• Title/Summary/Keyword: eye-fixation

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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.

A Case of Congenital Progressive Bilateral Convergent & Divergent Strabismus with Unilateral Exophthalmus in Holstein Cattle (선천성 진행성 양측성 내외측성 사시 및 편측성 안구돌출증 홀스타인 1예)

  • Jung, Young-Hun;Hur, Tai-Young;Choe, Chang-Yong;Kang, Seog-Jin;Lee, Hyun-June;Ki, Kwang-Seok;Park, Yung-Sang;Suh, Guk-Hyun;Kim, Jong-Taek
    • Journal of Veterinary Clinics
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    • v.29 no.4
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    • pp.344-347
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    • 2012
  • Bilateral convergent strabismus with exophthalmus(BCSE) is an eye disorder affecting many cattle breeds worldwide. BCSE is the most common in cattle at various types of strabismus. Divergent strabismus is of relatively low incidence than convergent strabismus. This report is the to shown a case of convergent and divergent strabismus with unilateral in the exophthalmus in a heifer Holstein cow. A female Holstein calf born with congenital progressive divergent strabismus in right eye and convergent strabismus in left eye was tested. Ocular and blood examination, and activity were checked from the first week, 8 month, and 16 month after birth. The ocular examination includes general inspection, fixation reflex and menace response. The general inspection is checking the degree of deviation of both eyes from the normal visual axis, which was determined by the amount of sclera permanently visible in the temporal corner of the eye. The stage is divided into 4 stages depending on the degree of deviation. The right eye shown in stage 4 continues after birth and the left eye shown stage 2, stage 3 and stage 4 at 1 week, 8 month and 16 month after birth, respectively. In fixation reflex and Menace response, both eye balls showed a normal response at 1 week, 8 month and 16 month after birth. Blood count and serum chemistry test were performed, but a specific factor was not detected outside the reference range.

Analysis of Processes in Reading about 'Science Stories' in 6th Grade Science Textbook Using Eye-tracking (안구운동 추적 기법을 활용한 6학년 과학 교과서의 과학 이야기 읽기 과정 분석)

  • Park, Hyojeong;Shin, Donghoon
    • Journal of The Korean Association For Science Education
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    • v.35 no.3
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    • pp.383-393
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    • 2015
  • This study analyzed the 6th grade elementary science textbook 'Science stories' reading process of students by utilizing eye movement tracking techniques. Participants read 3 articles in the new experimental science textbooks and solved 9 problems about each article. By understanding and academic achievement results, participants were divided into high-groups, middle-groups, and low-groups. The results of eye movement characteristics of the high-groups and low-groups had the following differences. Number of fixations and number of regressions were higher in high-groups. Average fixation duration and average regressive fixation duration were longer in low-groups. Fixation time for the key sentence of the article was longer in high-groups. Analysis of a scan path and post-interview, high-groups had frequent regression between sentences and they knew where the core of the article is and paid much attention there. In contrast low-groups are sequentially read most articles and some of them had a leap of abnormal range. Problem-solving approach is also different between groups. In conclusion reading style is associated with the science stories comprehension and students who had more regressions, much core search process, effective attention distribution, high concentration showed better understanding results. Also words or sentences used in textbooks are associated with science stories comprehension.

The Development of Intervention Program for Enhancing Elementary Science-Poor Students' Basic Science Process Skills - Focus on Eye Movement Analysis - (초등과학부진학생의 기초과학탐구능력 향상을 위한 중재프로그램 개발 -안구운동을 중심으로-)

  • Shin, Won-Sub;Shin, Dong-Hoon
    • Journal of The Korean Association For Science Education
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    • v.34 no.8
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    • pp.795-806
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    • 2014
  • The purpose of this study is to develop an intervention program for improvement of elementary science-poor students' Basic Science Process Skill (BSPS) and to validate the intervention program's effectiveness using eye-tracker. The participants of this study were 35 elementary science-poor students. This study's method was the analysis of real-time eye movements during basic science process skill problem solving. SMI's 120 Hz iView XTM RED was used to collect EMD (eye movement data). Experiment 3.4 and BeGaze 3.4 programs were used to design experiment and to analyze EMD. The results of this study are as follows. First, we developed an intervention program including BSPS instructional strategy, behavior of teachers & student according instructional strategy stage, teachinglearning plan and learning note. Second, science poor students' BSPS ability has improved statistically significantly through the application of intervention program and BSPS problem-solving time decreased statistically significantly. Third, AFT (average fixation time) of BSPS Question and keyword area decreased statistically significantly. Fourth, APD (average pupil diameter) of BSPS problem-solving process expanded statistically significantly. Fifth, AST (average saccade time) of BSPS problem-solving process increased statistically significantly. Sixth, AFET (average fixation entry time) of BSPS problem-clue area was accelerated statistically significantly, AFT of BSPS problem-clue area reduced statistically significantly.

