• Korean Journal of Biological Psychiatry
• /
• v.2 no.2
• /
• pp.275-280
• /
• 1995

Smooth pursuit eye movement, one of the reliable biological markers of schizophrenia, is not always abnormal in schizophrenic patients. Therefore the authors studied it in schizophrenic patients and normal controls and compared the results according to the presence or abscence of family history of psychosis and types (type I and type II). The results are as follows: 1) In the 18 normal control group (8 mole, 10 female), there was no sex difference in the responses of smooth pursuit eye movement. 2) In th 44 schizophrenic group (28 male, 16 female), there also was no sex difference in the responses of smooth pursuit eye movement. 3) In comparison of 44 schizophrenic group to 18 normal control group, there was significantly increased abnormal response in smooth pursuit eye movement in schizophrenic group (P < 0.005). 4) In schizophrenic group, there was no difference in the responses of smooth pursuit eye movement between type I and type II schizophrenia. 5) The presence or abscence of family history of psychosis made no difference in the responses of smooth pursuit eye movement in schizophrenic group. 6) Subdivision of type I or type II in each case of presence or abscence of family history made no difference in the responses of smooth pursuit eye movement in schizophrenic group.

• Annals of Clinical Neurophysiology
• /
• v.1 no.2
• /
• pp.173-181
• /
• 1999

Eye movements serve vision by placing the image of an object on the fovea of each retina, and by preventing slippage of images on the retina. The brain employs two modes of ocular motor control, fast eye movements (saccades) and smooth eye movements. Saccades bring the fovea to a target, and smooth eye movements prevent retinal image slip. Smooth eye movements comprise smooth pursuit, the optokinetic reflex, the vestibulo-ocular reflex (VOR), vergence, and fixation. Saccades achieve rapid refixation of targets that fall on the extrafoveal retina by moving the eyes at peak velocities that can exceed $700^{\circ}/s$. Various brain lesions can affect saccadic latency, velocity, or accuracy. Smooth pursuit maintains fixation of a slowly moving target. The pursuit system responds to slippage of an image near the fovea in order to accelerate the eyes to a velocity that matches that of the target. When smooth eye movements velocity fails to match target velocity, catch-up saccades are used to compensate for limited smooth pursuit velocities. The VOR subserves vision by generating conjugate eye movements that are equal and opposite to head movements. If the VOR gain (the ratio of eye velocity to head velocity) is too high or too low, the target image is off the fovea, and head motion causes oscillopsia, an illusory to-and-fro movement of the environment.

• Journal of the Korean Society of Physical Medicine
• /
• v.17 no.4
• /
• pp.113-121
• /
• 2022

PURPOSE: This study is examined the effects of vestibular stimulation through eye movement on balance and muscle activity. METHODS: In 42 healthy adults, no eye exercise was applied to both feet and one foot. The speed of smooth pursuit eye movement (.2 Hz, .3 Hz, and .5 Hz) and saccadic eye movement (.5 Hz and 1.1 Hz) were randomized. The measurements were taken three times for 30 seconds while standing on two feet and measured three times for 10 seconds while standing on one foot. The muscle activity measurement equipment was used to measure the electromyogram signals of the tibialis anterior, peroneus longus, gastrocnemius medialis, vastus medialis, vastus lateralis, biceps femoris, abdominal internal oblique, and erector spinae muscle. RESULTS: As a result of this study, when applying smooth pursuit eye movement on one leg, the pressure center movement increased, the muscle activity of the lower extremity increased, in the saccadic eye movement, and the center of pressure decreased. CONCLUSION: Accordingly, the smooth pursuit of eye movement, the intervention of this study, affects balance. Through this, the balance can be improved by applying eye movement to the target who needs to improve the balance ability.

• Journal of the Korea Convergence Society
• /
• v.9 no.5
• /
• pp.121-127
• /
• 2018

The objective of the present study was to investigate the effect of eye movement on cognitive ability using Mini-Mental State Examination for Dementia Screening (MMSE-DS) and the amplitude and latency of P300 from event-related potentials after 55 elderly participants were randomly stratified into the saccadic eye movement (SEM) group and the smooth pursuit eye movement (SPEM) group, and performed eye movement for 4 weeks. As a result, P300 amplitude significantly increased and P300 latency significantly shortened in the SEM and SPEM groups. MMSE-DS showed a significant increase in both groups; upon comparing the groups, the SEM group showed a significant difference in orientation and the SPEM group in attention. In conclusion, it is thought that SEM and SPEM can improve and maintain the cognitive ability of the elderly and may be used as therapeutic tools for dementia prevention and mild dementia.

