• 한국안전학회지
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• 제26권3호
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• pp.83-90
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• 2011

It is well known that urgency resulted from time stress can be a great cause to industrial accidents. Therefore, time stress has been studied in the aspect of macroscopic view, namely industrial safety management, but has not been studied in microscopic view such as psychophysiological approach. Among diverse psychophysiological indices, Electroencephalogram(EEG) would be on of the most objective psychophysiological research technique on human errors though few research has been taken yet. This study aimed to get characteristics of human error while committing a simple arithmetic addition task by utilizing the power spectrum technique of EEG data. Each experiment was composed of 2 tasks under different condition - with and without time stress. As subjects, 5 young undergraduate students in their early twenties participated in this study. The results advocated a well-known fact that time stress downgrades the performance of human workers. However, correct answer rate and response time were not significantly influenced by time stress factor which might be explained by the constructural factor adopted in the present study. As in the previous studies, among various EEG-related measures, relative band power ratios of ${\alpha}$ and ${\beta}$ waves to sum of ${\alpha}$,${\beta}$,${\theta}$ wave powers, namely $P_{{\alpha}/({\alpha}+{\beta}+{\theta})}$ and $P_{{\beta}/({\alpha}+{\beta}+{\theta})}$ seemed to be the most effective measures to grasp variation of brain activities in time-stressed situation so that discussions were expanded about their variations.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1999년도 학술발표대회 논문집 제18권 1호
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• pp.263-268
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• 1999

Psychoacoustic characteristics of automobile hems influence subject's subjective evaluation and psychophysiological reactions on the sounds of car horns. However, differentiation of physiological responses to commercially availablenfluence subject's subjective evaluation and psychophysiological reactions on the s horns is a complicated task due to the small contrast in technical features of horns and the influence of habituation. Using 10 college students, comparative analysis of physiological reactivity was carried out in order to identify the effect of habituation on decrement of psychophysiological responsivity, assess the ability to differentiate subjectively most and least preferred/appropriate horns according to physiological manifestations. EEG and autonomic responses to 7 automobile horns were analyzed during 3 blocks of trials (each block was varied in order for presenting stimuli and acoustic parameters of horns). It was shown that electrodermal and cardiovascular responses had different reactivity patterns to repeated stimulation. Skin conductance variables (SCL, SCR) were habituated as a function of trial. Cardiac reactivity (HR, RSA) showed no signs of habituation. In contrast, sensitization was shown in the vascular component of response (pulse volume). The temporal EEG exhibited marked habituation of fast beta band power, while alpha-blocking effect did not habituate during the course of experiment. Differentiation of physiological responses of most and least preferred/appropriate horns was possible in this study. That is, some cardiovascular reactivity variables (HR, RSA, pulse volume, etc.) were differentiated between the least and the most preferred/appropriate horns during the experiment. However, EEG and electrodermal parameters showed significant differences only during first block of trials and were later affected by habituation.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1999년도 학술발표대회 논문집 제18권 1호
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• pp.269-273
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• 1999

Combination of mental stress task with noise background is a traditional tool employed in psychophysiology. However, intensity of background noise is a factor affecting both performance on test and psychophysiological responses associated with stress evoked by mental load in noisy environment. In the current study on 7 subjects we analyzed the influence of white noise (WN) intensity (55, 70, and 85 dB[A] ) on psychophysiological responses during word recognition test performed on noise background. There were recorded following physiological variables: electrodermal activity (EDA) , namely, skin conductance level (SCL), skin conductance response (SCR) amplitude (SCR-A), rise time and total number of SCRs (N-SCR); cardiovascular activity, e.g., heart rate (HR), respiratory sinus arrhythmia (RSA) index, pulse transit time (PTT), finger pulse volume (PV), skin temperature (SKT) and respiratory activity, such as respiration rate (RESP-R) and inspiration wane amplitude (RESP-A) during baseline resting state and 40 s long performance on 3 similar Korean word recognition tests with different WN intensity (55, 70, and 85 dB). Electrodermal responses (SCR-A, SCL, N-SCR) demonstrated gradual increment with increased intensity of noise, and this increase of response magnitude with higher intensity of noise was typical also for r skin temperature (phasic SKT decrease) and pulse volume (phasic and tonic PV decrease). However, some cardiovascular and respiratory responses did not exhibit same tendency of gradual increase of reactivity , namely HR, as well as RESP-R and RESP-A showed decrement of response magnitudes. Important finding in terms of cardiovascular reactivity was that 55 and 70dB evoked similar profiles, while 85dB WN resulted in significantly different profile of reactions, suggesting that there exists a threshold level after which intensive auditory stimulation elicits psychophyslological responses pattern of different quality. There are discussed potential autonomic mechanism involved in mediation of observed physiological responses.

