• The Journal of Korean society of community based occupational therapy
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• v.9 no.2
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• pp.13-22
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• 2019

Objective : The purpose of this technical research is to determine decline of episodic memory by normal aging focucing on object, spatial location, and temporal order memory. Methods : We allocated seventy-seven of healthy adults from twenty to eighty years old, and performed computer-based cognitive tasks which were consisted of the object, spatial location, and temporal order memory. We used OpenSesame(OpenSesame Inc, OR), put ten pictures people normally see in their daily life, and evaluated those aspects through asking the objects types, object spatial locations, and picture temporal orders from 10 sheets of the picture. Results : Object and spatial location memory were not affected by normal aging whereas, temporal order memory significantly decreased with normal aging. Specifically, temporal order memory for in their age of forty was significantly decreased compared with their age of twenty and object memory at their age of eighty was relatively high compared to spatial location and temporal order memory. We found out that temporal order memory worse fastest and object memory lasted longest. Conclusion : In this study, we confirmed characteristics of declines of episodic memory consisting of object, spatial location, and temporal order memory. Notably, we could specifically identify declines of spatial location and temporal order memory with normal aging previous studies investigated on a limited basis using conventional neuropsychological assessments. These findings would be helpful to screen impairment in episodic memory by normal aging and provide an evidence that cognitive intervention for healthy older adults needs to include spatial and temporal aspect of memory.

• 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.

• Therapeutic Science for Rehabilitation
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• v.9 no.4
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• pp.95-106
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• 2020

Objective : The purpose of this study was to systematically review sex differences in episodic memory. Methods : We searched previous studies published in all electronic databases between 2010 and 2019. The key terms used in the search were 'sex differences' or 'gender differences' and 'episodic memory' or 'autobiographical memory'. 8 studies were finally extracted for analysis. Results : The 8 studies had evidence levels of II (67.5%) and III (37.5%), which are quite high. Healthy younger adults or healthy adults were recruited to examine sex differences in episodic memory. Assessment methods for episodic memory were mainly divided into cognitive tasks or standardized tests using visual or auditory stimuli. Subjects were instructed to memorize the stimuli and asked to recall them after some time. Overall females outperformed male. In particular, there were significant sex differences in verbal episodic memory. In contrast, there was no significant sex difference in visual episodic memory. Conclusion : To identify sex differences in episodic memory, a variety of test methods were used in various ways. Overall, females showed higher episodic memory than males. These findings suggest a need for cognitive intervention considering sex differences in the clinic. In the future, episodic memory tests with high ecological validity should be conducted to investigate sex differences in episodic memory.

• Therapeutic Science for Rehabilitation
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• v.10 no.1
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• pp.105-114
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• 2021

Objective : The purpose of this study was to identify and compare the sex differences in episodic memory and spatial cognition in healthy young adults. Methods : Forty-eight undergraduates (male=24, female=24) were assessed for sex differences using the visual stimuli episodic memory task and the virtual reality-based spatial cognition task. The accuracy rates (%) for the What, Where, and When conditions of the episodic memory task and the average distance error (cm) for 10 trials of the spatial cognition task were analyzed. Results : There were no significant sex differences between the three conditions. The male participants showed a significantly higher performance on the spatial cognition task than the female participants Conclusion : The results of this study indicated that the sex differences in episodic memory could be altered by the test methods. Although episodic memory and spatial cognition mainly depend on the hippocampus, the sex-related differences between the two functions were inconsistent, suggesting that these two functions are independent.

• Korean Journal of Cognitive Science
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• v.20 no.1
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• pp.79-107
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• 2009

Episodic memory, i.e. memorization of information within a spatiotemporal environment, is affected Alzheimer's disease(AD), but its impairment may also be occurred in the normal aging process. The purpose of this study is to analyze and evaluate memory in with Dementia of Alzheimer Type by examining their cognitive skills in episodic memory using the technique. This new method involves assessing the mental images the subject's own past in the mind like projected and movies. Three patients in the early stage of Dementia of Alzheimer Type, one with mild depression, and 2 healthy controls for comparison were asked to retrieve their episodic memory of the previous day, week, month, and a day testing day. The answers were then analyzed with regards to their specific features as emotional state, color, and time order. In the following day, the subjects were tasked to recall again the images they reproduced in the day's test order to observe of memory. Results showed that all 3 patients failed to arrange the retrieved images in time order and their images of the previous day were unclear in color and were stationary like photographs, even when they reproduced the mental images at much quantity as controls. patients could not remember particular events of yesterday, and only recalled the general occurrences of every day life. These results suggest that in the early stage of Dementia of Alzheimer Type, difficulties in the retrieval of recent episodic memory begin to primarily occur, and qualitative impairment happens earlier than quantitative.

• 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.

• Journal of KIISE
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• v.44 no.1
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• pp.51-56
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• 2017

The research area for solving question answering (QA) problems using artificial intelligence models is in a methodological transition period, and one such architecture, the dynamic memory network (DMN), is drawing attention for two key attributes: its attention mechanism defined by neural network operations and its modular architecture imitating cognition processes during QA of human. In this paper, we increased accuracy of the inferred answers, by adapting an automatic data augmentation method for lacking amount of training data, and by improving the ability of time perception. The experimental results showed that in the 1K-bAbI tasks, the modified DMN achieves 89.21% accuracy and passes twelve tasks which is 13.58% higher with passing four more tasks, as compared with one implementation of DMN. Additionally, DMN's word embedding vectors form strong clusters after training. Moreover, the number of episodic passes and that of supporting facts shows direct correlation, which affects the performance significantly.