The perceptual span of Junior-high school students in Korean reading (우리글 읽기에서 중학생들의 지각폭 연구)

  • Choi, Soyoung;Koh, Sungryong
    • Korean Journal of Cognitive Science
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    • v.25 no.3
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    • pp.189-210
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    • 2014
  • The present study investigated the perceptual span(or the span of effective vision) of junior-high school students during reading Korean, using the material and the moving-window display change technique used in Choi & Koh(2009). The 8 different window sizes were used in the experiment. They were 3, 5, 7, 9, 11, 13, 15 characters in size and the whole line. Reading rate, number of fixation, saccadic distance, fixation duration were compared between each window-size condition and the whole line condition. Considering the pattern of eye-movement measures above, the size of the perceptual span of junior-high school students in Korean reading may be estimated to be 9 characters, that is 4 characters to the right and 1 characters to the left of the fixation.

One Boundary Diffusion Model Analysis on Distributions of Eye Fixation Durations in Reading; Eye Movement Tracking Study (우리글 읽기에서 나타난 성인과 청소년의 고정시간 분포분석과 단일경계 확산모형 제안)

  • Choo, Hyeree;Koh, Sungryong
    • Korean Journal of Cognitive Science
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    • v.32 no.1
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    • pp.1-53
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    • 2021
  • The aim of this study was to analyze word frequency effects on eye fixation duration in Korean reading with a one-boundary diffusion model and to show how these phenomena differ between adults (20-28yrs) and adolescents (13-14yrs). We predicted that the drift rate parameter in the boundary diffusion model would reflect the information processing of the fovea during silent reading. Through an eye movement tracking experiment while controlling word properties such as the word frequency and the age of acquisition, Experiment 1 and Experiment 2 show that the information processing pertaining to words to be placed in the fovea is connected to the drift rate of the one-boundary diffusion model parameters. In Experiment 1,in the adult group, the mean difference in the fixation time in the response proportion between the presence of high-frequency condition and low-frequency condition in the adult group was higher in quantile 0.9 than it was in the 0.1 quantile, but in the adolescent group, the mean difference in the fixation time in the response proportion between the two conditions was not significantly in the 0.9 quartile.In Experiment 2, the mean difference in the fixation time in the response proportion between early-acquired condition and late-acquired condition in both groups was also higher in the quantile 0.9 than in the 0.1 quantile. The distribution of the two conditions in the both groups was positively skewed, and the difference showed the same pattern found in the results of Ratcliff(Ratcliff & McKoon, 2008). Based on the experimental results, we propose one-boundary diffusion model as a tool to explain word property effects and individual differences in reading. In particular, we suggest that the drift rate parameter in the boundary diffusion model reflects the information processing of the fovea during reading. In addition, the results show that one-boundary diffusion model can be used to predict the aforementioned phenomena in reading.

A Study of Evaluating Eye Movement Based on Ocular Motor Score for Children with Spastic Cerebral Palsy

  • Jeong, Seo-Young;Oh, Tae-Young
    • The Journal of Korean Physical Therapy
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    • v.32 no.6
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    • pp.341-347
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    • 2020
  • Purpose: The purpose of this study is to introduce a tool for evaluating eye movement and analyze the reliability of measurement based on 10 cases of evaluating the oculomotor function of children with spastic cerebral palsy Methods: The participants were selected by 6 medical and welfare institutions in Busan as GMFCS grade 1-3 among spastic diplegia and hemiplegia. Seven examiners evaluated 3 children for the evaluation of inter-rater agreement of Ocular Motor Score (OMS) and evaluated the condition of the ocular motor of 10 children using OMS, a re-examination was performed at six weeks after the initial examination. SPSS ver.25.0 was used to calculate the interclass correlation coefficient and Wilcoxon's signed-rank test, Mann Whitney-U test. Results: The inter-rater agreement of OMS was 0.89. Second mean values were decreased compared first examination in motility/ductions/version, saccades and smooth pursuit, but there was no significant difference. Children under 6 years old had a high mean value of saccades in first examination and the motility/ductions/version, fixation, saccades in second examination, but there was no significant difference. Spastic diplegia children's mean values were higher in head posture, fixation in 8 gaze directions than hemiplegia children in both first and second examination, but there were no significant differences. Conclusion: Ocular motor function in 10 children of spastic children who participated in the study and could see that the scores was differed depending on age, type, grade of cerebral palsy. OMS may be available for this purpose.