• 감성과학
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• 제21권1호
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• pp.45-58
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• 2018

As information and communication technologies (ICTs) become more advanced, consumers are able to experience retailing activities such as searching for products and services in online retail shops and for Internet-exclusive branded contents. Specifically, fashion retailers are facing the need to develop more novel experiential design than one another to maximize customers' experience in Internet websites and secure sustainable competency. Confirming methods of organic integration of experiential and visual features of both online and mobile channels is an important aspect of the study of extended consumers' interfaces of retail channels. Mehrabian and Russell's stimulus-organism-response (S-O-R) paradigm and Sugiyama and Andree's attention, interest, search, action, and share (AISAS) model were used for this research. Specifically, the present study considered the effect of e-commerce website features on consumers' emotional reactions (pleasure and arousal) and the consequent impact on online consumer behaviors (search, action, and share). Hence, plus the self-reported survey methods, each subject's psychophysiological indicators (i.e., pleasure and arousal) were measured to obtain more objective and reliable data and to redeem the results of the self-reported survey. Findings revealed the implications of the e-commerce website feature by comprehending the S-O-R paradigm and AISAS model and extending the understanding of the role of variables associated with comprehended frameworks based on psychophysiological data.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 1999년도 춘계학술발표논문집 논문집
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• pp.221-230
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• 1999

Automobile horn's psychoacoustic characteristic and significance as a anturalistic signal of danger makes it a valuable auditory stimulus to study such psychophysiological responses as startle, orienting and defense reactions. However, comparison and differentiation of physiological responses to commercially available horns is a complicated task due to small contrast of technical features of horns and influence of such processes as habituation on physiological outcome with increased number of auditory stimulation trials. In the study on 10 college students we performed comparative analysis of tonic and phasic reactivity of physiological responses mediated by autonomic nervous system in order to identify role of habituation and decrement of autonomic responsivity, as well as possibility o differentiate subjectively most and least preferred and subjectively more appropriate horns according to physiological manifestations. It was showed that electrodermal and cardiovascular reactivity have concurrent patterns of adaptation to repeated stimulation, namely skin conductance variables habituated, cardiac reactivity failed to show signs of habituation, while vascular component of response were facilitated demonstrating marked sensitization. Differentiation of Physiological responses to horns with respect to their subjective rating scores was possible, however electrodermal reactivity was effective only at the first block of trials, while phasic and tonic cardiovascular reactivity differentiate responses during whole course of experiment. There are discussed possible autonomic mechanisms involved in mediation of observed results.

• 한국안전학회지
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• 제15권1호
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• pp.167-175
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• 2000

Work performance and human error are complicated phenomena so that it is very difficult to grasp the true nature of them. However, Event Related Potential (ERP) may give a clue to them because human brain reflects diverse psychophysiological process. In the present study, the possibility of ERP application to the ergonomic area was evaluated in view of grasping error symptoms. For that purpose, the subjects were asked to count specific characters in a random character matrix on a computer monitor, and their ERP was compared with their performance data. Based upon the results, the amplitude of P300 was not so high as that in the case of the Odd Ball tasks, correct response corresponded with stable ERP with high P300 amplitude whereas wrong response did with unstable, fluctuating ERP with low P300 amplitude. Those results coincided with the work performance, and it was concluded that 3-wave fluorescent with illumination level of 800 lux would be recommendable for the counting task in concern. Conclusively, ERP including P300 might supply an objective clue to the problem of human errors in cognitive process.

• 감성과학
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• 제3권2호
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• pp.17-28
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• 2000

Psychoacoustic characteristics of automobile horns play significant role in resulting subjective evaluation and psychphysiological reactions. However, comparison and differentiation of physiological responses to commercially available horns is a complicated task due to the small contrast in technical features of horns and the influence of such processes as habituation on physiological outcome with the increased number of auditory stimulation trials. In a study on 10 college students, there was performed comparative analysis of reactivity of physiological responses mediated by central and autonomic nervous systems in order to identify the role of habituation on decrement of psychophysiological responsivity and assess the ability to differentiate subjectively most and least preferred, as well as most and least appropriate horns according to physiological manifestations. The EEG and autonomic responses to 7 automobile horns were analyzed during 3 blocks of trials, with varying order of stimuli and changed acoustic parameters of horns in each block. Thus, responses were analyzed for totally 21 trials of auditory stimulation. It was shown that electrodermal and cardiovascular responses have different reactivity patterns to repeated stimulation: skin conductance measures habituated, cardiac reactivity showed no signs of habituation, and the vascular response demonstrated sensitization. The temporal EEG exhibited marked habituation of fast beta band power, while alpha-blocking effect did not habituate during the course of experiment. Differentiation of physiological responses of most and least preferred and appropriate horns was possible in our study, however, some cardiovascular reactivity measures differentiated during the entire course of the experiment, while EEG and electrodermal parameters showed significant differences only during first block of trials, and were later affected by the habituation.

