general.

scholarly journals Saccadic Eye Movements as a Marker of Mental Disorders

2016 ◽  
pp. S365-S371 ◽  
Author(s):  
F. JAGLA
Keyword(s):  
Eye Movements ◽  
Mental Disorders ◽  
Eye Movement ◽  
Saccadic Eye Movements ◽  
Motor Program ◽  
Biologically Active ◽  
Saccadic Eye Movement ◽  
Analytical Processing ◽  
Short Comment ◽  
The Brain

It is accepted that the formulation of the motor program in the brain is not only the perceptual and motor function but also the cognitive one. Therefore it is not surprising that the execution of saccadic eye movements can by substantially affected be the on-going mental activity of a given person. Not only the distribution of attention, but also the focusing the attention may influence the main gain of saccades, their accuracy. Patients suffering from mental disorders have strongly engaged their attention focused at their mental processes. The nature of their problems may be linked to perceptual and/or analytical processing. Such so-called mental set may significantly affect their oculomotor activity in the course of their saccadic eye movement examinations. This short comment points out not only to the influence of the contextually guided and generated saccadic eye movements upon their accuracy but also to the distribution and focusing the attention. The effect of the functional brain asymmetry upon the visually generated saccades and the possible effect of biologically active substances upon the voluntary generated saccades are briefly mentioned. All these influences should be taken into account when planning the saccadic eye movement task. It may be concluded that the repetition of the same oculomotor task in a given person has to be introduced. This may help to follow the effect of complex therapy namely.

scholarly journals Polar-angle representation of saccadic eye movements in human superior colliculus

2017 ◽  
Author(s):  
Ricky R Savjani ◽  
Elizabeth Halfen ◽  
Jung Hwan Kim ◽  
David Ress
Keyword(s):  
Eye Movements ◽  
Superior Colliculus ◽  
Eye Movement ◽  
Visual Stimulation ◽  
Polar Angle ◽  
Saccadic Eye Movements ◽  
List Type ◽  
Saccadic Eye Movement ◽  
Intermediate Layers ◽  
Retinotopic Organization

SummaryThe superior colliculus (SC) is a layered midbrain structure involved in directing eye movements and coordinating visual attention. Electrical stimulation and neuronal recordings in the intermediate layers of monkey SC have shown a retinotopic organization for the mediation of saccadic eye-movements. However, in human SC the topography of saccades is unknown. Here, a novel experimental paradigm and highresolution (1.2-mm) functional magnetic resonance imaging methods were used to measure activity evoked by saccadic eye movements within SC. Results provide three critical observations about the topography of the human SC: (1) saccades along the superior-inferior visual axis are mapped across the medial-lateral anatomy of the SC; (2) the saccadic eye-movement representation is in register with the retinotopic organization of visual stimulation; and (3) activity evoked by saccades occurs deeper within SC than that evoked by visual stimulation. These approaches lay the foundation for studying the organization of human subcortical eye-movement mechanisms.HighlightsHigh-resolution functional MRI enabled imaging from intermediate layers of human SCSaccades along superior-inferior visual field are mapped across medial-lateral SCSaccadic eye movement maps lie deeper in SC and are in alignment with retinotopyeTOC BlurbSavjani et al. found the polar angle representation of saccadic eye movements in human SC. The topography is similar in monkey SC, is in register with the retinotopic organization evoked by visual stimulation, but lies within deeper layers. These methods enable investigation of human subcortical eye-movement organization and visual function.

Is Target Movement as Well as Target Displacement a Stimulus for Saccadic Eye Movements?

