• 한국문헌정보학회지
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• 제48권2호
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• pp.379-398
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• 2014

This pilot study explored the effect of mental demand on a Web searcher's thoughts, emotions, efforts, and performance in Web searches in order to address whether or not there is any difference between searchers exposed to mental demand manipulation and searchers not exposed. Research data were collected via think-aloud protocol (TAP) with a dual-task in experiments and interviews with 10 subjects who participated in this study. For the searcher's thoughts, relevance judgment was found to be hindered by mental demand. For the searcher's emotions, the experimental group was more frustrated than the control group. With respect to the searcher's efforts, searchers for the experimental group with mental demand manipulation were more likely to spend more time, make fewer queries, and visit fewer pages but work harder to find more relevant information that they needed. Lastly, with regard to the searcher's performance, it is likely that performance was highly dependent upon the completion of the search tasks for both groups. The NASA-TLX six components and cognitive load scores of searchers did not make a significant difference in the outcome. The findings support the use of a dual-task methodology as a promising approach for the assessment of cognitive load induced by complex Web searches.

• Physical Therapy Rehabilitation Science
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• 제13권2호
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• pp.213-222
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• 2024

Objective: Stroke is a leading cause of disability worldwide, often leaving survivors with significant cognitive and motor impairments. Dual-task (DT), which involves performing cognitive and motor tasks simultaneously, can influence brain activation patterns and functional recovery in stroke patients. Design: A systematic review Methods: Following PRISMA guidelines, databases including MEDLINE, CINAHL, Embase, and Web of Science were searched for studies assessing cortical activation via functional near-infrared spectroscopy (fNIRS) during DT performance in stroke patients. Studies were selected based on predefined eligibility criteria, focusing on changes in hemodynamic responses and their correlation with task performance. Results: Eight studies met the inclusion criteria. Findings indicate that DT leads to increased activation in the prefrontal cortex (PFC), premotor cortex (PMC), and posterior parietal cortex (PPC), suggesting an integrated cortical response to managing concurrent cognitive and motor demands. However, increased activation did not consistently translate to improved functional outcomes, highlighting the complex relationship between brain activation and rehabilitation success. Conclusions: DT interventions may enhance cortical activation and neuroplasticity in post-stroke patients, but the relationship between increased brain activity and functional recovery remains complex and requires further investigation. Tailored DT programs that consider individual neurophysiological and functional capacities are recommended to optimize rehabilitation outcomes.

• 재활치료과학
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• 제5권1호
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• pp.23-32
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• 2016

목적 : 본 연구는 이중과제 훈련을 뇌졸중 환자에게 적용하여 미치는 효과를 살펴본 국외 연구에 대해서 분석하는 것이다. 연구방법 : 2007년부터 2015년까지 국외 학회지에 게재된 논문을 Pubmed를 통하여 검색을 실시했다. 분류 및 선정과 배제조건을 통해 총 5개의 실험연구 논문을 포함논문으로 선정하였다. 결과 : 선정된 5편의 문헌은 모두 사전사후 대조군 설계로, PEDro score은 6점 이상으로 높은 편에 속했다. 사용된 중재에서 채택된 운동과제는 모두 보행과제였으며, 인지과제는 다양한 과제를 포함하여 범위가 넓었다. 사용된 평가도구는 표준화된 평가도구부터 조작적 정의에 의한 평가가 사용되었고, 더 나아가 이중과제 훈련을 위하여 고안된 평가도구도 포함되어 다양한 측면을 평가하는 것이 가능하였다. 고찰 : 본 연구를 통하여 이중과제 훈련이 뇌졸중 환자의 운동 및 인지기능의 향상 뿐 만 아니라 이중과제 수행에 긍정적인 영향을 주는 것을 확인할 수 있었지만, 이와 같은 결과를 통하여 현재까지 진행된 뇌졸중 환자 대상의 이중과제 훈련의 제한점 또한 알 수 있었다. 이러한 결과는 작업치료 분야에 적용을 위하여 보완점을 제시하는 기초자료로서의 역할과 효과적 치료를 알리는 데 도움이 될 것으로 사료된다.

