• Journal of Korea Entertainment Industry Association
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• v.13 no.6
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• pp.277-286
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• 2019

The aim of this study was to investigate the effects of computer-based cognitive rehabilitation and traditional cognitive training on the working memory and executive function of patients with mild traumatic brain injury. The sample consisted of 20 patients with mild traumatic brain injury who had received rehabilitation treatment in a rehabilitation unit. The subjects were assigned to either the experimental (n = 10) or control group (n = 10). The experimental group received computer-based cognitive rehabilitation and traditional cognitive training for 60 minutes, whereas the control group received only traditional cognitive training for 60 minutes. Both the groups received their respective interventions for 60 minutes a day and 5 times per week across a period of 4 weeks. Working memory and executive function were assessed using the digit span test (forward and backward), visual memory 1 and 2 of the Motor-free Visual Perception Test-3, trail making test, and Stroop test (A and B) both before and after the intervention. The experimental group showed a significantly greater improvement in visual memory and performance on the Stroop test A than the control group. These findings suggest that computer-based cognitive rehabilitation and traditional cognitive training are more effective in promoting positive changes in the working memory and executive function of individuals with mild traumatic brain injury than traditional cognitive training.

• Science of Emotion and Sensibility
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• v.27 no.2
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• pp.113-126
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• 2024

Individuals with social anxiety disorders tend to hold attentional bias toward threatening stimuli in social contexts regardless of task relevance. Although attentional bias is relatively consistent, findings on memory performance are mixed. This study examined attentional and memory biases toward threat stimuli in individuals with high levels of social anxiety. Participants included 19 individuals with high social anxiety (HSA) and another 20 individuals with low social anxiety (LSA). They performed a continuous attention task to measure attentional bias to threat. Afterward, they performed an unexpected memory task using distracting stimuli from the previous attention task to measure memory bias to task-irrelevant threatening stimuli. The results indicated that the HSA and LSA groups exhibited an initial attentional bias toward emotional faces. However, only the HSA group displayed prolonged attentional bias and demonstrated memory bias toward angry faces. Conversely, the LSA group exhibited attentional bias toward happy faces after 4 s. The findings imply that the absence of bias toward positive stimuli and the presence of bias toward negative stimuli may contribute to the maintenance and severity of social anxiety pathology.

• The Transactions of the Korea Information Processing Society
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• v.3 no.6
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• pp.1407-1417
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• 1996

In recent researches on thread partitioning algorithms break a thread at the long latency operation and merge threads to get the longer threads under the given constraints. Due to this limitation, even a program with little parallelism is partitioned into small-sized threads and context-swithings occur frequently. In the paper, we propose another method array localization about the array name, dependence distance(the difference of accessed element index from loop index), and the element usage that indicates whether element is used or defined. Using this information we can allocate array elements to the node where the corresponding loop activation is executed. By array localization, remote accesses to array elements can be replaced with local accesses to localized array elements. As a resuit,the boundaries of some threads are removed, programs can be partitioned into the larger threads and the number of context switchings reduced.

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

• Annual Conference on Human and Language Technology
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• 1994.11a
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• pp.113-118
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• 1994

한국어 정보처리를 효율적으로 수행하기 위해서는 단어의 검색시간을 최소화하여야 한다. 그러나 기존의 방법들은 단어의 삽입과 삭제가 불가능하거나 검색시간이 길다는 단점을 가지고 있다. 본 논문에서는 탐식시간을 최소화하기 위해서 이중 배열을 가지는 이중 트라이를 이용하여 음절 및 자소단위의 검색방법에 관하여 논의한다. 검색시간에 있어서는 음절단위의 방법이 자소단위의 방법보다 빠르지만 기억장소는 자소단위의 방법이 음절단위의 방법보다 효율적이다. 자소단위의 방법에서 하나의 트라이를 여러개로 분할하여 저장함으로써 기억장소를 절반으로 줄일 수 있어 기억장소를 보다 효율적으로 이용할 수 있다.

