• Korean Journal of Cognitive Science
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• v.26 no.1
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• pp.27-51
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• 2015

The present study tested the effect of a top-down influence on recalling the colors of Stroop words. Participants remembered the colors of 1, 2, 3 or 6 Stroop words. After 1 second of a memory delay, they were asked to recall the color of a cued Stroop word by selecting out its corresponding color on a color-wheel stimulus. The correct recall was defined when the participants chose a color that was within ${\pm}45^{\circ}$ from the exact location of Stroop word's color on the color-wheel. Otherwise, the recall was defined as incorrect. The analyses of the frequency distribution of the participants' responses in the error trials showed that the probability of choosing the color-name of the target Stroop word was higher than the probability of other five color-names on the color-wheel. Further analyses showed that increasing the number of Stroop words to manipulate memory load did not affect the probability of the Stroop interference. These results indicate that the top-down interference by Stroop manipulation may induce systematic distortion of the stored representation in visual working memory.

• Dementia and Neurocognitive Disorders
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• v.22 no.4
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• pp.148-157
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• 2023

Background and Purpose: Episodic memory is a system that receives and stores information about temporally dated episodes and their interrelations. Our study aimed to investigate the relevance of episodic memory to time perception, with a specific focus on simultaneity/order judgment. Methods: Experiment 1 employed the simultaneity judgment task to discern differences in time perception between patients with mild cognitive impairment or dementia, and age-matched normals. A mathematical analysis capable of estimating subjects' time processing was utilized to identify the sensory and decisional components of temporal order and simultaneity judgment. Experiment 2 examined how differences in temporal perception relate to performance in temporal order memory, in which time delays play a critical role. Results: The temporal decision windows for both temporal order and simultaneity judgments exhibited marginal differences between patients with episodic memory impairment, and their healthy counterparts (p = 0.15, t(22) = 1.34). These temporal decision windows may be linked to the temporal separation of events in episodic memory (Pearson's ρ = -0.53, p = 0.05). Conclusions: Based on our findings, the frequency of visual events accumulated and encoded in the working memory system in the patients' and normal group appears to be approximately (5.7 and 11.2) Hz, respectively. According to the internal clock model, a lower frequency of event pulses tends to result in underestimation of event duration, which phenomenon might be linked to the observed time distortions in patients with dementia.

• Korean Journal of Cognitive Science
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• v.18 no.2
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• pp.159-178
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• 2007

Lee & Kang (2002) showed that simultaneous phonological rehearsal significantly delayed the performance of multiplication but not subtraction, whereas holding an image in the memory delayed subtraction but not multiplication. This result indicated that arithmetic function is related to working memory in a subsystem-specific manner. The aim of the current study was to examine the neural correlates of previous finding using fMRI. For this goal, dual task conditions that required suppression or no suppression were manipulated. In general, several areas were more activated in the interference conditions than in the less interference conditions, although both conditions were dual condition. More important finding is that the specific areas activated in the phonological suppression rendition were right inferior frontal gyrus, left angular, and inferior parietal lobule, while the areas activated in the other condition were mainly in the right superior temporal gyrus and anterior cingulate gyrus. Furthermore, the areas activated in the phonological or visual less suppression condition were right medial frontal gyrus, left middle frontal gyrus, and bilateral medial frontal gyri, anterior cingulate cortices, and parahippocampal gyri, respectively. These results revealed that sharing the processing code invokes interference, and its neural basis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.3
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• pp.1442-1447
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• 2014

This study examined the effect of the cold-warm color contrast of the learning-item on the learner's performance. To do this, experimental conditions were divided into three conditions: control condition, cold-warm contrast condition of background and figure, and cold-warm contrast condition of distracter and target. In addition, the OSPAN (operation span) task was used as the learning task. As a result, the rate of word recognition was higher in cold-warm contrast condition of distractor and target than any other condition. These results could be interpreted as enhancing effect.

• Progress in Medical Physics
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• v.26 no.2
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• pp.72-78
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• 2015

Organic solvents are known toxic effects like vertigo, behavioral obstacle, distracting, and peripheral neuropathy in neuron areas. However, there have been few studies how neurotoxic solvents-exposed workers are affected by the cognitive load of preceding working memory tasks. Therefore, we used fMRI as to measure the neural correlates of working memory impairment in occupational workers who had from chronic exposure to organic solvent. Twenty-nine solvent-exposed workers were included in this study. Each participant concluded the verbal N-back tasks (1- and 2-back) during the fMRI acquisition. Within-group analyses showed fronto-parietal networks were active in each condition. Direct comparisons between 1- and 2-back showed higher activation during the 2-back than 1-back. We found that increased activation of these regions at lower task demand is associated with increased cost of implementing.