• 감성과학
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• 제5권4호
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• pp.51-57
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• 2002

자동차 시뮬레이터에서 운전 형태에 따른 감성을 평가하기 위하여 운전자의 심리생리적 반응을 측정하였다. 운전 형태는 정차, 정속주행(70km/h), 급출발(0km/h$\longrightarrow$70km/h)및 급제동(70km/h$\longrightarrow$0km/h)으로 하였다. 피험자는 운전경력이 1년 이상인 20대 남자 12명을 대상으로 Simulator Sickness 및 주관적 쾌적감과 각성감, 뇌파(Electroencep-halogram), 심전도(Electrocardiogram), 피부온도(Skin temperature), 피부전기저항(Galvanic skin response)을 측정하였다. 주관적, 생리적 평가는 각 주행조건에서 주행 전과 후에 실시하였다. 실험결과 정차 및 정속 주행보다 급출발 및 급제동 조건에서 쾌적감과 각성감은 높아졌다. 생리적으로는 정차 및 정속 주행보다 급출발 및 급제동 조건에서 중추신경 반응은 알파파가 감소하였고, 베타파는 증가하였다. 자율신경 반응은 심박율 및 피부전기저항의 증가, 피부온도의 저하로부터 교감신경이 활성화됨을 알 수 있었다. 이러한 결과로부터 운전 형태에 따라 심리 .생리적인 변화가 뚜렷하였고, 시뮬레이터를 이용한 동적 환경에서의 감성 평가가 가능하였다. 감성에 대한 개인간의 차이를 최소화하고 객관화된 감성을 도출하기 위해서는 앞으로 더 많은 대상자에 대한 측정 자료가 요구된다.

• 대한인간공학회지
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• 제32권6호
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• pp.481-487
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• 2013

Objective: The present study aims to evaluate the visual reactions of users when they are playing games of different flow levels, and to explore the visual variables that can sensitively reflect the different flow levels. Background: The flow is defined as a psychological state where interface users feel their actions in a virtual setting identical to those in real environment. To measure the flow states of users, the questionnaire-based FSS(Flow State Scale) has mostly been used. However, this method is a qualitative test that has limits in terms of the accuracy of users' flow experiences. Therefore, more accurate methods to measure users' flow experiences are required. Method: Ten subjects participated in the experiment, where the independent variables were three games with different flow levels(puzzle games, dot drawing and coloring) and the time frame(the first and last 10 seconds in game playing), whereas the dependent variables included the pupil size and the frequency and duration of eye blinking. This study was a within-subject design. Each participant performed three types of games with different flow levels 3 times for each for 10 minutes, and their visual reactions to each game were measured. Results: The higher the flow cause the bigger pupil size(p<0.01) and the lower eye blinking frequency(p<0.1), indicating that different types of games lead to different flow levels. The pupil size during the last 10 seconds when the flow level was higher was bigger by 2.1% compared with that during the first 10 seconds in game playing(p<0.1), and the eye blinking frequency decreased by 12%(p<0.01). Conclusion: It was found out that the pupil size and the frequency and duration of eye blinking were psychophysiological indices for evaluating users' flow experiences, which could quantify the flow states users go through. The psychophysiological variables capable of measuring diverse aspects of the flow need diversifying to be applicable to precise measurement of the flow. Application: These studies are warranted for both quantitative analysis of flow levels and qualitative improvement of cyber leisure in line with development of healthy games.

• 감성과학
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• 제6권3호
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• pp.13-20
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• 2003

본 실험은 자동차 시뮬레이터의 속도 변화(40, 70, 100km/h)와 롤러코스터 시뮬레이터의 운동성 구현 방법(washout 필터 적용, washout 필터 비적용)에 따른 인간 감성을 탑승자의 심리ㆍ생리적 반응을 통하여 비교 평가하였다. 자동차 시뮬레이터, 롤러코스터 시뮬레이터에 각각 건강한 20대 남자 12명, 8명을 대상으로 simulator sickness, 쾌적감, 긴장감, 각성감, 속도감에 대한 주관적 평가 및 생리신호로 뇌파의 변동리듬, 심전도, 피부전기저항을 주행 전후에서 측정하였다. 결과, 자동차 시뮬레이터에서의 저속 주행보다 운동 형태가 다양한 롤러코스터 시뮬레이터 주행시 쾌적감, 긴장감, 각성감, 속도감, 뇌파 변동리듬을 통한 쾌적도가 높았다. 뇌파의 알파파 대역의 평균 주파수는 롤러코스터 주행보다 자동차 주행에서 더 높았고, 심박률과 피부전기저항은 각 주행조건에서 주행 전후간 유의하게 변화하였다. 이상에서 주행 속도의 증가, 다양한 운동 형태의 시뮬레이터 주행시 주관적 감성은 높았고, 생리적 반응은 주행 속도 증가에 따라 활성화됨을 알 수 있었다.