• Sleep Medicine and Psychophysiology
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• v.1 no.1
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• pp.20-28
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• 1994

The field of applied biofeedback as one of psychophysiological self regulation techniques began in the united states in 1950s. Biofeedback may be described as information about the effects of a response that is given to the person making that response in order to improve ways of controlling that response. This article reviewed various definitions of biofeedback, learning models, mediating processes, instrumentations to be considered during biofeedback practice, treatment procedures and clinical applications.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2002.05a
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• pp.107-113
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• 2002

We examined the psychophysiological effects of navigation in a virtual reality (VR). Subjects were exposed to the VR, and required to detect specific objects. Ten electrophysiological signals were recorded before, during, and after navigation in the VR. Six questionnaires on the VR experience were acquired from 45 healthy subjects. There were significant changes between the VR period and the pre-VR control period in several psychophysiological measurements. During the VR period, eye blink, skin conductance level, and alpha frequency of EEG were decreased but gamma wave were increased. Physiological changes associated with cybersickness included increased heart rate, eye blink, skin conductance response, and gamma wave and decreased photoplethysmogram and skin temperature. These results suggest an attentional change during VR navigation and activation of the autonomic nervous system for cybersickness. These findings would enhance our understanding for the psychophysiological changes during VR navigation and cybersickness.

• Sleep Medicine and Psychophysiology
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• v.9 no.1
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• pp.61-67
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• 2002

Objectives: This study is aimed at measuring psychophysiological responses using a biofeedback system in healthy people to obtain basic normative data for biofeedback research and treatment. Methods: Ninety-six healthy volunteers (55 males and 41 females : average age $30.4{\pm}8.0$) without any history of major medical or psychiatric illnesses participated in this study. Psychophysiological responses were assessed using the ProComp+ and BioGraph program (ver. 2.1) with regard to forearm and frontal electromyography (EMG), electrodermal response (EDR), and skin temperature. They were measured in 3 phases (baseline, stress, and recovery phases), respectively. Beck depression inventory and Spielberger state and trait anxiety inventory were used to measure mood states. We compared psychophysiological responses according to age and gender differences, respectively and examined the relationship between mood states and psychophysiological measures. Results: People in their twenties showed higher EDR levels in the 3 phases than those of other age groups. Female subjects showed higher frontal EMG levels in the 3 phases compared with male subjects. There was no significant correlation between biofeedback measures and mood states in these subjects. Conclusion: We present normative data of psychophysiological responses measured by a biofeedback system in healthy people. These results suggest that gender and age should be considered as important variables in assessing psychophysiological responses using a biofeedback system.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.25 no.2
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• pp.11-18
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• 2002

Psychological and physiological effects of the simulator sickness could be important bias factors for the sensibility evaluation. The purpose of the present study was to clear the differences of psychophysiological responses due to individual sensitivity of simulator sickness. The present experiment tried to investigate the simulator sickness objectively by observing the change of the simulator sickness for the different level of sickness groups (sick and non_sick group). The subjective evaluations using Simulator Sickness Questionnaire (SSQ) and physiological responses were measured every five minutes when they were driving as 60km/h in the driving graphic simulator. Response level of the subjective evaluation for all subjects on the simulator sickness was linearly increased with time for every item, and the response level of sick group was bigger than that of non_sick group. When the analysis on central nervous system was done separately on the sick and the non_sick group, there was significant difference in the parameter $\theta$/total at Fz and Cz. Although the analysis on autonomic nervous system for all subjects showed the increased activation of sympathetic nervous system, there was no significant difference between the sick and non_sick group. In summary, it is necessary to select the subjects who feel less simulator sickness in order to be accurate sensibility evaluation. The parameters to distinguish between the sick and non_sick group were the change on $\theta$/total and subjective evaluation using SSQ.

• Anxiety and mood
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• v.6 no.2
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• pp.102-108
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• 2010

Objective : Although studies have explored responses to fear had been assessed using various psychophysiological methods, results have been inconsistent. The present study examined psychophysiological responses in healthy subjects after viewing fear stimuli in a video clip for set up future fear related psychophysiological studies. Methods : We monitored three psychophysiological variables (electroencephalography, skin temperature, and heart rate variability) in adults who watched either a control stimulus movie clip or a fear-inducing movie clip. Results : In 16 healthy adults, theta activity decreased significantly after the fear stimulus as compared to the normal stimulus. However the participants showed no differences in heart rate variability or skin temperature between the fear and normal control stimulus situations. Conclusion : In the limbic area, theta activity corresponds with information processing, integration into previous memories and long-term potentiation. In this study, we suggest decreased theta activity represents amygdalo-hippocampal activity, associated with fear, short-term memory, and memory extinction in the healthy adults. Further studies are needed to evaluate the interaction of fear, memory, and the pathophysiology of anxiety disorder in patient with anxiety disorders.

