• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.455-458
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• 1997

We are exposed to the various external stimuli input from the environment, which cause emotional changes based on the characteristics of the stimuli. Unfortunately, there are no quantitative results on relationship between human sensibility and the characteristics of physiological signals. The objective of this study was to quantify EEG signals evoked by visual stimulation based on the assumption that the analysis of the variability on the characteristics of the EEG waveform may provide the significant information regarding changes in psychological states of the subject. Seven university students were participated in this study. The experiment was devised with eleven experimental conditions, which are control and ten different types of visual stimulation based on IAPS (International Affective Picture Systems). Wavelet transformation was employed to analyze the EEG signals. Most positive and negative emotional response were compared in pairs. The results showed that the reconstructed signals at the decomposition level revealed the different energy value on the EEG signals. Also, general patterns of EEG signals in rest state compare with positive and negative stimulus were found. This study could be extended to establish an algorithm which distinguishes psychophysiological states of the subjects exposed to the visual stimulation.

• PNF and Movement
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• v.22 no.1
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• pp.91-99
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• 2024

Purpose: Backward walking has shown positive effects on gait recovery in rehabilitation patients. It is increasingly used as an aerobic training method in rehabilitation populations, inducing more sensory and motor stimulation than forward walking. Therefore, the purpose of this study is to investigate the effects of visual stimulation during backward walking. Methods: Twenty-seven healthy adults with a visual acuity of 0.8 or higher participated in the study. To compare the effects of visual stimulation during various walking conditions among healthy individuals, the participants randomly selected cards numbered one to six and walked a distance of 10 meters. Walking ability was measured using Optogait. Results: Statistically significant differences were observed in speed, stride, and percentages of single support and contact phase during backward walking. Within eyes-closed conditions during backward walking, significant differences were found in percentages of single support, terminal stance, and contact phase. Moreover, the percentage of terminal swing significantly differed during backward walking with head turn conditions. Conclusion: Gait parameters such as speed, stride, and percentages of single support and contact phase were higher during backward walking than forward walking. These results indicate that backward walking involves multiple sensory systems and varying conditions.

• Physical Therapy Rehabilitation Science
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• v.5 no.3
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• pp.125-131
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• 2016

Objective: The purpose of this study was to investigate the effects of providing visual feedback and auditory stimulation using a robotic device on balance and gait abilities in stroke patients. Design: Randomized controlled pilot trial. Methods: Fifteen subjects were randomly divided into three groups where five subjects were in the visual feedback robotic device assist gait training (VRGT) group, five subjects in the auditory stimulation robotic device assist gait training (ARGT) group, and five subjects in the control group. Subjects received visual feedback and auditory stimulation while undergoing robotic gait training for 45 minutes, three times a week for 2 weeks, and all subjects had undergone general physical therapy for 30 minutes, five times a week for 2 weeks. All subjects were assessed with the Berg balance scale (BBS), timed up and go (TUG) test, and 10-meter walking test (10MWT) pre- and post-intervention. Results: All subjects showed that BBS, TUG test, and 10MWT scores significantly improved post-intervention (p<0.05), and the control group also had significantly improved post-treatment (p<0.05). The VRGT and the ARGT showed significant improvements in BBS, TUG, and 10MWT scores compared with the control group (p<0.05). The VRGT group showed a significant improvement in BBS, TUG, and 10MWT scores compared with the control group (p<0.05). In addition, it has been confirmed that VRGT had significantly improved in BBS, TUG test, and 10MWT scores compared with the auditory stimulation and control group (p<0.05). Conclusions: The results of this study showed improved balance and gait abilities after VRGT and ARGT groups compared with general physical therapy and was found to be effective in enhancing the functional activity of persons affected with stroke.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.6
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• pp.524-530
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• 2002

A control of the body posture and movement is maintained by the vestibular system, vision, and proprioceptors. Afferent signals from those receptors are transmitted to the vestibular nuclear complex, and the efferent signals from the vestibular nuclear complex control the eye movement and skeletal muscle contract. The postural disturbance caused by loss of the vestibular function results in nausea, vomiting, vertigo and loss of craving for life. The purpose of this study is to develop a off-vertical rotatory system for evaluating the function of semicircular canals and otolith organs, selectively, and visual stimulation system for- stimulation with horizontal, vortical and 3D patterns. The Off-vortical axis rotator is composed of a comportable chair, a DC servo-motor with reducer and a tilting table controlled by PMSM. And a double feedback loop system containing a velocity feedback loop and a position feedback loop is applied to the servo controlled rotatory chair system. Horizontal, vertical, and 3D patterns of the visual stimulation for applying head mounted display are developed. And wireless portable systems for optokinetic stimulation and recording system of the eye movement is also constructed. The gain, phase, and symmetry is obtained from analysis of the eye movement induced by vestibular and visual stimulation. Detailed data were described.

