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At least 19 recordsLinked to original sources
PubMed1985

The influence of preexisting oscillations on the binocular optokinetic response.

Full-field binocular optokinetic responses were examined in patients with congenital nystagmus. If the stimulus moved in the same plane as the congenital nystagmus, a gaze-modulated response was recorded for both idiopathic and albino observers. When the congenital nystagmus was almost totally suppressed, neither a gaze-evoked nor a sawtooth response was seen. For stimulus movements in a plane orthogonal to the congenital nystagmus, normal sawtooth optokinetic responses were exhibited by both groups. Experimental evidence supports the hypothesis that the optokinetic response in the meridian of the spontaneous oscillation has been adapted.

Adult↗
PubMed1980

Firing characteristics of neurons mediating optokinetic responses to rat's vestibular neurons.

1) The responses of single units in the pretectum (Pt) and in the n. reticularis tegmenti pontis (NRTP) to constant velocity horizontal rotation (0.25--60 deg/s) of a large-field visual pattern were studied in immobilized, non-anesthetized DA-HAN rats. In addition, responses of Pt and NRTP neurons to pure vestibular stimuli (rotation in the dark) were studied. 2) Pt neurons showed seven response types to optokinetic stimulation (Table 1). The most frequent response (48%) consisted of a very rapid increase in firing to steady state on temporonasal motion stimulation of the contralateral eye; nasotemporal stimuli yielded no change in resting rate as did stimulation of the ipsilateral eye. The response maximum occurred at a retinal slip velocity of 1 deg/s. None of the Pt units tested responded to pure vestibular stimuli. 3) NRTP neurons - as Pt units - most frequently (43%) increased their discharge rate on temporonasal stimulation of the contralateral eye and maintained a constant resting rate during nasotemporal motion. Peak response amplitudes also occurred with retinal slip velocites of 1 deg/s. Contrary to the fast time-to-peak of the responses of Pt neurons NRTP units showed a slow rise in frequency of firing to peak response levels. 4) NRTP neurons responded to pure vestibular stimuli (horizontal angular acceleration in the dark). The vestibular responses were synergistic with those evoked in the same neurons by optokinetic stimuli. Thus, the most frequently encountered type of optokinetic response (s. above) showed a type II vestibular response. 5) Comp]arison of OKN and Vn optokinetic responses with those of Pt and NRTP suggests that the unidirectional-selective Pt and NRTP neurons are important links in the central optokinetic path. In addition, the NRTP may represent the site at which the retinal slip signal and the eye velocity signal converge. This convergence has been postulated in models of the system [12].

Animals↗
PubMed1997

The horizontal optokinetic response of the goldfish.

This report describes the dynamics of the horizontal optokinetic response of the goldfish, and compares them with those of other species. Eye rotational velocity in response to step and sinusoidal rotations of the visual surround was tested using goldfish that had both eyes free to view the surround and to rotate with it. The step response was tested by switching on a visual surround display that was rotating at constant velocity, and then switching off the display, leaving the goldfish in the dark. The step-onset response was characterized by rapid and gradual components; the latter rose with an almost linear trajectory for higher surround velocities. The response was more rapid at step-offset than at step-onset. The step-offset response overshot baseline eye velocity for most goldfish and was oscillatory for the others. The steady-state response increased with constant velocity surround rotation within the range +/- 40 deg/sec but saturated outside that range. Steady-state response gain was higher for nasally-directed that for temporally-directed surround rotations. The frequency response was essentially low-pass, with gain decreasing from about 0.9 and phase lag increasing from zero to 90 deg as surround rotational frequency increased from 0.01 to 3.0 Hz. Sinusoidal response gain decreased as a function of surround peak acceleration. The results indicate that the horizontal optokinetic response of the goldfish is nonlinear and resembles in many respects that of mammals. Models developed to simulate the dynamics of the optokinetic response of mammals can be applied to that of goldfish and reproduce its nonlinear features.

Animals↗
PubMed1989

The effect of serotonin and octopamine on the optokinetic response of the crab Leptograpsus variegatus.

A standard optokinetic response of the ipsilateral and contralateral (driven) eyes of the crab Leptograpsus variegatus to a sinusoidally oscillating striped drum was established. Optokinetic responses were then measured of animals that had been treated by introducing serotonin and octopamine into the blood stream via the heart and also into the neural tissue of the optic lobes via a micropipette. Both serotonin and octopamine enhance the optokinetic effect when applied in low doses. Experiments show that serotonin is most likely acting closer to the sensory input in the optokinetic system.

Animals↗
PubMed1991

Optokinetic response and adaptation of the vestibulo-ocular reflex (VOR) in a patient with chronic cortical blindness.