• Journal of the Ergonomics Society of Korea
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• v.30 no.1
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• pp.203-211
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• 2011

Objective: The aim of this study is to introduce a methodology to assess driver's emotion stability by using bio-signals. Background: Psychophysiological analysis of driver's behavior has been conducted to improve the driving safety and comfort. However, the variability of bio-signal and individual difference made it difficult to assess the psychophysiological status of drivers that can be expressed as emotional stability of drivers. Method: Two experimental studies were reviewed and summarized. New techniques assessing emotional stability of drivers were explained. Statistical concept and multidimensional space were used to identify the emotionally stable conditions. Conclusion: Psychophysiological approach can provide information of driver's emotional status. The experimental methodology and algorithm used in this study showed the possibility of parameterization of psychophysiological response. Application: Currently measured statistical and geometrical data can be further applied to develop an interactive device monitoring and reacting driver's emotion when driver experiences emotionally unstable or uncomfortable situation.

• Sleep Medicine and Psychophysiology
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• v.8 no.1
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• pp.59-66
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• 2001

Objectives: This study examined the effect of mood and personality characteristics on psychophysiological responses measured by a biofeedback system in a normal population. Methods: Fifty healthy volunteers without any history of medical or psychiatric illnesses participated in this study. We measured the Spielberger trait anxiety inventory, Beck depression inventory, and Eysenck personality questionnaires in these subjects. Using the J & J biofeedback system, we also measured skin temperature, electrodermal response, forearm and frontal electromyography (EMG)s in 3 experimental conditions of baseline, stress, and recovery phases. Results: Trait anxiety did not show any significant correlation with psychophysiological responses except stress response in forearm EMG levels(r=0.282, p<0.05). Depressed mood was negatively correlated with forearm EMG levels in baseline (r=-0.299, p<0.05) and recovery phases(r=-0.314, p<0.05). Subjects with relatively high levels of depressed mood showed different stress and recovery responses in frontal EMG levels compared with those with relatively low levels of depressed mood (F=4.26, p<0.05). Extroverted subjects showed higher levels of forearm EMG than introverted ones in stress phase. Conclusion: Mood and personality characteristics in healthy subjects are closely related with psychophysiological responses measured by a biofeedback system. We suggest that mood and personality characteristics should be considered as important variables in analyzing abnormal psychophysiological responses in some psychiatric patients.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2000.06a
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• pp.260-263
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• 2000

In order to catch the relationship between psychophysiological symptoms and human work performance, the ERP technique was adopted as a measure, and two different tasks - a counting task and an Odd-Ball task were conducted. According to the results, the P300 amplitude during the counting task was not so high as that during the Odd Ball task, and correct response corresponded with stable ERP with high P300 amplitude whereas wrong response with unstable, fluctuating ERP with low P300 amplitude, Therefore it was concluded that it would be possible to grasp the symptoms of human errors with the help of psycho-physiological technique.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2002.05a
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• pp.186-189
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• 2002

The footwear such as socks and shoes is the clothing which are necessary to our life. In this study, clothing comfort of the footwear was carried out by physiological responses and subjective evaluation. As a result, the effect to walking comfort by the height of a heel in female shoes became clear. Then suitability evaluation system of shoes was proposed from the measuring results. On the other hands, the clothing comfort of the hosiery was evaluated from ECG analysis. By this analysis, it became clear that the factor which influences the clothing comfort of the hosiery was the clothes pressure in the hosiery. In the future, plane shape of the foot and solid shape must be considered in order to design the hosiery.

• The Journal of Korean Physical Therapy
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• v.32 no.2
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• pp.132-136
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• 2020

Purpose: The talk test (TT) is an alternative, self-reported method for prescribing and guiding exercise training in both healthy adults and patients with cardiovascular and pulmonary diseases. This study examined whether the TT is a valid tool for evaluating the exercise intensity during two different types of aerobic activity on a treadmill or stationary bicycle in a healthy population. Methods: A total of ten subjects (six males and four females) who had no medical history related to musculoskeletal, cardiovascular, and pulmonary disorders were enrolled in this study. They were evaluated using the TT, which consisted of three-level of difficulties demanding cardiac loads while performing aerobic activities on a treadmill and bicycle ergometer across two consecutive days in a counterbalanced manner. During the activities, the psychophysiological response markers were collected in terms of the heart rate, oxygen saturation, rating of perceived exertion, and metabolic equivalents. Results: Statistical analyses revealed a significant difference in the between-subject variance regarding the TT level effect (p<0.05). On the other hand, no significant findings were detected on the between-group variance(p>0.05) and the TT level×group interaction (p>0.05). The independent t-test indicated no significant differences in heart rate, oxygen saturation, rating of perceived exertion, and metabolic equivalents at any levels of the TT in the two groups. The TT showed a strong correlation with the rating of perceived exertion. Conclusion: This study showed that the TT is a valid and alternative tool for evaluating the aerobic exercise intensity in a healthy population. In addition, differences in the psychophysiological response markers between two aerobic activities, treadmill and bicycle ergometer, were detected in the same exercise intensity scaled with the TT. The TT can be used to evaluate and prescribe the exercise intensity of aerobic activity in cardiovascular and pulmonary physical therapy.