• Safety and Health at Work
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• 제10권3호
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• pp.321-326
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• 2019

Background: Performing cognitive tasks and muscular fatigue have been shown to increase muscle activity of the lower extremity during quiet standing. A common intervention to reduce muscular fatigue is to provide a softer shoe-surface interface. However, little is known regarding how muscle activity is affected by softer shoe-surface interfaces during static standing. The purpose of this study was to assess lower extremity muscular activity during erect standing on three different standing surfaces, before and after an acute workload and during cognitive tasks. Methods: Surface electromyography was collected on ankle dorsiflexors and plantarflexors, and knee flexors and extensors of fifteen male participants. Dependent electromyography variables of mean, peak, root mean square, and cocontraction index were calculated and analyzed with a $2{\times}2{\times}3$ within-subject repeated measures analysis of variance. Results: Pre-workload muscle activity did not differ between surfaces and cognitive task conditions. However, greater muscle activity during post-workload balance assessment was found, specifically during the cognitive task. Cognitive task errors did not differ between surface and workload. Conclusions: The cognitive task after workload increased lower extremity muscular activity compared to quite standing, irrespective of the surface condition, suggesting an increased demand was placed on the postural control system as the result of both fatigue and cognitive task.

• 대한통합의학회지
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• 제9권2호
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• pp.23-33
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• 2021

Purpose : This study aimed to investigate the effects of dual-task training according to the variability of the walking environment on balance, gait, and function in patients with stroke. Methods : Twenty-five patients with stroke were randomly assigned to experimental group I (n=12) and experimental group II (n=13). Experimental group I and II performed obstacle and non-obstacle walking training, respectively, along with cognitive tasks for 21 minutes per session, 3 times a week for 6 weeks. Both groups received additional general physical therapy for 30 minutes per session. The functional reach test (FRT), gait analyzer (G-Walk), and functional independence measure (FIM) were used to evaluate balance, gait and function of pre- and post-interventions, respectively, while gait cadence, gait velocity, and stride length were evaluated using a gait analyzer. Results : In the within-group comparison of FRT, all the two groups showed significant post-intervention improvements (p<.05). In within-group comparison of gait cadence, all the two groups showed significant post-intervention improvements (p<.05). In within-group comparison of gait velocity, all the two groups showed significant post-intervention improvements (p<.05). In within-group comparison of stride length, experimental group I showed significant post-intervention improvements (p<.05), while experimental group II did not show significant post-intervention improvements (p>.05). In within-group comparison of FIM scores, experimental group I showed significant post-intervention improvements (p<.05), while experimental group II did not show significant post-intervention improvements (p>.05). There was a significant difference in the change of FIM scores pre- and post-intervention (p<.05) in the between-group comparison. Conclusion : The results of this study show that dual-task training with cognitive tasks and walking training can improve the balance, gait and function of patients with stroke, and obstacle walking training is effective for improving functions including activities of daily living compared to non-obstacle walking training.

• The Journal of Korean Physical Therapy
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• 제35권3호
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• pp.64-70
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• 2023

Purpose: This study investigated the influence of attention-demanding tasks on gait and measured differences in the temporal, spatial and kinematic characteristics between young healthy adults and elderly healthy adults. Methods: We recruited 16 healthy young adults and 15 healthy elderly adults in this study. All participants performed two cognitive tasks: a subtraction dual-task (SDT) and working memory dual-task (WMDT) during gait plus one normal gait. Using the LEGSys+ system, knee and hip-joint kinematic data during stance and swing phase and spatiotemporal parameter data were assessed in this study. Results: In the elderly adult group, attention-demanding tasks with gait showed a significant decrease in hip-joint motion during the stance phase, compared to the normal gait. Step length, stride length and stride velocity of the elderly adult group were significantly decreased in WMDT gait compared to normal gait (p<0.05). In the young adult group, kinematic data did not show any significant difference. However, stride velocity and cadence during SDT and WMDT gaits were significantly decreased compared to those of normal gait (p<0.05). Conclusion: We determined that attention-demanding tasks during gait in elderly adults can induce decreased hip-joint motion during stance phase and decreased gait speed and stride length to maintain balance and prevent risk of falling. We believe that understanding the changes during gait in older ages, particularly during attention-demanding tasks, would be helpful for intervention strategies and improved risk assessment.

• 대한치매학회지
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• 제22권4호
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• pp.139-147
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• 2023

Background and Purpose: Dual walking task such as crossing over an obstacle may serve as an excellent tool for predicting early cognitive decline. Thus, this study aimed to investigate correlation between walking while crossing over an obstacle and executive functions under different gait phases to validate the use of walking with an obstacle for predicting early cognitive decline. Methods: A cross-sectional study was conducted on 48 elderly individuals from 2 day-care centers and 3 welfare-centers in Seoul and Gyeonggi, Korea. Executive function tests (Trail Making Test, Stroop test) and dual walking tests (gait speed, cadence, stance time, gait cycle time) were performed and compared using partial correlation analysis. Results: There were significant correlations between executive function and most of the gait variables (stance time, cadence, and gait cycle time) (p<0.05) when crossing over an obstacle while walking. Especially, stance time exhibited significant correlations with most executive functions (p<0.05). Conclusions: When evaluating executive function during walking with an obstacle, post-obstacle-crossing phase and stance time need to be observed.

