• Korean Journal of Cognitive Science
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• v.21 no.2
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• pp.359-386
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• 2010

In order to evaluate the domain-specific model and process-specific model of spatial and nonspatial working memory (WM), this study manipulated the memory load of the delayed response task and examined how the neural correlates of memory load effect was influenced by the stimulus domain (face and location) at the maintenance stage of WM using an event-related fMRI experiment. One or three face stimuli were presented as target stimuli and participants were asked to maintain the face itself (face WM) or the location of face stimuli (spatial WM). The results of recognition judgment accuracy showed no difference between face WM and spatial WM, and showed equivalent memory load effects of both WM. As a result of brian image analysis, memory load effect at maintenance stage showed that inferior, middle, and superior PFC were recruited by both face WM and spatial WM, and showed that VLPFC was the commonly activated area by both WM, supporting functional specialization of PFC by process components of WM. This study provides evidence for process-specific model in which maintenance of WM is associated with VLPFC.

• Proceedings of the Korean Society for Cognitive Science Conference
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• 2005.05a
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• pp.216-219
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• 2005

언어 작업기억과 시공간 작업기억이 아동의 글 이해에 미치는 영향을 알아보기 위해 정상 아동과 읽기 지진아동들에게 두 개의 연구를 실시하였다. 연구 1에서는 글의 유형(설명글과 묘사글)별로 글 이해 정도와 언어작업기억과 시공간 잡기장 용량을 측정하여, 정상아동과 읽기 지진 아동 간에 차이가 있는지 알아보았다. 연구 2에서는 글 유형과 2차 기억과제와의 간섭효과를 측정하여 보다 직접적으로 글 유형에 따라 관여하는 작업기억의 종류가 다를 수 있는지를 알아보았다. 두 연구에서 읽기지진 아동은 묘사글을 읽을 때 시공간 작업기억을 사용하는 것을 밝혀내었다.

• Korean Journal of Cognitive Science
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• v.16 no.3
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• pp.155-174
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• 2005

Oh and Kim (2004) and Woodman and Lurk (2004) demonstrated that spatial working memory (SWM) load Interfered concurrent visual search and that search process also impaired the maintenance of spatial information implying that visual search and SWM task both require access to the same limited-capacity mechanism. Two obvious possibilities have been suggested about what this shared limited-capacity mechanism is: common demand for attention to the locations where the items f9r the two tasks were presented (spatial attention load hypothesis), and common use of working memory to maintain a record of locations have been processed(SWM load hypothesis). To test these two hypothetical explanations, Experiment 1 replicated the mutual interference between visual search and SWM task in spite of difference of procedure with preceding researches; possible areas where the items for two tasks were presented were not separated. In Experiment 2, we presented the items for visual search either in the same quadrants where the items for SWM task had appeared (same-location rendition) or in the different quadrants (different-location condition). As a result, search efficiency was more impaired in the different-location condition than in the same-location condition. The memory accuracy was worse in the different-location rendition than in the same-location rendition. Overall results of study indicate that the mutual interference between SWM and visual search might be related to the overload of spatial attention, but not to that of SWM.

• Korean Journal of Cognitive Science
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• v.19 no.2
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• pp.125-142
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• 2008

This study investigated the effects of space- and object-based attention on spatial and visual working memory, by measuring recognition of working memory on the spatial Stroop task including two modalities of attention resource. The similarity condition of stimulus arrangement between working memory task and spatial stroop task was manipulated in order to examine the effects of space-based attention on spatial rehearsal during working memory task, while Stroop rendition was manipulated in order to examine the effects of object-based attention on object rehearsal during working memory task. The results showed that in a condition that stimulus arrangement was highly similar for the spatial working memory task and the spatial Stroop task, recognition accuracy of the spatial working memory was high, but it was not significantly different with the Stroop conditions. In contrast, the recognition accuracy of visual working memory in the incongruent Stroop condition was lower than that in the congruent Stroop condition, but it was not significantly different with the similarity conditions (25% vs. 75%). The results indicated that selective attention has effects on working memory only when resource modality of working memory is the same as that of selective attention.

• The Korean Journal of Nuclear Medicine
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• v.32 no.3
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• pp.238-249
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• 1998

Purpose: To localize and compare the neural basis of verbal and visual human working memory, we performed functional activation study using $H_2^{15}O$ PET. Materials and Methods: Repeated $H_2^{15}O$ PET scans with one control and three different activation tasks were performed on six right-handed normal volunteers. Each activation task was composed of 13 match-ing trials. On each trial, four targets, a fixation dot and a probe were presented sequentially and subject's task was to press a response button to indicate whether or not the probe was one of the previous targets. Short meaningful Korean words, simple drawings and monochromic pictures of human faces were used as matching objects for verbal or visual memory. All the images were spatially normalized and the differences between control and activation states were statistically analyzed using SPM96. Results: Statistical analysis of verbal memory activation with short words showed activation in the left Broca's area, promoter cortex, cerebellum and right cingulate gyrus. In verbal memory with simple drawings, activation was shown in the larger regions including where activated with short words and left superior temporal cortex, basal ganglia, thalamus, prefrontal cortex, anterior portion of right superior temporal gyrus and right infero-lateral frontal cortex. On the other hand, the visual memory task activated predominantly right-sided structures, especially inferior frontal cortex, supplementary motor cortex and superior parietal cortex. Conclusion: The results are consistent with the hypothesis of the laterality and dissociation of the verbal and visual working memory from the invasive electrophysiological studies and emphasize the pivotal role of frontal cortex and cingulate gyrus in working memory system.