Optokinetic response and adaptation of the VOR were investigated in a patient with chronic cortical blindness. Our results suggest that: 1) optokinetic response was present in a patient with cortical blindness. This optokinetic response may relate to the extrastriate pathways: 2) the occurrence of VOR adaptation was shown in a patient with cortical blindness, which may indicate preservation of the pathways of the visual-vestibular interaction in the brain stem and cerebellum. The result is in agreement with previous reports in experimental animals; 3) less adaptation of the VOR in this patient than in normal adults may relate to a chronic loss of visual feed back. To the best of our knowledge, this is the first report of adaptation of the VOR in a patient with cortical blindness.

Adaptation, Physiological↗
PubMed1991

Binocular interaction and signal components of optokinetic responses of climbing fiber afferents in the cerebellar flocculus and nodulus of the pigmented rabbit.

Under anesthesia with N2O (70%) and halothane (2-4%), Purkinje cells were extracellularly recorded in the flocculus and nodulus of immobilized pigmented rabbits, and complex spike responses to optokinetic stimulation (OKS) delivered simultaneously to both the ipsi- and contralateral eyes (binocular OKS) were compared with those to OKS monocularly delivered to the ipsi- or contralateral eye (monocular OKS). The complex spike responses to binocular OKS were an approximate summation of monocular responses to ipsi- and contralateral OKS. The complex spike modulation did not correlate with rhythmical slow and quick nystagmic discharges of the oculomotor nerve evoked by horizontal OKS. This suggests that complex spike responses originate largely from 'retinal slip' signals rather than from 'final motor command' signals represented in the discharges of the oculomotor nerve.

Afferent Pathways↗
PubMed1991

Optokinetic response of cells in the nucleus reticularis tegmenti pontis of the pigmented rabbit.

In immobilized pigmented rabbits anesthetized with N2O (70%) and halothane (2-4%), extracellular spikes were recorded from neurons in the nucleus reticularis tegmenti pontks (NRTP) and their responses to optokinetic stimulation (OKS) were examined. OKS was delivered using constant-velocity (0.1-4.0 degrees/s) movements of a random dot pattern (60 degrees x 60 degrees) at 0 degree, 45 degrees, 90 degrees or 135 degrees to the horizon. With OKS delivered to the contralateral eye (n = 43), the preferred directions of NRTP cells were forward (F, n = 10), backward (B, n = 7), downward (D, n = 5), and the remaining cells showed no response (N, n = 21). With OKS delivered to the ipsilateral eye (n = 43), the preferred directions were F (n = 8), B (n = 8), upward (U, n = 2), D (n = 1) and N (n = 24). The majority of cells which responded to OKS (17/22 for contralateral, and 16/19 for ipsilateral OKS) preferred the horizontal orientation. The optimum velocity ranged from 0.2 to 1 degree/s. The results suggest that the NRTP cells mainly transfer horizontal optikinetic signals to the flocculus and control horizontal optokinetic eye movements.

Animals↗
PubMed1991

The effects of simultaneous central and peripheral field motion on the optokinetic response.

The effects of central and peripheral retinal stimulation on the optokinetic response were examined using full-field, central field only, peripheral field only and simultaneous central and peripheral field motion. Stimulation of the central field in isolation produced similar responses to those obtained for full-field motion whereas peripheral field stimulation resulted in greatly reduced responses. Central field dominance was also evident during central and peripheral field motion in opposing directions. However with unidirectional, simultaneous central and peripheral stimulation the optokinetic response was determined not by the central stimulus but by whichever stimulus moved the slower.

Adult↗
PubMedDate not supplied

Vestibular and optokinetic responses of the white cat.

The vestibular and optokinetic responses of a group of white cats were evaluated and compared with the responses from a control group of pigmented animals. The results indicate that in all cases the white cats exhibited varying degrees of vestibular and/or optokinetic dysfunction, which in some animals varied from test session to test session.

Animals↗
PubMed1979

Electro-oculographic and electroencephalographic correlative study of optokinetic responses in brain lesions.

Electro-oculograms of induced optokinetic responses (OKR) and EEG were recorded in 61 patients with either left or right hemisphere lesions. Of the 61 patients 55 showed focal EEG disturbances as follows: occipito-temporal (7 cases), parieto-temporal (10 cases), occipito-parieto-temporal (26 cases), temporal (9 cases) and frontal (3 cases). Symmetric OKR (21 cases) were recorded when no EEG changes were observed or when these were localized to left or right temporal and frontal electrodes and exceptionally when unilateral occipital and parietal regions were also involved. In 40 cases with unilateral hemispheric lesion a contralateral abnormal OKR was observed. Low frequency OKR with or without amplitude changes, especially of fast (saccadic) component, was mainly observed in parietal localization. In severely disturbed OKR, i.e. random jerks, the abnormal brain waves were mainly localized to the occipito-parieto-temporal region. In all cases in which no response was obtained the affected area was the occipito-parieto-temporal. These findings are discussed with reference to the regulating systems of slow (smooth) and fast (saccadic) eye movements triggered by visual stimuli.

