Neuronal activity in the dorsolateral pontine nucleus of the alert monkey modulated by visual stimuli and eye movements

1988 ◽  
Vol 70 (3) ◽  
Author(s):  
P. Thier ◽  
W. Koehler ◽  
U.W. Buettner
Keyword(s):  
Eye Movements ◽  
Neuronal Activity ◽  
Visual Stimuli ◽  
Alert Monkey ◽  
Pontine Nucleus ◽  
Dorsolateral Pontine Nucleus

Smooth-Pursuit Eye-Movement Deficits With Chemical Lesions in Macaque Nucleus Reticularis Tegmenti Pontis

1999 ◽  
Vol 82 (3) ◽  
pp. 1178-1186 ◽  
Author(s):  
David A. Suzuki ◽  
Tetsuto Yamada ◽  
Rebecca Hoedema ◽  
Robert D. Yee
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Ibotenic Acid ◽  
Frontal Eye Field ◽  
Smooth Pursuit Eye Movements ◽  
Pontine Nucleus ◽  
Nucleus Reticularis Tegmenti Pontis ◽  
Pursuit Eye Movements ◽  
Nucleus Reticularis ◽  
Dorsolateral Pontine Nucleus

Anatomic and neuronal recordings suggest that the nucleus reticularis tegmenti pontis (NRTP) of macaques may be a major pontine component of a cortico-ponto-cerebellar pathway that subserves the control of smooth-pursuit eye movements. The existence of such a pathway was implicated by the lack of permanent pursuit impairment after bilateral lesions in the dorsolateral pontine nucleus. To provide more direct evidence that NRTP is involved with regulating smooth-pursuit eye movements, chemical lesions were made in macaque NRTP by injecting either lidocaine or ibotenic acid. Injection sites first were identified by the recording of smooth-pursuit-related modulations in neuronal activity. The resulting lesions caused significant deficits in both the maintenance and the initiation of smooth-pursuit eye movements. After lesion formation, the gain of constant-velocity, maintained smooth-pursuit eye movements decreased, on the average, by 44%. Recovery of the ability to maintain smooth-pursuit eye movements occurred over ∼3 days when maintained pursuit gains attained normal values. The step-ramp, “Rashbass” task was used to investigate the effects of the lesions on the initiation of smooth-pursuit eye movements. Eye accelerations averaged over the initial 80 ms of pursuit initiation were determined and found to be decremented, on the average, by 48% after the administration of ibotenic acid. Impairments in the initiation and maintenance of smooth-pursuit eye movements were directional in nature. Upward pursuit seemed to be the most vulnerable and was impaired in all cases independent of lesioning agent and type of pursuit investigated. Downward smooth pursuit seemed more resistant to the effects of chemical lesions in NRTP. Impairments in horizontal tracking were observed with examples of deficits in ipsilaterally and contralaterally directed pursuit. The results provide behavioral support for the physiologically and anatomic-based conclusion that NRTP is a component of a cortico-ponto-cerebellar circuit that presumably involves the pursuit area of the frontal eye field (FEF) and projects to ocular motor-related areas of the cerebellum. This FEF-NRTP-cerebellum path would parallel a middle and medial superior temporal cerebral cortical area-dorsolateral pontine nucleus-cerebellum pathway also known to be involved with regulating smooth-pursuit eye movements.

Neural activity in dorsolateral pontine nucleus of alert monkey during ocular following responses

1992 ◽  
Vol 67 (3) ◽  
pp. 680-703 ◽  
Author(s):  
K. Kawano ◽  
M. Shidara ◽  
S. Yamane
Keyword(s):  
Eye Movements ◽  
Firing Rate ◽  
Visual Stimulus ◽  
Temporal Frequency ◽  
Large Field ◽  
Pontine Nucleus ◽  
Stimulus Speed ◽  
Ocular Following ◽  
Dorsolateral Pontine Nucleus ◽  
Random Dot Pattern

1. Movements of the visual scene evoke short-latency ocular following responses. To study the neural mediation of the ocular following responses, we investigated neurons in the dorsolateral pontine nucleus (DLPN) of behaving monkeys. The neurons discharged during brief, sudden movements of a large-field visual stimulus, eliciting ocular following. Most of them (100/112) responded to movements of a large-field visual stimulus with directional selectivity. 2. Response amplitude was measured in two components of the neural response: an initial transient component and a late sustained component. Most direction-selective DLPN neurons showed their strongest responses at high stimulus speeds (80-160 degrees/s), whether their response components were initial (63/87, 72%) or sustained (63/87, 72%). The average firing rates of 87 DLPN neurons increased as a linear function of the logarithm of stimulus speed up to 40 degrees/s for both initial and sustained responses. 3. Not only the magnitude but also the latency of the neural and ocular responses were dependent on stimulus speed. The latencies of both neural and ocular responses were inversely related to the stimulus speed. As a result, the time difference between the response latencies for neural and ocular responses did not vary much with changes of stimulus speed. 4. Response latency was measured when a large-field random dot pattern was moved in the preferred direction and at the preferred speed of each neuron. Seventy-three percent (56/77) of the neurons were activated less than 50 ms after the onset of the stimulus motion. In most cases (67/77, 87%), their increase of firing rate started before the eye movements, and 34% of them (26/77) started greater than 10 ms before the eye movements. 5. Blurring of the random dot pattern by interposing a sheet of ground glass increased the latency of both neural responses and eye movements. On the other hand, the blurred images did not change the timing of the effect of blanking the visual scene on the responses of the neurons or eye movements. 6. When a check pattern was used instead of random dots, both neural and ocular responses began to decrease rapidly when the temporal frequency of the visual stimulus exceeded 20 Hz. When the temporal frequency of the visual stimulus approached 40 Hz, the neurons showed a distinctive burst-and-pause firing pattern. The eye movements recorded at the same time showed signs of oscillation, and their temporal patterns were closely correlated to those of the firing rate.(ABSTRACT TRUNCATED AT 400 WORDS)