• Physical Therapy Rehabilitation Science
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• 제4권1호
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• pp.44-48
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• 2015

Objective: The purpose of this study was to investigate the relationship between anticipatory postural adjustment (APA), single task, dual tasks and physical performances. The trunk muscles of APA consist of bilateral erector spinae (ES) and bilateral internal oblique (IO) adnominal muscles, during rapid stepping with the affected or unaffected leg in a sitting posture. Design: Cross-sectional study. Methods: In patients with chronic stroke, electrodes of surface electromyography (EMG) were attached on the bilateral erector spinae (ES), bilateral internal oblique adnominal (IO), and bilateral rectus femoris (RF) muscles. RF acts as the prime mover. The stroke patients performed hip flexion until $20^{\circ}$ as fast as possible at each leg in a sitting posture according to a visual cue. The visual cue unexpectedly appeared on monitor in front of the stroke patient. The single task was the Timed Up and Go (TUG) test. The dual tasks were the TUGconitive, which increased cognitive capacity, and the TUGmanual task, which had an external focus. Results: All EMG data showed earlier onset latency before the prime mover. In affected leg raising, the onset time of unaffected ES muscle of the stroke patients was correlated with the single and dual tasks (p<0.05). In unaffected leg raising, the onset time of the affected IO muscle was related to all the tasks (p<0.05). Gait speed showed a relationship with the unaffected ES muscle only. Conclusions: The trunk muscles of the bilateral ES and bilateral IO play an important role in APA. The single and dual tasks using TUG test were correlated with the APA s of ES and IO muscles. Dual task by the TUG test is a good measuring tool for reflecting the real life in patients with chronic stroke.

• PNF and Movement
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• 제21권1호
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• pp.11-18
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• 2023

Purpose: This study aims to compare the effects of obstacle walking training combined with cognitive tasks on balance, gait, and activities of daily living in patients with stroke. Methods: A single-subject design was used, where one stroke patient participated. Obstacle walking training combined with cognitive tasks was performed for 1 hour per day for a total of 10 times during the intervention phase. The subjects were measured five times in the baseline phase, 10 times in the intervention phase, and five times in the follow-up phase. The outcome measurements included the Berg balance scale (BBS), the 10-meter walk test (10 MWT), and the Korean modified Barthel index (K-MBI). Results: In this study, the results showed that the 10 MWT scores during the intervention period improved and that this improvement remained, even during the post-period. In addition, BBS and K-MBI values for stroke patients increased significantly after training. Conclusion: The results of this study revealed that obstacle walking training combined with cognitive task training may be helpful to improve balance, gait, and activities of daily living in stroke patients. Therefore, obstacle walking training combined with cognitive tasks is recommended for stroke patients.

• 인지과학
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• 제7권3호
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• pp.115-134
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• 1996

외현기억은 의도적 인출을 의미하고 암묵기억은 비의도적 인출을 의미하며 다양한 변인하에서 외현기억과 암묵기억이 상이한 인출형태가 보이는 것을 기억해리현상이라 한다.본 연구에서는 기억해리현상을 설명하는 처리이론중 이중처리이론의 기본 가정을 수용하여 실험을 실시하였다.처리깊이에 따른 학습을 실시하면,지각 처리과제의 경우는 단어표상의 활성화가 이루어지며 이는 접속가능성의 증가로 나타나고,의미처리과제의 경우는 목표단어표상 및 관련단어의 표상이 활성화되고 이는 인출가능성의 증가로 나타난다.학습단계에서는 의미처리과제와 지각처리과제를 반복해서 제시하여 접속가능성과 인출가능성의 증가를 조작하였고,검사단계에서는 인출 지시문 종류에 따른 암묵 기억검사와 외현기억검사를 실시하였다.실험결과는 다음과같다. 지각처리과제의 반복은 암묵기억검사와 파지수준에는 영향을 주지만 외현기억검사의 파지수준에는 효과를 미치지 못했고,의미처리 과제의 반복은 암묵기억검사와 외현기억검사 파지 수준 모두에 영향을 미쳤다.실험결과를 종합하여 보면,처리깊이에 다른 학습 단어 반복제시의 기억 해리효과는 이중처리이론의 설명틀이 적절하다고 결론지울수 있다.