• Science of Emotion and Sensibility
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• v.20 no.1
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• pp.115-132
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• 2017

Differences in reaction time and accuracy were compared among driver groups of middle-, old-, and stroke old-age drivers using various reaction time tasks including simple reaction task, 2-choice task, 4-choice task with different stimuli eccentricity, search task, and moving target detection task. The results can be summarized as followings. First, although overall reaction time tended to be slowed with age and stroke, stroke old drivers showed significantly slower reaction time than the other driver groups when the stimuli were presented in a large eccentricity. Second, differences in reaction time for 2-choice task and moving target detection task seemed to be determined mainly by participants' simple reaction time. Third, the search task which required temporary retention of previously presented stimuli was found to be more sensitive in discriminating difference in reaction time between middle-age drivers and old-age drivers (including stroke old drivers). Fourth, reaction accuracy of old (and stroke old) drivers decreased when more stimuli alternatives were presented and temporary retention for stimuli was required. Altogether, memory demand in reaction time task can be sensitive to evaluate performance for different age groups, whereas size of useful field of view for brain stroke.

• Science of Emotion and Sensibility
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• v.17 no.2
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• pp.63-76
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• 2014

Although most behavioral reaction times (RTs) for cognitive tasks exhibit positively skewed distributions, the majority of studies primarily rely on a measure of central tendency (e.g. mean) which can cause misinterpretations of data's underlying property. The purpose of current study is to introduce procedures for describing characteristics of RT distributions, thereby effectively examine the influence of experimental manipulations. On the basis of assumption that RT distribution can be represented as a convolution of Gaussian and exponential variables, we fitted the ex-Gaussian function under a maximum-likelihood method. The ex-Gaussian function provides quantitative parameters of distributional properties and the probability density functions. Here we exemplified distributional analysis by using empirical RT data from two conventional visual search tasks, and attempted theoretical interpretation for setsize effect leading proportional mean RT delays. We believe that distributional RT analysis with a mathematical function beyond the central tendency estimates could provide insights into various theoretical and individual difference studies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.3
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• pp.1114-1121
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• 2012

There is a cause and effect relationship in that brain injury causes impairment of mental rotation and ultimately independent functional activities. The purpose of this study was to compare the effects of mental rotation on reaction time and precision between the normal adults and chronic hemiparetic stroke patients. Thirty-one patients with chronic hemiparetic stroke and twenty normal adults participated in this study. The participants conducted 2 types of tasks for mental rotation: a comparison task using mirror images, and a rotation task using angular disparity images for 2 different 3-dimensional objects. Each of the 3 possible angled shapes ($90^{\circ}$, $180^{\circ}$, and $270^{\circ}$) appeared in each pair. The test consisted of 6 mirror-reflected image pairs and 6 angular disparity image pairs visualized during angular rotation, and 12 test periods. The subjects were judged on how accurately and rapidly they could distinguish between the mirrored and non-mirrored pairs. The study measured reaction time and precision to compare the effect of mental rotation tasks. Reaction time during all 3 angular conditions were significantly longer in the stroke patients than that in the normal adult during the comparison tasks and the rotation tasks. In addition, precision during mental rotation tasks was not significantly different between normal adults and stroke patients. Our results suggest that rehabilitation therapists should keep in mind that mental rotation is more difficult in stroke population than in normal adults.

• 재활복지
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• v.20 no.4
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• pp.229-246
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• 2016

The aim of this study is to conduct superordinate word selection task to compare their performance and reaction time, and superordinate word writing task to compare the differences in their performance and error pattern in 40 elderly adults and 43 young adults. As a result, first, in both tasks, elderly adults had a smaller number of correct responses. Second, elderly adults showed slower reaction time than young adults. Third, in superordinate word writing task, elderly adults showed more relevant errors than irrelevant errors. The reason elderly adults had a smaller number of correct responses in both tasks was that the links among the pieces of information in the semantic lexicon weakened or deteriorated due to normal aging. Slower reaction time was based on neurophysiological changes of the brain and cognitive processing speed. In addition, the relevant errors showed that they could access the lexicon for target words and produce explanation the relevant characteristics, even though they could not retrieve the target words.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2001.11a
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• pp.255-259
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• 2001

본 연구에서는 긍/부정 판단 과제 시 연령간 뇌파 반응의 차이를 밝히고자 한다. 실험 대상의 연령은 10명(20대 5명, 60대 5명)이었으며, 모두 오른손잡이였다. 실험과제는 의미과제와 일화과제로 구분되며 각각 12문항으로 구성된다. 의미기억과제 덧셈문제를, 일화기억 과제는 도형을 이용하였으며, 마우스 버튼을 눌러 긍/부정 판단 반응을 하도록 하였다. 뇌파는 PE1, PF2, F3, F4, O1, O2에서 단극유도법으로 측정되었으며, EOG를 측정하여 뇌파분석 시에 눈 깜박임으로 인하 noise를 제거하도록 하였다. 뇌파 분석은 원자료를 FFT(Fast Fourier Transformation)를 수행하여 각 대역의 상대적인 power를 구하는 방법으로 이루어졌다. 분석 결과, 반응 시간은 긍/부정판단간의 차이는 없었으나, 두 과제 모두에서 연령별로 유의미한 차이가 있었다. 긍/부정판단간의 따른 뇌파 반응은 명확한 차이가 나타나지 않았다. 연령에 따른 뇌파반응은 theta파, slow beta, fast beta에서 유의한 차이가 나타났다.