Smooth-pursuit eye movement deficits with chemical lesions in the dorsolateral pontine nucleus of the monkey

1988 ◽  
Vol 59 (3) ◽  
pp. 952-977 ◽  
Author(s):  
J. G. May ◽  
E. L. Keller ◽  
D. A. Suzuki
Keyword(s):  
Steady State ◽  
Eye Movements ◽  
Smooth Pursuit ◽  
Visual Motion ◽  
Ibotenic Acid ◽  
Smooth Pursuit Eye Movements ◽  
Optokinetic Response ◽  
Pontine Nucleus ◽  
Pursuit Eye Movements ◽  
Dorsolateral Pontine Nucleus

1. Anatomical and single-unit recording studies suggest that the dorsolateral pontine nucleus (DLPN) in monkey is a major link in the projection of descending visual motion information to the cerebellum. Such studies coupled with cortical and cerebellar lesion results suggest a major role for this basilar pontine region in the mediation of smooth-pursuit eye movements. 2. To provide more direct evidence that this pontine region is involved in the control of smooth-pursuit eye movements, focal chemical lesions were made in DLPN in the vicinity of previously recorded visual motion and pursuit-related neurons. Eye movement responses were subsequently recorded in these lesioned animals under several behavioral paradigms. 3. A major deficit in smooth-pursuit performance was produced after unilateral DLPN lesions generated either reversibly with lidocaine or more permanently with ibotenic acid. Pursuit impairments were observed during steady-state tracking of sinusoidal target motion as well as during the initiation of pursuit tracking to sudden ramp target motion. Through the use of the latter technique, initial eye acceleration was reduced to less than one-half of normal for animals with large lesions of the dorsolateral and lateral pontine nuclei. 4. The pursuit deficit in all animals was directional in nature and was not dependent on the visual hemifield in which the motion stimulus occurred. The largest effect for horizontal tracking occurred in all animals for pursuit directed ipsilateral to the lesion. Animals also showed major deficits in one or both directions of vertical pursuit, although the primary direction of the vertical impairment was variable from animal to animal. 5. Chemical lesions in the DLPN also produced comparable deficits in the initiation of optokinetic-induced smooth eye movements in the ipsilateral direction. In contrast to this effect on the initial optokinetic response, in the one lesioned animal studied during prolonged constant velocity optokinetic drum rotation, smooth eye speed increased slowly over a 10- to 15-s period to reach a level that closely matched drum speed. These results suggest that pathways outside the DLPN can generate the steady-state optokinetic response. 6. Saccades to stationary targets were normal after DLPN lesions, but corrective saccades made to targets moving in the direction ipsilateral to the lesion were much more hypometric than similar prelesion control saccades. 7. The pursuit deficits produced by lidocaine injections recovered within 30 min. The ibotenic acid deficits were maximal approximately 1 day after the injection and recovered rapidly thereafter over a time period of 3-7 days.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Directed Gaze Trajectories for Biometric Presentation Attack Detection

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1394
Author(s):  
Asad Ali ◽  
Sanaul Hoque ◽  
Farzin Deravi
Keyword(s):  
Eye Movements ◽  
Visual Stimuli ◽  
Attack Detection ◽  
Movement Data ◽  
Biometric Systems ◽  
Planar Geometries ◽  
Presentation Attack Detection

Presentation attack artefacts can be used to subvert the operation of biometric systems by being presented to the sensors of such systems. In this work, we propose the use of visual stimuli with randomised trajectories to stimulate eye movements for the detection of such spoofing attacks. The presentation of a moving visual challenge is used to ensure that some pupillary motion is stimulated and then captured with a camera. Various types of challenge trajectories are explored on different planar geometries representing prospective devices where the challenge could be presented to users. To evaluate the system, photo, 2D mask and 3D mask attack artefacts were used and pupillary movement data were captured from 80 volunteers performing genuine and spoofing attempts. The results support the potential of the proposed features for the detection of biometric presentation attacks.

scholarly journals Saliency-Based Gaze Visualization for Eye Movement Analysis

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5178
Author(s):  
Sangbong Yoo ◽  
Seongmin Jeong ◽  
Seokyeon Kim ◽  
Yun Jang
Keyword(s):  
Eye Movements ◽  
Visual Attention ◽  
Eye Movement ◽  
Visual Stimuli ◽  
Saliency Map ◽  
Gaze Behavior ◽  
The Gaze ◽  
Movement Data ◽  
Visual Clues ◽  
Human Visual Attention

Gaze movement and visual stimuli have been utilized to analyze human visual attention intuitively. Gaze behavior studies mainly show statistical analyses of eye movements and human visual attention. During these analyses, eye movement data and the saliency map are presented to the analysts as separate views or merged views. However, the analysts become frustrated when they need to memorize all of the separate views or when the eye movements obscure the saliency map in the merged views. Therefore, it is not easy to analyze how visual stimuli affect gaze movements since existing techniques focus excessively on the eye movement data. In this paper, we propose a novel visualization technique for analyzing gaze behavior using saliency features as visual clues to express the visual attention of an observer. The visual clues that represent visual attention are analyzed to reveal which saliency features are prominent for the visual stimulus analysis. We visualize the gaze data with the saliency features to interpret the visual attention. We analyze the gaze behavior with the proposed visualization to evaluate that our approach to embedding saliency features within the visualization supports us to understand the visual attention of an observer.

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