scholarly journals Eye Velocity Gain Fields in MSTd During Optokinetic Stimulation

2014 ◽  
Vol 25 (8) ◽  
pp. 2181-2190 ◽  
Author(s):  
Lukas Brostek ◽  
Ulrich Büttner ◽  
Michael J. Mustari ◽  
Stefan Glasauer
Keyword(s):  
Optokinetic Stimulation ◽  
Velocity Gain ◽  
Eye Velocity

scholarly journals Negative optokinetic afternystagmus in larval zebrafish demonstrates set-point adaptation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ting-Feng Lin ◽  
Mohammad Mohammadi ◽  
Ahmed M. Fathalla ◽  
Duygu Pul ◽  
Dennis Lüthi ◽  
...  
Keyword(s):  
Motor Learning ◽  
Light Extinction ◽  
Slow Phase ◽  
Optokinetic Stimulation ◽  
Zebrafish Model ◽  
Set Point ◽  
Larval Zebrafish ◽  
Optokinetic Afternystagmus ◽  
Sensorimotor Memory ◽  
Eye Velocity

AbstractMotor learning is essential to maintain accurate behavioral responses. We used a larval zebrafish model to study ocular motor learning behaviors. During a sustained period of optokinetic stimulation in 5-day-old wild-type zebrafish larvae the slow-phase eye velocity decreased over time. Then interestingly, a long-lasting and robust negative optokinetic afternystagmus (OKAN) was evoked upon light extinction. The slow-phase velocity, the quick-phase frequency, and the decay time constant of the negative OKAN were dependent on the stimulus duration and the adaptation to the preceding optokinetic stimulation. Based on these results, we propose a sensory adaptation process during continued optokinetic stimulation, which, when the stimulus is removed, leads to a negative OKAN as the result of a changed retinal slip velocity set point, and thus, a sensorimotor memory. The pronounced negative OKAN in larval zebrafish not only provides a practical solution to the hitherto unsolved problems of observing negative OKAN, but also, and most importantly, can be readily applied as a powerful model for studying sensorimotor learning and memory in vertebrates.

scholarly journals Heading detection using motion templates and eye velocity gain fields

1998 ◽  
Vol 38 (14) ◽  
pp. 2155-2179 ◽  
Author(s):  
Jaap A. Beintema ◽  
A.V. van den Berg
Keyword(s):  
Velocity Gain ◽  
Eye Velocity

scholarly journals The transfer function of the rhesus macaque oculomotor system for small-amplitude slow motion trajectories

2018 ◽  
Author(s):  
Julianne Skinner ◽  
Antimo Buonocore ◽  
Ziad M. Hafed
Keyword(s):  
Eye Movements ◽  
Transfer Function ◽  
Rhesus Macaque ◽  
Large Amplitude ◽  
Small Amplitude ◽  
Temporal Frequency ◽  
Oculomotor System ◽  
Target Motion ◽  
Velocity Gain ◽  
Eye Velocity

AbstractTwo main types of small eye movements occur during gaze fixation: microsaccades and slow ocular drifts. While microsaccade generation has been relatively well-studied, ocular drift control mechanisms are unknown. Here we explored the degree to which monkey smooth eye movements, on the velocity scale of slow ocular drifts, can be generated systematically. Two male rhesus macaque monkeys tracked a spot moving sinusoidally, but slowly, along the horizontal or vertical directions. Maximum target displacement in the motion trajectory was 30 min arc (0.5 deg), and we varied the temporal frequency of target motion from 0.2 to 5 Hz. We obtained an oculomotor “transfer function” by measuring smooth eye velocity gain (relative to target velocity) as a function of frequency, similar to past work with large-amplitude pursuit. Monkey eye velocities as slow as those observed during slow ocular drifts were clearly target-motion driven. Moreover, like with large-amplitude smooth pursuit, eye velocity gain varied with temporal frequency. However, unlike with large-amplitude pursuit, exhibiting low-pass behavior, small-amplitude motion tracking was band-pass with the best ocular movement gain occurring at ~0.8-1 Hz. When oblique directions were tested, we found that the horizontal component of pursuit gain was larger than the vertical component. Our results provide a catalogue of the control abilities of the monkey oculomotor system for slow target motions, and they also support the notion that smooth fixational ocular drifts are controllable. This has implications for neural investigations of drift control and the image-motion consequences of drifts on visual coding in early visual areas.