Perception ◽  
1983 ◽  
Vol 12 (1) ◽  
pp. 35-41
Author(s):  
John M Findlay ◽  
Lucia Zanuttini
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Line Segment ◽  
Apparent Movement ◽  
Saccadic Eye Movements ◽  
Saccadic Eye Movement ◽  
Target Movement ◽  
Line Segments ◽  
Visual Movement

The effects of visual movement on saccadic eye movement have been examined. In a classic apparent-movement demonstration with two successively exposed line-segment targets the quality of the movement is dependent on the relative orientation of the line segments. If saccadic eye movements are elicited between the targets in this situation, the configuration leading to optimal apparent movement also leads to the shortest-latency saccades. When a single line segment is succeeded by two line segments flanking it on opposite sides, and if one of these has the same orientation as the initial one and the other a different orientation, then apparent motion is seen between the two lines with the same orientation. However, the direction of saccades elicited in this configuration is not influenced by the relative orientations of the line segments. The two results together suggest that the effect of visual movement on saccadic eye movement is nonspecific.

scholarly journals Regional low-frequency oscillations in human rapid-eye movement sleep

2018 ◽  
Author(s):  
Giulio Bernardi ◽  
Monica Betta ◽  
Emiliano Ricciardi ◽  
Pietro Pietrini ◽  
Giulio Tononi ◽  
...  
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Rem Sleep ◽  
Low Frequency ◽  
Nrem Sleep ◽  
Slow Waves ◽  
Gamma Activity ◽  
Rapid Eye Movement ◽  
Rapid Eye Movements ◽  
Low Frequency Oscillations

AbstractAlthough the EEG slow wave of sleep is typically considered to be a hallmark of Non Rapid Eye Movement (NREM) sleep, recent work in mice has shown that slow waves can also occur in REM sleep. Here we investigated the presence and cortical distribution of low-frequency (1-4 Hz) oscillations in human REM sleep by analyzing high-density EEG sleep recordings obtained in 28 healthy subjects. We identified two clusters of low-frequency oscillations with distinctive properties: 1) a fronto-central cluster characterized by ∼2.5-3.0 Hz, relatively large, notched delta waves (so-called ‘sawtooth waves’) that tended to occur in bursts, were associated with increased gamma activity and rapid eye movements, and upon source modeling, displayed an occipito-temporal and a fronto-central component; and 2) a medial occipital cluster characterized by more isolated, slower (<2 Hz) and smaller waves that were not associated with rapid eye movements, displayed a negative correlation with gamma activity and were also found in NREM sleep. Thus, low-frequency oscillations are an integral part of REM sleep in humans, and the two identified subtypes (sawtooth and medial-occipital slow waves) may reflect distinct generation mechanisms and functional roles. Sawtooth waves, which are exclusive to REM sleep, share many characteristics with ponto-geniculo-occipital (PGO) waves described in animals and may represent the human equivalent or a closely related event while medio-occipital slow waves appear similar to NREM sleep slow waves.

scholarly journals Macaque Pontine Omnipause Neurons Play No Direct Role in the Generation of Eye Blinks

2010 ◽  
Vol 103 (4) ◽  
pp. 2255-2274 ◽  
Author(s):  
K. P. Schultz ◽  
C. R. Williams ◽  
C. Busettini
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Time Constant ◽  
Dynamic Change ◽  
Saccadic Eye Movements ◽  
Oscillatory Behavior ◽  
Saccadic Eye Movement ◽  
Direct Role ◽  
Eye Blinks ◽  
Omnipause Neurons

We recorded the activity of pontine omnipause neurons (OPNs) in two macaques during saccadic eye movements and blinks. As previously reported, we found that OPNs fire tonically during fixation and pause about 15 ms before a saccadic eye movement. In contrast, for blinks elicited by air puffs, the OPNs paused <2 ms before the onset of the blink. Thus the burst in the agonist orbicularis oculi motoneurons (OOMNs) and the pause in the antagonist levator palpabrae superioris motoneurons (LPSMNs) necessarily precede the OPN pause. For spontaneous blinks there was no correlation between blink and pause onsets. In addition, the OPN pause continued for 40–60 ms after the time of the maximum downward closing of the eyelids, which occurs around the end of the OOMN burst of firing. LPSMN activity is not responsible for terminating the OPN pause because OPN resumption was very rapid, whereas the resumption of LPSMN firing during the reopening phase is gradual. OPN pause onset does not directly control blink onset, nor does pause offset control or encode the transition between the end of the OOMN firing and the resumption of the LPSMNs. The onset of the blink-related eye transients preceded both blink and OPN pause onsets. Therefore they initiated while the saccadic short-lead burst neurons were still fully inhibited by the OPNs and cannot be saccadic in origin. The abrupt dynamic change of the vertical eye transients from an oscillatory behavior to a single time constant exponential drift predicted the resumption of the OPNs.