• Korean Journal of Culture and Social Issue
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• v.22 no.1
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• pp.41-64
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• 2016

In two experiments, we compared envy with admiration in attentional and motivational benefits. In addition, we tested whether individual differences in working memory capacity (WMC) have consequences for emotion regulation. In Study 1, following WMC tasks, the participants were primed either with envy or with admiration through a recall task, in which they had to recall their own experiences about envy or admiration. The participants in the envy condition considered it more undeserved that another person had an advantage over them, than in the admiration condition. Additionally, in the envy condition, WMC was related to happiness, and anxiety was related to the motivation to study more. In contrast, there were no significant relationships between WMC, emotion and study hours in the admiration condition. Study 2 (N=43) found greater memory for the envy scenario in the envy condition than in the admiration and in the control condition. Additionally, there were significant relationships between WMC, anxiety and recall accuracy in the envy condition. However, these relations were not found in the admiration and in the control condition. Findings implicate that envy may play an important role in memory systems and that WMC is related to emotion regulation abilities.

• Food Science of Animal Resources
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• v.29 no.2
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• pp.278-282
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• 2009

Previous studies indicate that BF-7 enhances learning and memory in normal and elderly individuals. Here, we evaluated whether milk containing BF-7 (BF-7 milk) could improve the brain function, with thirty normal university students $(21{\pm}1.2 years)$. Two versions of the Paced Auditory Serial Addition Test were used under double-blinded conditions to measure the efficacy of BF-7 milk on learning and memory, especially working memory and attention, and on mathematical ability. As a result, BF-7 milk improved the accuracy of the task more than 3-fold. Furthermore, BF-7 milk protected cultured neuronal cells from 3-hydroxykynurenine, a normal endogenous brain stress agent. These results indicate that BF-7 milk enhances memory, attention and mathematical ability in normal persons.

• Korean Journal of Cognitive Science
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• v.22 no.4
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• pp.365-384
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• 2011

A recent study of visual working memory(VWM) under a change detection paradigm proposed an idea that the comparison process of VWM representations against incoming perceptual inputs can be performed more rapidly than the process of forming durable memory representations into VWM. To test this hypothesis, we compared the size of interference effect caused by pattern-backward masks following after either the sample(sample-mask condition) or test items (test-mask condition). In Experiment 1, subjects performed a color change detection task for four colored-boxes, and pattern masks with mask-onset asynchronies(MSOA) of either 64ms or 150ms followed each item location either after the sample or after the test items. The change detection accuracy was both comparable in the sample-mask condition regardless of the MSOAs, whereas the accuracy in the trials with a MSOA of 150ms was substantially higher than the MSOA of 65ms in the test-masking condition. In Experiment 2, we manipulated setsizes to 1, 2, 3, 4 items and also MSOAs to 117ms, 234ms, 350ms, 484ms and compared the pattern of interference across a variety of setsize and MSOA conditions. The sample-mask condition yielded a pattern of masking interference which became more evident as the setsize increases and as the MSOA was shorter. However, this pattern of interference was less apparent in the test-mask condition. These results indicate that the comparison process between remembered items in VWM and perceptual inputs is less vulnerable to interference from pattern-backward masking than VWM consolidation is, and thus support for the recent idea that the comparison process in VWM can be performed very fast and accurately.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.2
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• pp.681-687
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• 2013

This study examined whether the combination of the indoor temperature on the learning environment and the colors of the learning materials affect the learning performance. To do this, the condition of indoor temperature was divided into three conditions: the neutral condition which is the appropriate temperature condition of the learning activities ($22.5{\sim}24^{\circ}C$), the high-temperature condition (> $24^{\circ}C$), and the low-temperature condition (< $22.5^{\circ}C$). In addition, colors of red, blue, black, and green were used as the warm, cold, and neutral colors, and the verbal-working memory task was used as the learning task. As a result, it was not significant differences in the response time of the learning task, whereas, in the accuracy rate of the learning task, the performance was more accurate in red- and black-color conditions. These results could be interpreted as the saliency and color-temperature of the red color, and the familiarity and specificity of the black color.

• Korean Journal of Childcare and Education
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• v.11 no.5
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• pp.135-151
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• 2015

The purpose of this study was to investigate the relationship between preschoolers' motor proficiency and their executive function. Participants were 72 children who participated in individual tests. Motor proficiency was measured by a shortened form of the Bruininks-Oseretsky Test of Motor Proficiency Second Edition(BOT-2). Executive functions were assessed by utilizing the revised version of the four tasks: 'Day-Night Task', 'Dimensional Change Card Sort Task', 'Lift Flag Task' and 'Digit Span Task'. The major findings were as follows. First, the 5-year-olds motor proficiency was found to be better than the 4-year-olds. Second, the 5-year-olds executive function was found to be better than the 4-yeat-olds. Last, the 4-year-olds' and 5-year-olds' motor proficiency was related to their executive function. Concretely, fine manual control of motor proficiency was executive function and there was a high correlation. And behavior response inhibition and working memory of executive function was motor proficiency and there was a high correlation. Data analysis showed that preschoolers' motor proficiency and their executive function were different by their age level and that preschoolers' motor proficiency was correlated with their executive function.