• Title/Summary/Keyword: Saccadic movement

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Saccadic Movement as a Performance Measure of Vigilance Task (경계작업 척도로서의 안구운동 특성)

  • Lee, Myeon-U;Lee, Gwan-Haeng;Jo, Yeong-Jin
    • Journal of Korean Institute of Industrial Engineers
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    • v.8 no.1
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    • pp.13-21
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    • 1982
  • Experiments on the eye movement behavior were performed using Vidicon Eye Camera. Factorial design ( $3{\times}3$) was used to evaluate the validity of the eye movement as a performance measure in vigilance task. Eye movement data were recorded in video tapes, then the data were converted to digital signals, which were reduced to quantitative fixation and saccadic movement data by a microcomputer. To compare with existing vigilance performance measures, response time and the number of false alarms were also recorded. The results showed that the saccadic movement is a good measure of the performance in vigilance task : 1. Both the response time and the saccadic movement increased significantly during the initial two time blocks. 2. High correlations were shown between the response time and the saccadic movement. 3. The locational uncertainty affects the saccadic movement, the number of fixations, the response time but doesn't affect the duration of eye fixations.

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Characteristics of Corrective Saccadic Eye Movement with E.O.G. (E.O.G.를 이용한 Corrective Saccadic 안구운동 특성)

  • 김윤수;박상희
    • Journal of Biomedical Engineering Research
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    • v.2 no.1
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    • pp.21-30
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    • 1981
  • In this study, measuring eye movements with E.O.G. to targets beyond 20$^{\circ}$ from fixation point, results are as follows. (1) When the eyes turn toward targets of more than 20$^{\circ}$ eccentricity, the first saccadic eye movement falls short of the target. The presence of image of the target off the fovea(visual error signal) subsequent to such an undershoot elicits, after short interval, corrective saccadic eye movements(usually one) which place the image of the target on the fovea. (2) There are different programming modes at retina for eye movement to targets within and beyond 20$^{\circ}$ from the fixation point. (3) Saccadic system, preparing the direction and amplitude of eye movement completes the corrective saccadic eye movements. (4) Distribution of latency and intersaccadic interval(I.S.I.)are frequently multi modal, with a seperation between modes of 25[msec]. (5) There are two types of saccadic eye movements for the double-step targets. This fact suggests that the visual information is sampled stochastically. (6) The new model of saccadic system including the dissociation of visual functions dependent on retinal eccentricity is required.

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Velocity Characteristics of Horizontal Saccadic Eye Movement (수평 Saccadic 안구운동의 속도 특성에 관한 연구)

  • 박상희;이상효
    • Journal of Biomedical Engineering Research
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    • v.3 no.1
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    • pp.17-22
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    • 1982
  • In this paper, peak velocity characteristics of saccadic eye movements were measured and analyzed as a velocity characteristics of horizontal saccadic eye movement system. Measurements were made with an infrared reflection method, and horizontal saccadic eye movements of 5 normal subject were recorded for the periodic and random pulse targets of 5$^{\circ}$, 10$^{\circ}$, 20$^{\circ}$ , and 30$^{\circ}$ amplitudes.

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Implementation of saccadic eye movement system with saliency map model (Saliency map 모델을 갖는 도약 안구 시각 시스템의 구현)

  • Cho, Jun-Ki;Lee, Min-Ho;Shin, Jang-Kyoo;Koh, Kwang-Sik
    • Journal of Sensor Science and Technology
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    • v.10 no.1
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    • pp.52-61
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    • 2001
  • We propose a new saccadic eye movement system with visual selective attention. Saliency map models generate the scan pathways in a natural scene, of which the output makes an attended location. Saccadic eye movement model is used for producing the target trajectories to move the attended locations very rapidly. To categorize human saccadic eye movement, saccadic eye movement model was divided into three parts, each of which was then individually modeled using different neural networks to reflect a principal functionality of brain structures related with the saccadic eye movement in our brain. Based on the proposed saliency map models and the saccadic eye movement model, an active vision system using a CCD type camera and BLDC motor was developed and demonstrated with experimental results.

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The Velocity Characteristics of the Vertical Saccadic Eye Movement System (수직 Saccadic 안구운동계의 속도 특성)

  • 이용천;박상희
    • Journal of Biomedical Engineering Research
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    • v.4 no.1
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    • pp.15-20
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    • 1983
  • In this paper, the velocity characteristics of the vertical saccadic eye movement system with subject-experiment are investigated utilizing the infra-red methed. Especially, target-generation system which produces pseudo-random signals using EPROM 2716 and differentiator whose time constant is 12 msec are developed in hardware.

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A Study on the Duration of the Horizontal Saccadic Eye Movement (수평 saccadic 안구운동의 지속시간에 관한 연구)

  • 김광수;김용우
    • Journal of Biomedical Engineering Research
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    • v.6 no.2
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    • pp.23-28
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    • 1985
  • In this paper, the the duration of horizontall saccadic eye movement is studied alls measurement system is designed using microprocessor to obtain the quantitized data The duration is measured using the beginning and ending points of the saccadic velocity threshold. The results obtained are as follows. 1. The average duration of the saccade for angle displacement of 0$^{\circ}$ to 20$^{\circ}$ lies between 25 and 60 msec, and represents the increasing curve except 9$^{\circ}$ and 12$^{\circ}$ 2. The average duration lfor angle displacement of 5$^{\circ}$,10$^{\circ}$,15$^{\circ}$, and 20$^{\circ}$ is 40, 48, 57.5, and 62 msec, respectively. 3. Nasal movement has a little longer duration than temporeal movement. 4. The duration is not concerned with subject's will.