Comparative Study on Eye-Tracking Evaluation and Landscape Adjectives Evaluation - Focusing on the Nightscape of a University Campus - (아이트래킹 평가 방법과 경관 형용사 평가 비교 연구 - 대학 캠퍼스 야간경관을 대상으로 -)

  • Kang, Young-Eun;Kim, Song-Yi;Baek, Jae-Bong
    • Journal of the Korean Institute of Landscape Architecture
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    • v.46 no.1
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    • pp.38-48
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    • 2018
  • The purpose of this study is to improve the understanding of visual perception and to extend the landscape evaluation area by comparing eye-tracking evaluation and landscape adjective evaluation methods towards various type of nightscapes. As a result of the study, it showed that 'blink count', 'fixation duration average', and 'saccade duration average' of eye tracking measurements have a significant correlation with 'beautiful', 'interesting', 'accessible', 'satisfying', and 'safe' regarding landscape adjectives. In addition, there was a tendency toward areas of interests (AOIs) depending on 12 different nightscapes, which showed that the gaze was fixated by focusing on certain landscape elements such as 'door' and 'signs'. These results suggest that the eye-tracking method is an effective tool to specify the evaluation of 'landscape elements' rather than the 'whole landscape' and can be used as a basis to support landscape preference theories, which has been presented as conceptual only. In this way, the results of this study demonstrated the possibility of various applications of eye tracking as an objective landscape evaluation technique, and it is possible to suggest specific implications to landscape planning through the accumulation of continuous research results.

Development of the Heuristic Attention Model Based on Analysis of Eye Movement of Elementary School Students on Discrimination task (변별과제에서 초등학생의 안구운동 분석을 통한 발견적 주의 모델 개발)

  • Shin, Won-Sub;Shin, Dong-Hoon
    • Journal of The Korean Association For Science Education
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    • v.33 no.7
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    • pp.1471-1485
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    • 2013
  • The purpose of this study was to develop a HAM (Heuristic Attention Model) by analyzing the difference between eye movements according to the science achievement of elementary school students on discrimination task. Science achievement was graded by the results of the Korea national achievement test conducted in 2012 for a random sampling of classes. As an assessment tool to check discrimination task, two discrimination measure problems from TSPS (Test of Science Process Skill, developed in 1994) which were suitable for an eye tracking system were adopted. The subjects of this study were 20 students from the sixth grade who agreed to participate in the research. SMI was used to collect EMD (eye movement data). Experiment 3.2 and BeGaze 3.2 programs were used to plan experiments and analyze EMD. As a result, eye movements of participants in discrimination tasks varied greatly in counts and duration of fixation, first fixation duration, and dwell time, according to students' science achievement and difficulty of the problems. By the analysis of EMD, strategies of the students' problem-solving could be found. During problem solving, subjects' eye movements were affected by visual attention; bottom-up attention, top-down attention and convert attention, and aflunter attention. In conclusion, HAM was developed, and it is believed to help in the development of a science learning program for underachievers.

A Study of the Variation Factors of Intraocular Pressure (안압 변동 요인에 관한 연구)

  • Kim, Sang-Moon
    • Journal of Korean Ophthalmic Optics Society
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    • v.13 no.1
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    • pp.131-135
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    • 2008
  • Purpose: To measure and quantify the factors of intraocular pressure (IOP) variation for normal Korean youth. Methods: The IOP of normal youth 805 persons (male: 367, female: 438) were measured as a function of time and quantity for fixation, reclining posture, hard blinking, drinking water, drinking hard liquor, tobacco and coffee by using non-contact tonometer (AT555, Reichert Co.). In the case of fixation, reclining posture and hard blinking, the intraocular pressure of right and left eye were measured for 6 males and 6 females every 10 minutes during 30 minute. In the case of water, liquor, tobacco and coffee, the measurement for 4 or 5 groups (6 persons/ group) having similar IOP were done for the IOP variation of right eye. Results: The mean IOP was 15.2 mmHg for males and 15.8 mmHg for females (slightly higher than male's), respectively and the 99% of those were in the range of the normal IOP. The measured IOP was increased by fixation, reclining posture and hard blinking with males and females. The gradient of increasing slope was 0.15/0.13/0.07/0.08, 0.09/0.08/0.08/0.08 and 0.19/0.08/0.26/0.31, respectively. The IOP variation was elevated by drinking water (especially in the case of 1000 ml) and lowered in proportion to the amount of drinking by hard liquor. Cigarette smoking was associated with rise in intra ocular pressure, but was not shown a definite relation. And coffee had virtually no effect. Conclusions: Fixation, reclining posture, hard blinking and Tobacco caused a transient increase in IOP, but alcohol elicited a slight reduction in IOP overall.

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