• The Korean Journal of Physiology and Pharmacology
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• v.27 no.6
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• pp.541-553
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• 2023

Retinal prostheses have shown some clinical success in restoring vision in patients with retinitis pigmentosa. However, the post-implantation visual acuity does not exceed that of legal blindness. The reason for the poor visual acuity might be that (1) degenerate retinal ganglion cells (RGCs) are less responsive to electrical stimulation than normal RGCs, and (2) electrically-evoked RGC spikes show a more widespread not focal response. The single-biphasic pulse electrical stimulation, commonly used in artificial vision, has limitations in addressing these issues. In this study, we propose the benefit of multiple consecutive-biphasic pulse stimulation. We used C57BL/6J mice and C3H/HeJ (rd1) mice for the normal retina and retinal degeneration model. An 8 × 8 multi-electrode array was used to record electrically-evoked RGC spikes. We compared RGC responses when increasing the amplitude of a single biphasic pulse versus increasing the number of consecutive biphasic pulses at the same stimulus charge. Increasing the amplitude of a single biphasic pulse induced more RGC spike firing while the spatial resolution of RGC populations decreased. For multiple consecutive-biphasic pulse stimulation, RGC firing increased as the number of pulses increased, and the spatial resolution of RGC populations was well preserved even up to 5 pulses. Multiple consecutive-biphasic pulse stimulation using two or three pulses in degenerate retinas induced as much RGC spike firing as in normal retinas. These findings suggest that the newly proposed multiple consecutive-biphasic pulse stimulation can improve the visual acuity in prosthesis-implanted patients.

• Proceedings of the KOSOMBE Conference
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• v.1993 no.05
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• pp.21-24
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• 1993

The experimental results of visual stimulation with the tailored RF pulse are reported. Tailored RF pulse is used for the susceptibility effect imaging. Around 25% signal change of visual cortex area is detected during photic stimulation. Interestingly, with the tailored RF pulse, the signal intensity of visual cortex is deceased during photic stimulation. It is, however, increased with normal $T_2$ weighted imaging. The comparison between normal $T_2$ weighted imaging and the tailored RF pulse imaging are performed with 4T NMR system and the results with human volunteer are also presented.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.539-542
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• 2005

In this study, we investigated the influence of vibrational stimulation on postural control. To study the effect, the sway of the center of pressure was observed fur two different visual conditions and for three different patterns of vibrational stimulation on plantar area. The two visual conditions were normal condition with visual feedback and blind condition with both eyes closed. The three vibrational stimulations were white noise, constant vibration, and vibration with amplitude modulations (sine curve modulation). The experimental results showed that the sway of the center of pressure distinctively reduced with white noise vibrational stimulation. This result showed that it's possible to use vibrational stimulation for improving the ability of postural control.

• Korean Journal of Radiology
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• v.1 no.1
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• pp.19-24
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• 2000

Objective: In order to investigate the functional brain anatomy associated with verbal and visual working memory, functional magnetic resonance imaging was performed. Materials and Methods: In ten normal right handed subjects, functional MR images were obtained using a 1.5-T MR scanner and the EPI BOLD technique. An item recognition task was used for stimulation, and during the activation period of the verbal working memory task, consonant letters were used. During the activation period of the visual working memory task, symbols or diagrams were employed instead of letters. For the post-processing of images, the SPM program was used, with the threshold of significance set at p < .001. We assessed activated brain areas during the two stimulation tasks and compared the activated regions between the two tasks. Results: The prefrontal cortex and secondary visual cortex were activated bilaterally by both verbal and visual working memory tasks, and the patterns of activated signals were similar in both tasks. The superior parietal cortex was also activated by both tasks, with lateralization to the left in the verbal task, and bilaterally without lateralization in the visual task. The inferior frontal cortex, inferior parietal cortex and temporal gyrus were activated exclusively by the verbal working memory task, predominantly in the left hemisphere. Conclusion: The prefrontal cortex is activated by two stimulation tasks, and this is related to the function of the central executive. The language areas activated by the verbal working memory task may be a function of the phonological loop. Bilateral prefrontal and superior parietal cortices activated by the visual working memory task may be related to the visual maintenance of objects, representing visual working memory.

• The Journal of the Korea Contents Association
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• v.20 no.10
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• pp.199-215
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• 2020

The purpose of this study is to understand dogs for their happy lives. Experiment and survey were conducted to find out the effects of sensory stimulation on dogs emotions. Sensory were divided into visual, auditory, olfactory, tactile, complex and emotions were measured by the rate of deep sleep, feed intake, and heart rate. Research has shown that complex stimulation (walking) is the most positive stimulation for dog's emotions, but visual stimulation and auditory stimulation do not act as stimuli that positively change usual state of dog's emotions. Olfactory stimuli is the second best stimulation. Since olfactory stimulation is effective in maintaining a calm state without large deviation in the dog's state, it can be used as a method for relieving the dog's stress in exceptional situations when complex stimulation is not possible. On the other hand, tactile stimulation, bath, is a negative sensory stimulus that causes hypersomnia and binge eating for most dogs.

• Journal of Korean Physical Therapy Science
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• v.26 no.1
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• pp.35-44
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• 2019

Purpose: The purpose of this study is to investigate the effect of visual and auditory stimulation randomly applied to healthy adults on walking. Design: Randomized Controlled Trial. Methods: Twenty-six healthy students in S college were randomly divided into visual feedback group (n=13) and auditory feedback group (n=13). The visual feedback group walked using four conditions. 1) In the red screen was shown, clap twice to the right, 2) In yellow screen, clap twice to the left, 3) In green screen, clap twice over head. 4) Do not clap in purple screen. The auditory feedback group walked using four conditions. 1)in red, clap twice to the right, 2) In yellow, clap twice left, 3) In green, clap twice over your head. 4) Do not clap in purple. All subjects measured gait variables before and after the test using G-walker. Result: The visual feedback group showed a significant decrease (p<.05) in the number of steps per minute, walking speed, and step length compared with that of normal walking. The auditory feedback group showed a significant decrease (p<.05) in the number of steps per minute, walking speed, and step length than that of normal walking. Conclusion: The results of this study suggest that visual and auditory stimulation applied to healthy adults may have significant effects on walking.