• Annals of Clinical Neurophysiology
• /
• v.25 no.2
• /
• pp.55-65
• /
• 2023

The ultimate role of ocular movements is to keep the image of an object within the fovea and thereby prevent image slippage on the retina. Accurate evaluations of eye movements provide very useful information for understanding the functions of the oculomotor system and determining abnormalities therein. Such evaluations also play an important role in enabling accurate diagnoses by identifying the location of lesions and discriminating from other diseases. There are various types of ocular movements, and this article focuses on saccades, fast eye movements, smooth pursuit, and slow eye movements, which are the most important types of eye movements used in evaluations performed in clinical practice.

• Korean Journal of Biological Psychiatry
• /
• v.6 no.1
• /
• pp.119-124
• /
• 1999

This study was done to examine whether cigarette smoking improved smooth pursuit eye movement(SPEM) abnormalities in chronic schizophrenic inpatients. Fifteen schizophrenic and twelve alcoholic subjects abstained from their usual cigarette smoking for a minimum of nine hours and their baseline performances during the constant velocity smooth pursuit tasks were assessed. Then, the subjects smoked as much as they desired in a 10 minutes period and were retested immediately after smoking and 15 minutes after smoking. Electrooculographic recordings during the eye movements were converted and saved as digitized files. Power spectral density curves and natural logarithm value of signal/noise(Ln S/N) ratios were computed from them. In the schizophrenic patients, Ln S/N ratios increased significantly immediately after smoking compared to baseline. But, Ln S/N ratios showed no statistically significant changes after 15 minutes compared to baseline. In alcoholic subjects, Ln S/N ratios showed no statistically significant changes immediately after smoking and after 15 minutes compared to baseline. In conclusion, SPEM was improved in schizophrenic patients immediately after smoking and we hypothesized that nicotinic receptor dysfunction maybe a candidate mechanism for smooth pursuit eye movement abnormalities in schizophrenia.

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

• Therapeutic Science for Rehabilitation
• /
• v.6 no.1
• /
• pp.71-83
• /
• 2017

Objective : This study aim is to identify whether smooth pursuit eye movement(SPEM) using portable device can alleviate chronic hemispatial neglect. Methods : We applied smooth pursuit eye movement to one chronic hemispatial neglect patient. Experimental duration was total 4weeks - 1week baseline, 2weeks SPEM intervention, 1week 2nd. baseline. The intervention was 10 SPEM sessions (30min each, 1session daily, from Monday to Friday) over a period of 2weeks. The neglect test carried out 5 times a week. The SPEM was provided on the screen when patient sat in front of the screen(8.4 inch tablet pc, distance 40cm). The SPEM 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 SPEM for 2weeks, the degree of neglect tended to decrease compared to baseline A. The degree of the LBT tended to increase the at the baseline A'. In contrast, the SCT showed that tendency which the degree of the neglect maintained at the baseline A'. Conclusion : We identified that SPEM using portable device is effective intervention method for chronic hemispatial neglect.

• Journal of the Ergonomics Society of Korea
• /
• v.16 no.1
• /
• pp.1-13
• /
• 1997

In this research, and investigation of the eye movement was performend when the objects perceived by the eye are three-dimensional objects, two dimensional images, and trhee dimensional images. This investigation was done by observing the EQG(Electro- oculogram) waves which were obtained from experiments. The observed waves were categorized into several groups. Differences among the waves were analyzed for each object and image perceived by the eye. In order to obtain waves for analysis, two kinds of experiments were performen. In each experiment, the saccadic eye movement and the smooth pursuit eye movement were considered as an independent variables. Waves obtained from the experiments were categorized into 4 types (Wave-1, Wave-2, Wave-3, Wave-4) depending on their characteristics. Unlike the other images, three dimensional image was revealed as a key factor for the active movement of the eye. Futhermore, a unique eye movement was observed in the case of three dimensional images where the focus of the eye was achieved through three steps.

• Annals of Clinical Neurophysiology
• /
• v.13 no.1
• /
• pp.13-20
• /
• 2011

Neuro-ophthalmological findings are common and occasionally prominent features in movement disorders. Accordingly, careful evaluation of the ocular motor functions may provide valuable information in early detection of the diseases and monitoring of the progression. Furthermore, accurate assessment of the abnormal ocular motor findings aids in understanding the pathophysiology and mechanisms of the movement disorders, and in their differential diagnosis. Ocular motility examination should include bedside evaluation and laboratory recording of the fixational abnormalities, saccades, smooth pursuit, the vestibulo-ocular reflex, optokinetic nystagmus, and vergence eye movements. In this review, we will discuss various ocular motor findings in ataxia and parkinsonian syndromes, and hyperkinetic movement disorders.