• The Korean Journal of Nuclear Medicine
• /
• v.32 no.3
• /
• pp.225-237
• /
• 1998

Purpose: We investigated the statistical methods to compose the functional brain map of human working memory and the principal factors that have an effect on the methods for localization. Materials and Methods: Repeated PET scans with successive four tasks, which consist of one control and three different activation tasks, were performed on six right-handed normal volunteers for 2 minutes after bolus injections of 925 MBq $H_2^{15}O$ at the intervals of 30 minutes. Image data were analyzed using SPM96 (Statistical Parametric Mapping) implemented with Matlab (Mathworks Inc., U.S.A.). Images from the same subject were spatially registered and were normalized using linear and nonlinear transformation methods. Significant difference between control and each activation state was estimated at every voxel based on the general linear model. Differences of global counts were removed using analysis of covariance (ANCOVA) with global activity as covariate. Using the mean and variance for each condition which was adjusted using ANCOVA, t-statistics was performed on every voxel To interpret the results more easily, t-values were transformed to the standard Gaussian distribution (Z-score). Results: All the subjects carried out the activation and control tests successfully. Average rate of correct answers was 95%. The numbers of activated blobs were 4 for verbal memory I, 9 for verbal memory II, 9 for visual memory, and 6 for conjunctive activation of these three tasks. The verbal working memory activates predominantly left-sided structures, and the visual memory activates the right hemisphere. Conclusion: We conclude that rCBF PET imaging and statistical parametric mapping method were useful in the localization of the brain regions for verbal and visual working memory.

• Proceedings of the ESK Conference
• /
• 1996.04a
• /
• pp.191-199
• /
• 1996

단순 VDT 작업에 의한 인간의 시각정보처리에의 영향을 살펴보기 위하여 특히 서로 다른 model에 대한 정보처리에의 영향을 조사하였다. 피험자는 시각감시 작업과 데이타입력작업을 각각 50분씩 2회 수행하였고 서로 다른 model에 대한 영향을 살펴보기 위해 적업 전, 중 ,후에 걸쳐 MD 및 PD 방법에 의한 과제가 실 시되었다. 실험결과, 단순 VDT 작업이라고 하더라도 작업 수행 내용의 차이에 따라 서로 다른 model에 대한 정보처리에의 영향이 다르게 나타날 수도 있다는 점이 시사되었다.

• Science of Emotion and Sensibility
• /
• v.6 no.3
• /
• pp.21-28
• /
• 2003

This study investigated the differences in processing type of working memory between experts and novices when they read music scores. Two experiments were conducted with the articulatory suppression condition. In Experiment 1, eight half notes were shown on the screen for a brief period of time, participants were then requested to write the notes on a music sheet. the stimuli were divided into two: melodious and unmelodious. In similar fashion, Experiment 2 consisted of four-chord sequences, which contained three notes each. The stimuli were also divided into two: harmonious and disharmonious. As an analysis of the results in Experiment 1 & 2, novices commonly showed better performances in the non-articulatory suppression condition than the articulatory suppression condition with both stimuli types. However, experts were relatively affected little by the articulatory suppression with harmonious stimuli. These findings support that while novices entirely depend on the articulatory loop, experts may encode the notes through the visuo-spatial sketchpad before they transfer the information to the phonological store when they are familiar with material.

• Journal of Digital Convergence
• /
• v.11 no.3
• /
• pp.363-369
• /
• 2013

In this paper, the modeling of phenomena that occurs in the brain related language was designed and developed the second language proficiency method. This method based on cognitive ability test in cognitive psychology that is the lexical decision task, the priming task and the verbal span task. The lexical decision task involves measuring how quickly decide stimuli as words or nonwords. This task is divided reading and listening according to stimulus type to the details. The priming task finds the output of the language. This task is divided the translation-priming and the semantic-priming according to stimulus type. The verbal span task finds the short term memory. In this paper, we propose the second language proficiency measurement method using the linguistics cognitive ability of the learner about the second language.

• Korean Journal of Cognitive Science
• /
• v.21 no.4
• /
• pp.559-602
• /
• 2010

This study examines the concepts and functional characteristics of consciousness in comparison of memory and attention from the perspective of information processing. It also provides an understanding of the relationships between the three as hypothetical constructs. Consciousness is regarded as too ambiguous a concept to be understood and accepted as a mental construct without the inclusion of memory and attention in any conceptualization. We need one criterion to count satisfactorily as an explanation of consciousness in information processing. Consciousness would be a subjective awareness of momentary experience and also have the characteristic of an operating system performing control and consolidation in information processing. This could be called cognitive consciousness which refers to a subjective awareness and an executive control system, even though those are not equivalent concepts. Consciousness, memory and attention, three mental constructs could operate dependently or independently depending on the specific tasks conditioned in many information processing levels whose modules with three mental constructs could operate in hierarchy. In this premise, working memory could not be a unitary system, contrary to those of Baddeley and Hitch(1974) and Baddeley(1992, 2000), just being a mental workplace consisting of two components: the phonological loop, and the visual-spatial sketchpad without the episodic buffer and a central executive which are the characteristics of consciousness. In the continuum of information processing, the conscious processes and the unconscious processes seem not to be totally different and contrasting processes.