Neuronal Substrates of Motor Learning in the Velocity Storage Generated During Optokinetic Stimulation in the Squirrel Monkey

2007 ◽  
Vol 97 (2) ◽  
pp. 1114-1126 ◽  
Author(s):  
Pablo M. Blazquez ◽  
Maria A. Davis-Lopez de Carrizosa ◽  
Shane A. Heiney ◽  
Stephen M. Highstein
Keyword(s):  
Motor Learning ◽  
Brain Stem ◽  
High Gain ◽  
Velocity Storage ◽  
Optokinetic Stimulation ◽  
Optokinetic Response ◽  
Head Velocity ◽  
Velocity Sensitivity ◽  
Before And After ◽  
Eye Velocity

Chronic motor learning in the vestibuloocular reflex (VOR) results in changes in the gain of this reflex and in other eye movements intimately associated with VOR behavior, e.g., the velocity storage generated by optokinetic stimulation (OKN velocity storage). The aim of the present study was to identify the plastic sites responsible for the change in OKN velocity storage after chronic VOR motor learning. We studied the neuronal responses of vertical eye movement flocculus target neurons (FTNs) during the optokinetic afternystagmus (OKAN) phase of the optokinetic response (OKR) before and after VOR motor learning. Our findings can be summarized as follows. 1) Chronic VOR motor learning changes the horizontal OKN velocity storage in parallel with changes in VOR gain, whereas the vertical OKN velocity storage is more complex, increasing with VOR gain increases, but not changing following VOR gain decreases. 2) FTNs contain an OKAN signal having opposite directional preferences after chronic high versus low gain learning, suggesting a change in the OKN velocity storage representation of FTNs. 3) Changes in the eye-velocity sensitivity of FTNs during OKAN are correlated with changes in the brain stem head-velocity sensitivity of the same neurons. And 4) these changes in eye-velocity sensitivity of FTNs during OKAN support the new behavior after high gain but not low gain learning. Thus we hypothesize that the changes observed in the OKN velocity storage behavior after chronic learning result from changes in brain stem pathways carrying head velocity and OKN velocity storage information, and that a parallel pathway to vertical FTNs changes its OKN velocity storage representation following low, but not high, gain VOR motor learning.

Preliminary Evaluation of a Weibull Function for Fitting Slow-Component Eye Velocity over the Time Course of Caloric-Induced Nystagmus

1989 ◽  
Vol 32 (3) ◽  
pp. 681-687 ◽  
Author(s):  
C. Formby ◽  
B. Albritton ◽  
I. M. Rivera
Keyword(s):  
Time Course ◽  
Slow Component ◽  
Weibull Function ◽  
Preliminary Evaluation ◽  
Mathematical Function ◽  
Before And After ◽  
Best Fitting ◽  
Eye Velocity ◽  
Fitting Parameters ◽  
Weibull Equation

We describe preliminary attempts to fit a mathematical function to the slow-component eye velocity (SCV) over the time course of caloric-induced nystagmus. Initially, we consider a Weibull equation with three parameters. These parameters are estimated by a least-squares procedure to fit digitized SCV data. We present examples of SCV data and fitted curves to show how adjustments in the parameters of the model affect the fitted curve. The best fitting parameters are presented for curves fit to 120 warm caloric responses. The fitting parameters and the efficacy of the fitted curves are compared before and after the SCV data were smoothed to reduce response variability. We also consider a more flexible four-parameter Weibull equation that, for 98% of the smoothed caloric responses, yields fits that describe the data more precisely than a line through the mean. Finally, we consider advantages and problems in fitting the Weibull function to caloric data.