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Eye Movement-based Visual Discomfort Analysis from Watching Stereoscopic 3D Contents Regarding Brightness and Viewing Distance (눈 움직임을 이용한 밝기와 시청거리에 따른 3D 콘텐츠 피로도 분석)

  • Kim, Yong-Woo;Kang, Hang-Bong
    • Journal of Korea Multimedia Society
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    • v.19 no.9
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    • pp.1723-1737
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    • 2016
  • When watching 3D contents, people often experience various visual discomforts like tiredness, dryness, headaches, and dizziness. Previous researches on visual discomfort analyzed and concluded vergence-accommodation conflict, viewing distance, and brightness changes to be the causes of visual discomfort. Yet it is necessary to systematically analyze the visual discomfort due to the changes in object, background brightness and viewing distance. In this paper, we produce four videos that have four different background brightness and two different viewing distances to solve analyze the visual discomfort from watching 3D contents. We measure and analyze eye-blink and saccadic movement, saccadic latency, Nearest Point of Convergence (NPC), and participant survey for amore accurate result compared to previous researches. Our results show that the eye-blink rate and saccadic latency increase when the background is bright and viewing distance is close while the saccadic movement decreases in the same environment. However, NPC only changes when the background brightness changes. We confirm that the bright background and near viewing distance create greater visual discomfort and decrease depth perception abilities.

A new approach for the saccadic eye movement system simulation (Saccade 안구운동계의 시뮬레이션)

  • 박상희;남문현
    • 전기의세계
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    • v.26 no.1
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    • pp.87-90
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    • 1977
  • Various simulation techniques were developed in the modeling of biological system during the last decades. Mostly analog and hybrid simulation techniques have been used. The authors chose the Digital Analog Simulation (DAS) technique by using the MIMIC language to simulate the saccadic eye movement system performances on the digital computer. There have been various models presented by many investigators after Young & Stark's sampled-data model. The eye movement model chosen by the authors is Robinson's model III which shows the parallel information processing characteristics clearly to the double-step input stimuli. In the process of simulation, the parameter and constants used were based on the neurophysiological data of the human and animals. The analog model blocks were converted to the corresponding MIMIC block diagrams and programmed into the MIMIC statements. The program was run on the CDC Cyber 72-14 computer. The essential input stimulus was double-step of 5 and 10 degrees, and target durations chosen were 50,100 and 150 msec. The results obtained by the DAS technqiue were in good agreement with analog simulation carried out by other investigators as well as with the experimental human saccadic eye movement responses to double-step target movements.

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Cerebellar Control of Saccades (소뇌의 단속안구운동 조절)

  • Choi, Jae-Hwan;Choi, Kwang-Dong
    • Annals of Clinical Neurophysiology
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    • v.15 no.2
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    • pp.37-41
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    • 2013
  • Saccades are rapid eye movements that shift the line of sight between successive points of fixation. The cerebellum calibrates saccadic amplitude (dorsal vermis and fastigial nucleus) and the saccadic pulse-step match (flocculus) for optimal visuo-ocular motor behavior. Based on electrophysiology and the pharmacological inactivation studies, early activity in one fastigial nucleus could be important for accelerating the eyes at the beginning of a saccade, and the later activity in the other fastigial nucleus could be critical for stopping the eye on target, which is controlled by inhibitory projection from the dorsal vermis. The cerebellum could monitor a corollary discharge of the saccadic command and terminate the eye movement when it is calculated to be on target. The fastigial nucleus and dorsal vermis also participate in the adaptive control of saccadic accuracy.

Eye Movement Program Consisting of Saccadic Eye Movement and Pursuit Eye Movement Improved Visual Memory in Institutionalized Elderly Person: Randomized controlled pilot study

  • Park, Yongnam;Bae, Youngsook
    • Journal of International Academy of Physical Therapy Research
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    • v.10 no.2
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    • pp.1768-1773
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    • 2019
  • Background: Aging reduces cognitive abilities, including visual memory (VM) and visual discrimination (VD). Since common cortical networks subserve eye movement and attention, voluntary eye movement may improve visual attention. Visual selective attention was major role for memory, and visual memory and visual attention are intimately related. Objective: To identify the improvement in VD and VM, after implementing the eye movement program consisting of saccadic eye movement (SEM) and pursuit eye movement (PEM) in the institutionalized healthy elderly. Design: Randomized controlled trial. Methods: The study involved a sample of 36 participants, and the mean age was 79.03 years (range 76~84 years). They were randomly allocated to the experimental group (n=16) and control group (n=20). Participants in the experimental group performed SEM 5 times per week for 4 weeks: twice daily at the same time in the morning and afternoon. The program was carried out for 3 minutes, and it consisted of SEM and PEM. The target's moving frequency was set at 0.5 Hz. VM and VD at the baseline and post-intervention were measured using Motor-Free Visual Perception test-4 (MFVPT-4). Results: VM significantly improved in the experimental group (p < .01), and significant differences were observed compared to the control group (p < .01). There was no significant change in VD. Conclusion: The eye movement program consisting of SEM and PEM increased VM more than VD. Therefore, eye movement program was feasible interventions for improving VM in institutionalized elderly persons.