Adolescent↗
PubMed1981

Human optokinetic responses under quasi-open and closed loop conditions.

The human optokinetic response to a horizontally moving stripped pattern surrounding the subject was investigated under quasi-open and closed loop conditions. Open loop conditions were produced by the addition of an external signal from measured slow phase eye velocity to stripe velocity. A comparison of open and closed loop responses to step and sinusoidal changes of stripe velocity indicates that the central nervous system controlling slow phase optokinetic following can be described as a simple first order lag (Ka/(s + a)) where K is 4.7 and the time constant, 1/a, is 1.25 s.

Electrooculography↗
PubMed1983

Effects of vestibulocerebellar lesions upon dynamic characteristics and adaptation of vestibulo-ocular and optokinetic responses in pigmented rabbits.

The vestibulo-ocular reflex (VOR) and optokinetic response (OKR) in the horizontal plane were examined in pigmented rabbits, using sinusoidal whole-body rotation and sinusoidal rotation of a striped screen. Sustained rotation of the animal (5 degrees peak-to-peak, 0.1 Hz) for 4 h, under different optokinetic stimulus conditions, induced the following adaptive changes in the VOR: (1) outphase rotation of the screen (5 degrees) increased the VOR gain by 0.3 (on average); (2) with the screen fixed in space, VOR gain increased by 0.2. (3) in-phase rotation of the screen (5 degrees) decreased the VOR gain by 0.16. However, (4) in-phase rotation of the screen at twice (10 degrees) the amplitude of whole-body rotation did not affect the gain. Instead, it induced a significant phase lead (23 degrees) in the VOR, which did not occur in other stimulus conditions. Adaptive increases of the OKR gain occurred under sustained rotation of the screen alone (2.5 degrees, 0.33 Hz). After bilateral destruction of floccular Purkinje cells with kainic acid the VOR gain and phase were affected only very slightly, but adaptive changes in the VOR were abolished. By contrast, the OKR gain was reduced and the OKR phase delayed. OKR adaptation was also affected in such a way that a gain increase initially produced could not be maintained during sustained screen rotation. Ablation of nodulus-uvala caused a gain increase and phase lead in both VOR and OKR, and its only effect on adaptability of the VOR or the OKR was observed for the VOR under stimulus condition (4).

Acclimatization↗
PubMed1990

Horizontal optokinetic responses under stroboscopic illumination in cat, monkey and man.

The horizontal optokinetic reflex (OKN) was studied in cat, monkey and man under conditions of steady or stroboscopic illumination. In all species, there was an abrupt decrease in OKN gain for a given spatial displacement of the stimulus between two consecutive stroboscopic flashes. The upper limit of spatial displacement which preserved optimal OKN gain was independent of stimulus velocity and flash frequency. The value of this limit differed in the three species studied. In the cat, OKN gain was affected when the spatial displacement between two stimuli exceeded 0.55 degrees of visual angle. In monkey and man, these limits were 1.48 degrees and 2.87 degrees, respectively. When human subjects were asked to volontary track the stimulus, the limit value reached 4.3 degrees. This result is discussed in the context of the evolution of the smooth pursuit system and its contribution to optokinetic response.

Adult↗
PubMed1990

Pursuit and optokinetic responses in latent/manifest latent nystagmus.

Abnormalities of foveal smooth pursuit and the monocular optokinetic response (OKR) have often been reported in subjects with latent nystagmus (LN) and manifest latent nystagmus (MLN). This abnormality typically takes the form of a monocular asymmetry with a deficit in the response to nasal-to-temporal (N-T) motion in the visual field. Previous studies have each presented different interpretations of this finding, depending on whether the characteristics of the spontaneous oscillation were considered when analyzing the measured eye movement response: one report has suggested that these asymmetries are in fact the cause of the spontaneous nystagmus. In this study, pursuit and OKRs were examined separately and, when working synergistically and antagonistically, to attempt to overcome this difficulty. Results suggest that pursuit and the OKR could be symmetric in LN and MLN for both binocular and monocular viewing, which leads to the conclusion that the asymmetric patterns of response often reported in LN/MLN result from either shifts in the zone of minimum-intensity oscillation or from non-stimulus-specific increases in the spontaneous nystagmus.

Adolescent↗
PubMed1979

Interaction between the horizontal vestibulo-ocular reflex and optokinetic response in rabbits.