• 한국노년학
• /
• v.36 no.4
• /
• pp.1109-1124
• /
• 2016

We examined the effect of stereotype threat (STT) on spatial working memory and facial emotion recognition in Korean elderly. In addition, we investigated the role of expected moderator such as self-perception of aging. Seventeen seniors (male=7) received basic cognitive tests including K-WMS-IV, MMSE and answered self-report questionnaires including self-perception of aging, anxiety of aging, attitude toward aging and age identity on the first visit. On the second visit, they were exposed to negative stereotype by reading a script detailing cognitive decline related to aging while a control group was exposed to a neutral content. Following the exposure, they were tested on a spatial-working memory task (Corsi-block tapping task) and emotion recognition task (facial expression identification task). The results showed that the seniors exposed to STT showed significantly lower performance on emotion recognition task (p < .05) (i.e., especially on the more difficult facial stimuli). In addition, there was a significant interaction between STT and self-perception of aging (p< .05), indicating that those who have positive self-perception of aging did not show impairment in emotion recognition task and difficult spatial working memory task under STT. On the other hand, those with negative self-perception of aging showed impaired performance under STT. Taken together, the current study suggests that being exposed to STT could negatively influence cognitive and emotional functioning of elderly. Interestingly, having a positive self-perception of aging could protect the underperformance caused by STT.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.34 no.1
• /
• pp.56-64
• /
• 2006

This paper presents the development and application of a conducting shape memory polyurethane (CSMPU) actuator. While conventional shape memory polyurethanes were activated by external heat source, conducting shape memory polyurethanes introduced in 2004 are activated by electric power. Conducting shape memory polyurethane actuators were manufactured by adding carbon nano tube to conventional shape memory polyurethane. The main problem of the CSMPU developed in 2004 was bad dispersion of carbon nano tubes. In this paper, we tried to find how to solve the dispersion problem, and with a lot of elaborative works, conducting shape memory polyurethane actuators which had better electrical characteristics were developed. Then the actuation performance of the conducting shape memory polyurethane actuators was also measured and assessed. Finally, the possibility of applications were examined through the installation to Micro Air Vehicle.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.4
• /
• pp.351-360
• /
• 2016

The purpose of this study is to predict visual-spatial working memory performance through the characteristics of an electroencephalogram (EEG) in the resting state. The 31 study participants, middle school students with various to academic performance, were underwent visual-spatial working memory test in the Comprehensive Attention Test (CAT) on December in 2014. Each 7 and 6 participants were divided into an Excellent Working Memory (EWM) group and Poor Working Memory (PWM) group depending on the forward/backward working memory scores. The EEG measurements and analysis of the data from a Brain Function Tester were performed by the two groups. A Mann-Whitney Test was used to examine the statistical differences between them. The activation of high beta (${\beta}H$) at the Fp1 and Fp2 sites in the left and right hemisphere, and that of the low beta (${\beta}L$) in the right hemisphere in the EWM group was significantly higher than that in the PWM group. In conclusion, there is a correlation between the visual-spatial working memory performance and the activation of ${\beta}H$ and ${\beta}L$ in the resting state and a close correlation that of ${\beta}L$ in the right hemisphere in terms of mental activity and faculty. Therefore, the visual-spatial working memory performance can be predicted by the activation of ${\beta}H$ and ${\beta}L$ in the resting state. The activation of EEG can be applied as an assessment tool and provide basis data for visual-spatial working memory performance.

• Korean Journal of Cognitive Science
• /
• v.23 no.4
• /
• pp.487-515
• /
• 2012

The purpose of this study was to investigate the effect of the individual differences in cognitive processes on paragraph comprehension. To do so, the lexical decision task and the pattern comparison task were used to measure the low-level cognitive processes. Digit span task was used to test the phonological loop capacity. The individual differences of the central executive processing capacity were measured by operational span task. Reading span task was used to test the working memory capacity related with the sentence processing. Reading times and accuracies of the logically valid inferences and logically void inferences were tested to measure the high-level cognitive processes. Reading times and accuracies for the target sentences with and without prior explicit causal sentence were measured to test individuals' paragraph comprehension abilities. The results showed that the speed of the low-level cognitive processes was related with the speed of the high-level cognitive processes. Also, the accuracy of the low-level cognitive processes was related with the accuracy of the high-level cognitive processes while there was no significant correlation between the speed and the accuracy in any measures of the cognitive processes. Working memory capacity was related with the accuracy of the cognitive processes while it was not significantly correlated with the speed of the cognitive processes. Most importantly, the speed of low-level cognitive processes significantly affected the speed of the paragraph comprehension while the working memory capacity and the high-level cognitive processes had influences on the accuracies of the paragraph comprehension. The speed of the paragraph comprehension had no influence on the accuracies of the paragraph comprehension.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
• /
• 2000.04a
• /
• pp.47-52
• /
• 2000

단기기억 작업시 집중도를 평가하기 위하여 평가용 task를 설계하고 5단계의 난이도에 대하여 실험을 실시하였다. 난이도에 따른 집중도의 변화를 측정하기 위하여 주관평가를 실시하고 행동지표와 생리신호를 측정하였다. 측정된 생리신호 중 전두엽(Ep1, Ep2)에서 측정한 뇌전도 신호의 $\alpha$-band와 $\beta$-band의 전력의 비와, 심박변화율의 전력 스펙트럼의 MF/(LF+MF+HF)비를 구하였다. 실험 결과 집중도 높게 보고된 단계에서 task를 수행함에 따라 뇌전도 신호의 $\alpha$/$\beta$ 비와 심박변화율의 MF/(LF+MF+HF) 비도 점차로 증가하였다.