Existence in the nucleus incertus of the cat of horizontal-eye-movement-related neurons projecting to the cerebellar flocculus

1995 ◽  
Vol 74 (3) ◽  
pp. 1367-1372 ◽  
Author(s):  
G. Cheron ◽  
S. Saussez ◽  
N. Gerrits ◽  
E. Godaux
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Retrograde Transport ◽  
Great Sensitivity ◽  
Antidromic Activation ◽  
Vertical Movements ◽  
Cerebellar Flocculus ◽  
Nucleus Incertus ◽  
Alert Cats ◽  
Eye Velocity

1. Properties of nucleus incertus (NIC) neurons projecting to the cerebellar flocculus were studied in alert cats by using chronic unit and eye movement recording and antidromic activation. Projection of these neurons onto the flocculus was verified with retrograde transport of horseradish peroxidase after injections in the flocculus. 2. Bipolar stimulation electrodes were implanted into the "middle" zone of each flocculus because this zone is known to be involved in the control of horizontal eye movements. The dorsomedial aspect of the pontine tegmentum was explored with microelectrodes during stimulation of both flocculi. The majority of neurons antidromically activated from the flocculus were found in the caudal part of the NIC. 3. Of the 69 neurons activated from the flocculus, 44 were classified as burst-tonic (BT) neurons; 34 discharged in relation with horizontal movements of the eye, 10 in relation with vertical movements. Of the 14 remaining neurons, 6 were not related to eye movements and 8 were classified as burst neurons. The BT neurons of the NIC displayed a great sensitivity to both horizontal eye position and horizontal eye velocity. 4. This study demonstrates the presence of a new group of horizontal eye movement related BT neurons situated in the NIC. The fact that they project to the horizontal floccular zone emphasizes the importance of the functional specialization of the different Purkinje cell zones.

Visually evoked slow eye movements, visual-vestibular interaction, and infratentorial lesions

1983 ◽  
Vol 91 (1) ◽  
pp. 76-80 ◽  
Author(s):  
Carsten Wennmo ◽  
Nils Gunnar Henriksson ◽  
Bengt Hindfelt ◽  
Ilmari PyykkÖ ◽  
MÅNs Magnusson
Keyword(s):  
Eye Movements ◽  
Phase Velocity ◽  
Brain Stem ◽  
Smooth Pursuit ◽  
Maximum Velocity ◽  
Slow Phase ◽  
Slow Phase Velocity ◽  
Velocity Gain ◽  
Visual Vestibular Interaction ◽  
Slow Eye Movements

The maximum velocity gain of smooth pursuit and optokinetic, vestibular, and optovestibular slow phases was examined in 15 patients with pontine, 10 with medullary, 10 with cerebellar, and 5 with combined cerebello — brain stem disorders. Marked dissociations were observed between smooth pursuit and optokinetic slow phases, especially in medullary disease. A cerebellar deficit enhanced slow phase velocity gain during rotation in darkness, whereas the corresponding gain during rotation in light was normal.

scholarly journals Motion Sickness and Migraine: Optokinetic Stimulation Increases Scalp Tenderness, Pain Sensitivity in the Fingers and Photophobia

Cephalalgia ◽  
2002 ◽  
Vol 22 (2) ◽  
pp. 117-124 ◽  
Author(s):  
PD Drummond
Keyword(s):  
Motion Sickness ◽  
Pain Sensitivity ◽  
Pain Perception ◽  
Optokinetic Stimulation ◽  
Nociceptive Pathways ◽  
General Influence

The aim of this study was to determine whether scalp tenderness and photophobia, two well-recognized symptoms of migraine, develop during the motion sickness induced by optokinetic stimulation. To investigate whether motion sickness has a general influence on pain perception, pain was also assessed in the fingertips. After optokinetic stimulation, nausea increased more and headache persisted longer in 21 migraine sufferers than in 15 non-headache controls. Scalp tenderness increased during optokinetic stimulation in nauseated subjects, and pain in the fingertips increased more and photophobia persisted longer in migraine sufferers than controls. These findings suggest that the disturbance responsible for nausea also sensitizes trigeminal nociceptive neurones or releases inhibitory controls on their discharge. A low nausea threshold and a propensity for sensitization to develop rapidly in nociceptive pathways may increase susceptibility to migraine.

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