Dynamic characteristics of the horizontal vestibulo-ocular reflex (HVOR), the optokinetic response (OKR), and their interactions were investigated in alert albino rabbits. For stimulation of the horizontal semicircular canals, the whole rabbit was rotated sinusoidally on a motor-driven turntable at peak-to-peak amplitudes of 5 degrees to 30 degrees over a frequency range of 1/30 to 1/2 Hz. Optokinetic stimulation was provided by a narrow vertical slit light source presented in front of the eye to be tested. The evoked horizontal eye movements were observed and measured by means of a closed circuit television system adapted to provide an analog signal proportional to the eye movement. The net HVOR was obtained by rotation of the turntable in darkness and the net OKR by rotation of the light source. Combining rotation of the turntable with a stationary light source immediately increased the gain and reduced the phase shift of the HVOR. The light source moving in phase with the turntable, but at twice the angular amplitude, reduced the gain and advanced the phase of the HVOR. Eye movement curves of the HVOR modified by a fixed or moving slit light could be reconstructed approximately by a linear combination of the net HVOR and OKR.

Animals↗
PubMed1997

The early phase of horizontal optokinetic responses in the pigmented rat and the effects of lesions of the visual cortex.

Horizontal optokinetic responses of pigmented rats were studied both in intact animals and in animals that had received lesions of the visual area of the cerebral cortex. In response to uniform velocity stimulation, there was an initial phase of rapid acceleration, larger than that reported in earlier studies, followed by a period of fairly uniform acceleration until the eye velocity approached that of the stimulus. As reported previously, responses to monocular stimulation were highly asymmetric, with the responses to nasotemporal stimulation being much weaker than those to temporonasal stimulation. Responses to sinusoidal stimulation were also studied. No significant effect of cortical lesions on the responses was seen.

Animals↗
PubMed1995

The optokinetic response differences between congenital profound and nonprofound unilateral visual deprivation.

BACKGROUND: The occurrence of monocular naso-to-temporal optokinetic nystagmus (OKN) asymmetry, as a reflection of the immature oculomotor system in infants, and its persistence with early onset monocular visual deprivation, is well known. This asymmetry has been linked with poor binocular function and attributed to disruption of the development of binocular cortical projections to the pretectum. Optokinetic nystagmus symmetry in patients with congenital uniocular total pattern vision deprivation has not been fully investigated. METHODS: The authors compared the optokinetic responses in six children with "profound" uniocular visual deprivation, who were born with untreated conditions (microphthalmos and persistent hyperplastic primary vitreous), with ten aphakic children treated early for congenital unilateral cataracts (nonprofound unilateral visual deprivation). Eye movements were recorded using dc-electro-oculography, and OKN was elicited using a full-field patterned curtain. Flash and pattern visual-evoked responses were also measured in each subject. RESULTS: Latent nystagmus was present in six children in the nonprofound group, whereas none was detected in the profound group. All children in the nonprofound group showed statistically significant monocular naso-to-temporal asymmetry for either eye. Subjects in the profound group had symmetric OKN. CONCLUSIONS: The authors conclude that unequal input from the two eyes and interocular rivalry lead to OKN asymmetry. Their results suggest that if vision from one eye is so negligible that it does not compete with the neuroanatomic connections of the fellow eye, then the input from this eye remains undisturbed, and OKN remains symmetric.

Adolescent↗
PubMed1983

Vestibuloocular reflex, optokinetic response, and their interactions in the alert cat.

Ocular movements of alert cats were recorded by classical electronystagmography techniques during (a) vestibular stimulation (sinusoidal rotation of the cat in complete darkness), (b) optokinetic stimulation (sinusoidal rotation of the visual surroundings around the stationary cat), (c) additive visual-vestibular stimulation (sinusoidal rotation of the cat inside the stationary lighted surroundings), and (d) conflicting visual-vestibular stimulation (sinusoidal rotation of the cat together with the visual surroundings in phase and at the same speed). The stimulus amplitudes and frequencies ranged from 3 to 20 degrees and from 0.025 to 1 Hz, respectively. When tested in darkness, the vestibuloocular reflex (VOR) gain was about 0.9 at 1 Hz. At lower frequencies, this gain was a bit lower and a phase lead was observed. The VOR system was nearly linear. The optokinetic response (OKR) gain was about 1 at lower frequencies but strongly decreased at higher frequencies. A phase lag paralleled that decrease in gain. Furthermore, the smaller the amplitude of the visual stimulus, the better the effectiveness of OKR stabilization. When working in the light, the VOR was in phase with the stimulus and its gain was nearly 1, whatever the frequency and the amplitude. The VOR inhibition was more effective at lower frequencies. In these conditions the system was markedly amplitude-dependent for both gain and phase.

Animals↗