REM sleep burst neurons, PGO waves, and eye movement information

1983 ◽  
Vol 50 (4) ◽  
pp. 784-797 ◽  
Author(s):  
J. P. Nelson ◽  
R. W. McCarley ◽  
J. A. Hobson
Keyword(s):  
Eye Movements ◽  
Visual System ◽  
Eye Movement ◽  
Rem Sleep ◽  
Rapid Eye Movement Sleep ◽  
Generation System ◽  
Rapid Eye Movements ◽  
Midbrain Neurons ◽  
Burst Neuron ◽  
Pgo Waves

Pontogeniculooccipital (PGO) waves appeared almost simultaneously in both lateral geniculate nuclei (LGB), but in each case on had a larger amplitude and preceded the other by a few milliseconds. The larger, earlier wave is called the primary wave. Primary waves were found to appear with equal frequency in each LGB. During rapid eye movement sleep (REM sleep), LGB primary waves were ipsilateral to the direction of rapid eye movements. During REM sleep a group of cat midbrain neurons, which we call PGO burst cells, fired in stereotyped bursts at fixed latencies before ipsilateral primary waves, but they almost never fired bursts when the primary waves were contralateral. PGO burst neuron discharge also correlated with the direction of rapid eye movements during REM sleep. In wakefulness, PGO burst cells fired single spikes, not bursts, which had some correlation with LGB waves when averaged by computer. The results suggest that PGO burst cells are output elements in the PGO wave-generation system ad that PGO waves convey eye movement information to the sensory visual system in REM sleep. They also may have a role in the production of saccade-related waves in the visual system during wakefulness.

scholarly journals A Retinotopic Attentional Trace after Saccadic Eye Movements: Evidence from Event-related Potentials

2013 ◽  
Vol 25 (9) ◽  
pp. 1563-1577 ◽  
Author(s):  
Durk Talsma ◽  
Brian J. White ◽  
Sebastiaan Mathôt ◽  
Douglas P. Munoz ◽  
Jan Theeuwes
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Visual Stimulus ◽  
Saccadic Eye Movements ◽  
Event Related Potentials ◽  
Saccadic Eye Movement ◽  
Visual Stability ◽  
Specific Location ◽  
Related Potentials ◽  
Significant Attenuation

Saccadic eye movements are a major source of disruption to visual stability, yet we experience little of this disruption. We can keep track of the same object across multiple saccades. It is generally assumed that visual stability is due to the process of remapping, in which retinotopically organized maps are updated to compensate for the retinal shifts caused by eye movements. Recent behavioral and ERP evidence suggests that visual attention is also remapped, but that it may still leave a residual retinotopic trace immediately after a saccade. The current study was designed to further examine electrophysiological evidence for such a retinotopic trace by recording ERPs elicited by stimuli that were presented immediately after a saccade (80 msec SOA). Participants were required to maintain attention at a specific location (and to memorize this location) while making a saccadic eye movement. Immediately after the saccade, a visual stimulus was briefly presented at either the attended location (the same spatiotopic location), a location that matched the attended location retinotopically (the same retinotopic location), or one of two control locations. ERP data revealed an enhanced P1 amplitude for the stimulus presented at the retinotopically matched location, but a significant attenuation for probes presented at the original attended location. These results are consistent with the hypothesis that visuospatial attention lingers in retinotopic coordinates immediately following gaze shifts.

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