• Korean Journal of Cognitive Science
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• v.20 no.1
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• pp.29-49
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• 2009

The purpose of the present research was to examine whether the parietal pathway and the temporal pathway were responsible for the phenomena of the inhibition of return and the facilitation of return respectively and at what stage of the information processing they occurred. The response time and the ERPs(event-related potentials) were examined in the two conditions(the valid condition and the invalid condition) while subjects were doing detection task, location discrimination task, color discrimination task and orientation discrimination task in separate sessions. No significant response time difference was found between the valid and the invalid conditions when subjects did the detection task as well as the location discrimination task. However, significant response time difference was found when they did the color discrimination as well as the orientation discrimination task. Futhermore, there was a significant difference of ERP difference between the two conditions in the Pz area when subjects were doing location discrimination task and significant difference was found in the T7 area when they were doing color discrimination task and marginal difference was found in T7/T8 area when they were doing orientation discrimination task just before they responded. These results imply the possibility that both the inhibition of return and the facilitation of return occur in the parietal and in the temporal pathway respectively in the late stage of information processing.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2002.05a
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• pp.278-285
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• 2002

본 논문에서는 인지적 긍정/부정 선택 과제의 수행 시 뇌파를 이용하여 피험자의 반응시간 RT를 감지하는 방법에 관하여 기술한다. 실험 Task에서 피험자는 시각적 자극에 대한 반응, 문제의 해석, 손 움직임의 조절, 손동작 등과 같은 작업을 수행한다. 이와 같은 상황에서의 피험자의 정신상태의 변화를 모델링하고, 선택시간 ST를 감지하여 피험자의 반응시간 RT를 예측한다. ST를 감지하기 위하여 측정한 뇌파로부터 $\alpha$, $\beta$, ${\gamma}$파를 분리하고, 4쌍의 전극들로부터 3가지의 특징들을 추출한다. 추출한 특징들을 분석하여 각 피험자별로 나타나는 상세 규칙과 공통적인 특성인 일반 규칙들을 설정하고 이들을 적용한다. 4명의 피험자를 대상으로 평균 81%의 ST 감지 성공률을 보이고, ST 감지 이후 약 0.73초에서 RT가 나타나는 것을 보인다. 본 논문에서 제안한 방법을 기존의 인지적인 정신상태 판별을 위한 방법들이나 왼손/오른손 동작구분 방법들과 결합하여 사용할 경우 BCI를 위한 기반 기술로 활용될 것으로 기대한다.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2009.05a
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• pp.75-78
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• 2009

본 연구에서는 세 가지의 각성상태(긴장, 중립, 이완감정)가 3-back 과제 수행능력에 어떠한 영향을 미치는지 관찰하고자 한다. 10명의 남자 (평균 $25.7{\pm}1.5$ 세) 대학생과 10명의 여자 (평균 $24.5{\pm}1.8$ 세) 대학생이 본 실험에 참여하였다. 집단 검사를 통해 추출된 사진을 이용하여 긴장, 중립, 이완의 세 종류의 각성상태를 유발하여 3-back 과제 수행 능력 측정 실험을 수행하였다. Rest 1 (2분), 감성유발사진제시 1 (2분), 3-back Task 1 (2분), 감성유발사진제시 2 (2분), 3-back Task2 (2분), Rest2 (2분)의 5단계로 실험이 진행되었다. 또한 제시된 감정 사진으로 적절한 arousal level 이 유발되었는지를 확인하기 위해 GSR 신호를 측정하였고, 실험 종료 후 주관적 평가를 실시하였다. 3-back 과제의 정답률은 중립감정일 때 가장 컸고, 이완, 긴장 감정 순서였다. 또한 통계적으로 유의하지는 않았지만 중립감정일 때 반응시간이 가장 빠른 경향을 보였다. 본 연구결과로부터 인지 처리와 무관하게 유발된 각성의 증가나 감소는 과제 수행능력을 감소시킬 수 있다는 사실을 유추할 수 있다.

• Science of Emotion and Sensibility
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• v.13 no.1
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• pp.129-146
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• 2010

System response times(SRTs) are getting important while increasing the function of system. In the past, most research studied SRTs on situation of computer usage. There are lacking the research on simple domain. This study focuses on behavioral and emotional effect on situation of cell phone usage(experience 1; independent variables: degree of SRTs, dependent variables: behavioral and emotional evaluation). And this study investigates the behavioral and emotional effect in same SRTs on different situation(experience 2; independent variables: degree of SRTs, usage mode, dependent variables: behavioral and emotional evaluation, stress, mental strain). The result indicated that long SRTs increased problem solving time and negative emotion. User evaluated the system differently according to usage mode after they performed the same task. In other word, if user had a strong goal, then they felt more negative emotion and mental effort than the user don't have a strong goal. In the goal mode group, it was important there are being of delay or not. This study demonstrated that SRTs and usage mode influence user's emotion and behavior performance in same task.

• The Journal of the Korea Contents Association
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• v.18 no.11
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• pp.484-492
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• 2018

This study examined the effects of field complexity and type of target objects on the performance in baggage screening task. A total of 62 participants(male: 45.2%, female: 54.8%) participated and their mean age was 22.88. The simulated baggage screening task was developed for this study and after the orientation and task exercises, main experiment session was conducted. Participants performed a total of 200 tasks and 40(20%) contained target object. The complexity was set at three levels: high, middle, and low levels and the number of background items contained 20, 14. and 8 respectively. The type of target was set as gun, knife, liquid, and righter. The dependent variables were hit ratio and reaction time. The results showed that the hit ratio decreased and reaction time increased significantly as field complexity increased, and they varied depending on the type of target. The hit ratio of the knife was the highest and liquid lowest and reaction time of the knife was the fastest and liquid slowest. In addition, the interaction effect was also significant. Knife was not affected by complexity, however, small item such as lighter was most affected by complexity.