• The Journal of Korean Association of Computer Education
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• v.14 no.5
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• pp.39-46
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• 2011

Serious games are designed for special purposes of education, training, treatment as well as game-like fun and entertainment. Recently, domestic and foreign market of serious game are growing rapidly. By dissemination of smartphone, the global market for serious game will be expanded for various purposes and users. In this paper, we design and implement serious game 'QUICK REMEMBER 20' for memory improvement using smartphone. We analyze game users based on socio-demographic characteristics and evaluate the learning effectiveness of this game with statistic method.

• Korean Journal of Cognitive Science
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• v.29 no.3
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• pp.161-192
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• 2018

Retrieving temporal information of encoded events is one of the core control processes in episodic memory. Despite much prior neuroimaging research on episodic retrieval, little is known about how large-scale connectivity patterns are involved in the retrieval of sequentially organized episodes. Task-related functional connectivity multivariate pattern analysis was used to distinguish the different sequential retrieval. In this study, participants performed temporal episodic memory tasks in which they were required to retrieve the encoded items in either the forward or backward direction. While separately parsed local networks did not yield substantial efficiency in classification performance, the large-scale patterns of interactivity across the cortical and sub-cortical brain regions implicated in both the cognitive control of memory and goal-directed cognitive processes encompassing lateral and medial prefrontal regions, inferior parietal lobules, middle temporal gyrus, and caudate yielded high discriminative power in classification of temporal retrieval processes. These findings demonstrate that mnemonic control processes across cortical and subcortical regions are recruited to re-experience temporally-linked series of memoranda in episodic memory and are mirrored in the qualitatively distinct global network patterns of functional connectivity.

• Journal of Life Science
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• v.19 no.3
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• pp.403-410
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• 2009

This study investigated the effects of treadmill exercise on memory ability, cell proliferation, BDNF, and TrkB in the hippocampus and forebrain cholinergic cells in adolescent rats. Male Sprague-Dawley rats (4 weeks old) were randomly assigned to the following two groups: the sedentary group (n=10) and the exercise group (n=10). Rats in the exercise group were forced to run on a treadmill for 30 min, five times per week for 4 weeks. The latency of the step-through avoidance task was used in order to evaluate memory ability. Hippocampal brain-derived neurotrophic factor (BDNF) and tropomyosin-related kinase B (TrkB) expression were assessed by Western blotting. Hippocampal cell proliferation and forebrain cholinergic cells were assessed by immunohistochemistry. The present study showed that treadmill running during the adolescent period significantly improved memory capability, increased hippocampal cell proliferation, up-regulated hippocampal BDNF and TrkB expression, and enhanced the number of forebrain cholinergic cells. These results suggest that regular exercise during the adolescent period may enhance memory function.

• Korean Journal of Culture and Social Issue
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• v.18 no.2
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• pp.215-234
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• 2012

The purpose of this study was to explore linkages between stress and a range of individual difference factors on children's memory for a potentially stressful event. Children (N=63) aged from 4 to 10 years, who undergone a minor dental operative procedure were evaluated. Overall, the results of this study replicated and extended previous findings of the related literature, providing some further evidence for a negative relation between stress and children's recall. More considerable variation in individual difference variables, in particular, children 's stress coping strategies, quality of previous experiences, amount of the advanced parental preparation were existed among the children, influencing the relation between the level of stress and children's remembering of a stressful event. Future inquiries for understanding theoretical, clinical, and forensic issues in children's remembering of a stressful event were discussed.

• Progress in Medical Physics
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• v.21 no.1
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• pp.42-51
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• 2010

Imaging studies using MRI, PET, and/or MEG have been primary evaluation methods to quantitatively assess cognitive function. Recent advances in computational technology and information technology may allow a novel evaluation methodology to quantitate cognitive function more cost-effectively. In this study, we developed a software package composed of a series of tests to evaluate cognitive ability combined with a user-friendly touch screen input device. This cognitive assessment tool can quantitate concentration, numeric memory, associative memory, topological memory, visual and muscular reaction, and acoustic reaction over a relatively short testing time. We performed an empirical study on eighty normal subjects aged 20 and 59 years old using the developed evaluation methods. Age-related cognitive deterioration after 40 years old was confirmed. There was no difference in cognitive ability between male and female in the same age group. This study demonstrates the feasibility of a simple but effective evaluation software tool to quantitatively assess cognitive ability. This methodology may provide improved accessibility and reduced costs to perform cognitive function studies to compare between various subject groups.