• Proceedings of the Korean Society for Cognitive Science Conference
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• 2005.05a
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• pp.228-232
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• 2005

최근의 연구에서 Li. Brenner, Cornelissen과 Kim (2002)은 추적 눈 운동 동안의 2차원 모양지각이 망막에 형성된 이미지 내용을 그대로 반영한다는 것을 보여 주었는데, 이러한 연구는 2차원 모양판단에 있어서 눈 운동 정보가 전혀 고려되지 않았음을 시사한다. 이와 같은 실험실 연구와 달리, 실제 생활에서 2차원 모양지각의 왜곡은 대부분의 경우에 발생하지 않는데, 가능한 한 가지 이유는 실험실 연구에서 사용된 자극의 경우에 참조대상이 존재하지 않는데 비하여, 실제 생활에서는 다양한 참조대상이 목표대상의 주변에 존재하기 때문이다. 목표대상과 참조대상의 상대적인 위치관계는 추적 눈 운동 동안에 망막에서도 그대로 유지되는데 시각체계가 이러한 안정적인 관계를 목표 대상의 모양을 지각할 때에 이용할 가능성이 있다. 본 연구에서는 다양한 참조대상을 이용하여 이러한 가능성을 검증하였다. 특히, 피험자의 눈 운동을 눈 운동 측정기를 이용하여 측정하였으며, 적절한 눈 운동을 수행한 시행에서의 데이터만 분석에 사용하였다.

• Korean Journal of Cognitive Science
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• v.14 no.3
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• pp.51-59
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• 2003

Various perceptual distortions in spatial vision occur during eye movements. Most of the studies on perceptual distortion have focused on the conjunctive eye movements. Recently, Li, Kham, Kim & Yoon (2002) reported that subjects experienced perceptual distortion of 3D slant of an object defined by the spatiotemproal pattern of occlusion. The present research examined whether the subjects experienced the same perceptual distortion in the target object whose luminance is different from that of background. It also examined the effect of the reference on the perceptual distortion of 3D slant of an object.

• Korean Journal of Cognitive Science
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• v.16 no.3
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• pp.175-188
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• 2005

Recently, Li, Brenner, Cornelissen and Kim (2002) reported that 2D shape perception during pursuit eye movement just reflected the retinal image, and this result implies that the visual system ignored the extra-retinal information. In reality, however, we usually do not experience the perceptual distottion of 2D shape during pursuit eye movement. One Possibility is that the visual system night exploit the fact that the relative location between objects on retinal image is constantly maintained even during pursuit eye movement. The present research examined this possibility. Interestingly, perceptual distortion of 2D shape was observed even in the presence of reference, however, the amount of distortion decreased compared to when the reference does not exist. The distance between the reference and the target affected the perceptual distortion. These results imply that reference information is used in 2D shape perception during pursuit eye movement but it cannot completely explain the stable and accurate representation of 2D shape perception during pursuit eye movement.

• Korean Journal of Cognitive Science
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• v.13 no.2
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• pp.37-45
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• 2002

Despite dynamical retinal image changes caused by pursuit eye movements, we usually perceive the stable spatial properties of the environment suite successfully Helmholtz and his followers have suggested that the visual system coordinates the retinal and extraretinal eye position information to represent the spatial properties of the environment. However. there have been a significant amount of researches showing that this kind of mechanism may not operate perfectly, and the pursuit eye movement employed in those researches were limited to conjugate eye movements. When an observer tracks an object moving away from the observer with his/her eyes. the two eyes rotate in opposite direction. and this kind of disjunctive eye movement may produce undesirable binocular disparities for the objects in the background. The present study examined whether the visual system compensated for the undesirable binocular disparities caused by disjunctive eye movements with extraretinal eye position information. Although the target object was presented frontoparellely to the subjects. the subjects reported that the object was slanted toward (or alway from) them in consistent with the undesirable binocular disparities produced by the disjunctive eye movements. These results imply that the visual system may not perfectly compensate for the undesirable binocular disparities with extraretinal eye position information.

• Korean Journal of Cognitive Science
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• v.15 no.3
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• pp.15-24
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• 2004

The perceived position of a flashing target object is generally biased towards the direction of eye movement when there is no reference around the target. Current research examined the localization accuracy of a flashing target relative to a static reference. The perceived location of the target relative to the reference was distorted and the pattern of perceptual distortion systematically depended on the position of the reference relative to the target. This kind of result was consistently observed regardless of the distance between the reference and the target and direction of pursuit eye movement. We have discussed how these results could he explained by the theories previously suggested to explain the localization of objects.

• Therapeutic Science for Rehabilitation
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• v.5 no.2
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• pp.81-92
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• 2016

Objective: This study aim is to identify whether 30minutes optokinetic stimulation(OKS) with smooth pursuit eye movement can alleviate chronic hemispatial neglect. Methods: We applied optokinetic stimulation with smooth pursuit eye movement to 2 chronic hemispatial neglect patients. experimental duration was total 4weeks - 1week baseline, 2weeks OKS intervention, 1week 2nd. baseline. The intervention was 10 OKS sessions (30min each, 1session daily, from Monday to Friday) over a period of 2weeks. The neglect test carried out 3 times a week every other day. The OKS was provided on the screen when patient sat in front of the screen(13.5 inch). The OKS video that the 24 yellow squares moving coherently from the right to the left side. Patients were instructed to perform smooth pursuit eye movement without head and neck movement. Results: As a result of the OKS for 2weeks, the degree of neglect trends to decrease on both 2 cases compared to baseline A. The degree of the neglect of subject 1 tended to increase the at the baseline A. In contrast, the subject 2 showed that tendency that the degree of the neglect declined additionally at the baseline A. Conclusions: We identified that 30 minutes optokinetic stimulation with sooth pursuit eye movement is effective intervention method for chronic hemispatial neglect.