• Korean Journal of Cognitive Science
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• v.10 no.4
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• pp.41-50
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• 1999

It is widely known that the hippocampus plays an important role in spatial memory. Recent studies have suggested that the posterior parietal cortex (PPC) is involved in spatial memory. However it is unclear whether the PPC is involved in w working memory or reference memory of spatial learning. The purpose of the present study was to determine contribution of the hippocampus and the PPC to spatial working memory and acquisition of reference memory. Using an eight-arm radial maze in which e each arm was baited. working memory was tested by measuring rat's ability to remember arms they had visited. Reference memory was tested by measuring rat's ability to avoid visiting four consistently unbaited arms. Effects of hippocampal or PPC lesion on working memory or acquisition of reference memory in radial-arm maze learning were investigated Working memory was impaired by hippocampal lesion whereas not affected by PPC lesion. Acquisition of reference memory was impaired by lesion in either site. The results suggest that the hippocampus plays an important role in the spatial working memory while both the hippocampus and the PPC contribute to the acquisition of spatial reference memory.

• The Journal of the Korea Contents Association
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• v.15 no.4
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• pp.545-555
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• 2015

We investigated the influence of negative emotion such as state-trait anxiety and depression and working memory (WM) on Foreign Language Vocabulary Learning (FLVL) of South Korean university students. Also, its implications for developing contents for FLVL were discerned. To do so, state-trait anxiety and depression inventories as well as four kinds of WM test were performed for 132 undergraduate students. Participants also had two semantic learning sessions for Swahili words. The mean scores of negative emotions were normal level. The results of structural equation modeling (SEM) showed that there was no effect of negative emotion on FLVL, while direct effects of the negative emotion on WM and the WM on FLVL were significant. Such results suggested that FLVL would be weakened, with the result that WM had been impaired by negative emotions. These outcomes suggested that when developing FLVL content for university students, it is necessary to consider the negative emotions of foreign language learners and to develop the contents for FLVL in the light of WM load.

• Korean Journal of Cognitive Science
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• v.17 no.3
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• pp.191-206
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• 2006

Two experiments were conducted to investigate the effects of verbal working memory and the spatial working memory on children's text comprehension. The reading span and the operation span of the reading deficient children were smaller than that of the reading normal children, but the two groups did not differ in the visual span. Reading deficient children got lower score in the comprehension tests than reading normal children, and the difference was larger for the expository text than the narrative text. The involvement of visual working memory in reading narrative texts were more directly tested in Experiment 2 by asking the children do a secondary memory task before they answered the comprehension test. Reading normal children suffered more under auditory secondary memory condition for both narrative and expository texts, whereas reading deficient children suffered under visual secondary memory condition for narrative texts as well. The results of the two experiments suggested that the spatial working memory can be involved in text comprehension process, especially with reading deficient children.

• Korean Journal of Cognitive Science
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• v.22 no.2
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• pp.193-215
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• 2011

The purpose of this study was to examine the working memory that is related with reading. For this purpose, the third and fourth grade children with reading difficulty were compared with normal children. The gender comparison and the correlations among the three components of working memory were also examined. The results indicated that the reading difficulty group were outperformed by the normal group in every test. Gender difference was found only in visuospatial capacity. There was an interaction between reading and gender in the memory of dynamic mazes. In the whole group, every correlation among all components was significant. When the correlations were examined separately in each group, however, only one correlation was significant in both groups. When the influence of the central executive was controlled, the interrelationship between phonological working memory and visuospatial working memory was mitigated. This study suggests that when teaching children with reading difficulty instructional material should be succinct and visuospatial information needs to be used for boys if possible.

• Journal of the Korea Convergence Society
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• v.11 no.12
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• pp.383-390
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• 2020

The present study was conducted to examine the differences and correlations between verbal fluency and story comprehension according to the working memory(WM) capacity, and to find out what WM factors influence the linguistic competence in Alzheimer's disease(AD) and vascular dementia(VaD) groups each consisting of 15 patients. The results of their performance produced firstly significant differences in phonemic fluency, story comprehension, delayed recall and recognition task between the two groups. Further analysis shows that VaD group had significant correlations between the scores of story comprehension and the recognition test scores additionally. These findings suggest that it is possible to differentiate the two groups even by story comprehension tasks and WM. In conclusion, the clinical application of the results is likely to contribute to appropriate treatment plans and effective interventions for elderly with AD and VaD as well as to improve the classification criteria for both types of dementia.