• Korean Journal of Cognitive Science
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• v.34 no.2
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• pp.67-84
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• 2023

In this study, Korean older adults (70-75 yrs) were divided into two groups according to the degree of reading exposure, and real-time data were collected through a reading eye movement tracking experiment. Then, overall reading patterns and word frequency ef ects were compared with two groups of older adults and younger adults (20-28 yrs). Furthermore, through the results of the eye movement tracking experiment of older adults with rich reading exposure and older adults with poor reading exposure, we tried to find out whether reading performance af ects not only changes in age but also reading exposure. As a result of the experiment, the older adults with poor reading exposure group generally had a longer fixation time and a shorter saccade than the younger adults group, and the older adults with rich reading exposure group showed the same reading patterns as the younger adults group. The word frequency ef ect was confirmed in all groups, and the fixation time was short in the order of older adults with rich reading exposure group and older adults with poor reading exposure group. In addition, an interaction ef ect was shown in the two elderly groups according to reading exposure, but no interaction could be confirmed in the dif erence between the younger adults group and the older adults with rich reading exposure group. This suggests the possibility that reading performance is not af ected by age itself, but by the reading experience of the elderly.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2471-2473
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• 2003

인간의 안구는 색과 모양을 식별하는 데에 관여하는 원추 세포와 물체의 명암을 구분하는 간상 세포로 구성되어지는 시세포를 가진다. 망막 위에 분포되어 있는 시세포들은 시축을 중심으로 각기 다른 밀도로 분포 되어 있다. 특히 광축과 만나는 중심 지역은 Fovea라고 하는 직경 1mm 정도의 작은 우물을 이루고 있는데 원추 세포들이 고해상도로 분포되어 있고 시신경과 일대일로 연결되어 있어 시각 처리의 중심이 된다. 특히, 글자나 물체를 인식하기 위해 인간은 대상물을 응시하여 대상물의 영상이 Fovca영역에 맺히도록 추적 운동을 계속한다. 본 논문에서는 인간의 눈과 유사한 망막 모델의 하나인 Log-polar Image를 이용한 물체 인식을 위해 물체를 Log-polar Image Plane의 중심에 위치시키기 위한 모멘텀(Momentum)기반 정합 알고리즘(Alignment Algorithm)을 제시한다. 이는 눈동자 운동이 가능한 능동형 시각 장치의 Tracking 및 Pursuit 동작 중에 밭생하는 추적 오차를 보상함으로써 운동 중에도 효과적인 물체 인식이 가능하게 한다. 또한, 물체를 Log-polar Image Plane의 중심에 위치시킴으로써 물체의 위치 이동, 회전이동 그리고 크기 변화에 무관하게 물체를 인식한 수 있음을 제시한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.5
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• pp.1171-1176
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• 2014

The eye-tracking [ET] is used on the human computer interaction [HCI] analysing the movement status as well as finding the gaze direction of the eye by tracking pupil's movement on a human face. Nowadays, the ET is widely used not only in market analysis by taking advantage of pupil tracking, but also in grasping intention, and there have been lots of researches on the ET. Although the vision based ET is known as convenient in application point of view, however, not robust in changing environment such as illumination, geometrical rotation, occlusion and scale changes. This paper proposes two steps in the ET, at first, face and eye regions are discriminated by Haar classifier on the face, and then the pupils from the discriminated eye regions are tracked by CAMShift as well as Template matching. We proved the usefulness of the proposed algorithm by lots of real experiments in changing environment such as illumination as well as rotation and scale changes.

• The Journal of Korean Academy of Sensory Integration
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• v.21 no.3
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• pp.39-53
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• 2023

Objective : The purpose was the effect of sensory integration therapy combined with an eye tracker on the sensory processing and visual perception of children with developmental disabilities. Methods : It was a single-subject study with a multiple baseline design between subjects, and the intervention applied sensory integration therapy combined with an eye tracker. Visual-motor speed and saccadic eye movements were assessed at each session of baseline and intervention periods. As pre- and post-evaluation, sensory profile, Korean-Developmental Test of Visual Perception and Trail Making Test were conducted. The results of each session evaluation and pre- and post-evaluation researched the effectiveness of the intervention through visual analysis and trend line analysis. Results : As a result of the evaluation for each session, the slope of the trend line for all children in visual-motor speed and saccadic eye movement increased sharply during the intervention compared to the baseline. As a result of the pre- and post-evaluation, the sensory processing of movement, body position, and visual changed from more than that of peers to a level similar to that of peers. In visual perception, all children's ability of Visual Closure increased. As a result of Trail Making Test conducted to confirm the improvement of children's visual tracking and visual-motor abilities, all children showed a decrease in performance time after the test compared to before. Conclusion : It was confirmed that sensory integration therapy combined with an eye tracker for developmental disabilities has effect on sensory processing and visual perception. It is expected to play an important role clinically as it can stimulate children's interest and motivation in line with recent technological improvements and the spread of smart devices.