• Physical Therapy Rehabilitation Science
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• v.13 no.2
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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.

• Proceedings of the KSPS conference
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• 2003.05a
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• pp.93-96
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• 2003

The present study was conducted to investigate the difference of cortical activation in naming the picture in Korean and English. Experimental design was 2(Korean, English) language condition x 4(no distractor, semantic related distractor, semantic unrelated distrator, corresponding distractor) distractor condition. language condition was between subject factor and distractor condition was within subject factor. The result was that Korean naming condition showed less cortical activation than English naming condition. The activation region was reported in each condition.

• The Journal of Korean Physical Therapy
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• v.21 no.1
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• pp.81-87
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• 2009

Purpose: Human brain was lateralized to dominant or non-dominant hemisphere, and could be reorganized by the processing of the motor learning. We reported four cases which showed the changes of the cortical activation patterns resulting from two weeks of training with the serial reaction time task. Methods: Four right-handed healthy subjects were recruited, who was equally divided to two training conditions (right hand training or left hand training). They were assigned to train the serial reaction time task for two weeks, which should press the corresponding four colored buttons as fast as accurately as possible when visual stimulus was presented. Before and after two weeks of training, reaction time and function magnetic resonance image (fMRI) was acquired during the performance of the same serial reaction time task as the training. Results: The reaction time was significantly decreased in all of subjects after training. Our fMRI result showed that widespread bilateral activation at the pre scanning was shifted toward the focused activation on the contralateral hemisphere with progressive motor learning. However, the bilateral activation was still remained during the performance of the non-dominant hand. Conclusion: These findings showed that the repetitive practice of the serial reaction time task led to increase the movement speed and accuracy, as described by motor learning. Such motor learning induced to change the cortical activation pattern. And, the changed pattern of the cortical activation resulting from motor learning was different each other in accordance with the hand dominance.

• The Journal of Korean Physical Therapy
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• v.21 no.4
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• pp.73-79
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• 2009

Purpose: Recently, neurostimulation studies involving manipulation of cortical excitability of the human brain have been increasingly attempted. We investigated whether transcranial direct current stimulation (tDCS) applied to the underlying cerebral cortex, directly induces cortical activation during fMRI scanning. Methods: We recently recruited five healthy subjects without a neurological or psychiatric history and who were right-handed, as verified by the modified Edinburg Handedness Inventory. fMRI was done while constant anodal tDCS was delivered to the underlying SM1 area?? immediately after the pre-stimulation for eighteen minutes. Results: Group analysis yielded an averaged map that showed that the SM1 area and the superior parietal cortex in the ipsilateral hemisphere were activated. The voxel size and peak intensity were, respectively, 82 and 5.22 in the SM1, and 85 and 5.77 in the superior parietal cortex. Conclusion: Cortical activation can be induced by constant anodal tDCS of the underlying motor cortex. This suggests that tDCS may be an effective therapeutic device for enhancing? physical motor function by modulating neural excitability of the motor cortex.

• Journal of the Korean Society of Physical Medicine
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• v.5 no.3
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• pp.467-476
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• 2010

Purpose : This study was performed to understand the relationship between hand and mouth shapes using functional magnetic resonance imaging(fMRI). Methods : Two healthy volunteers without any previous history of physical or neurological illness were recruited. fMRI was done that volunteers was 6 repeated of natural mouth, close mouth and open mouth while power grip and pinch grip movement. Results : Cerebral cortex activation was not well observed for the natural mouth during the power grip exercise. For the closed mouth, the temporal lobe, Broca's area, the prefrontal area related to thinking and judgment, the supplementary motor area, the auditory area and Wernicke's area were activated. For the open mouth, cortical activation was also observed in the temporal lobe, Wernicke's area, the prefrontal area related to thinking and the orbital frontal area related to visual sense. During the pinch grip exercise, cortical activation was observed for the natural mouth in the primary sensory area, Wernicke's area, the primary and supplementary motor area, and the prefrontal area. For the closed mouth, cortical activation was observed in the temporal lobe, Wernicke's area, the prefrontal area related to thinking, the secondary visual area, the primary sensory area and the supplementary motor area. In the case of the open mouth, cortical activation was observed in a few parts in the temporal lobe as well as Wernicke's area, the prefrontal area related to thinking, and other areas related to visual sense such as the primary visual area, the secondary visual area and the visual association area. Conclusion : Brain was more activation for close mouth and open mouth more than natural mouth movement.

• International Journal of Oral Biology
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• v.34 no.4
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• pp.199-203
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• 2009

This study investigated whether orthodontic force influences the production of osteoprotegerin (OPG) and receptor activator of nuclear factor-kappa B ligand (RANKL) in vivo, both of which are affected by cortical activation. Mechanical force was applied to the maxillary premolars of orthodontic patients by fitting the transpalatal arch prior to cortical activation of the gingival tissue. Gingival crevicular fluid (GCF) samples were then collected from each patient using paper strips before and after 1, 3, 7 or 14 days of treatment. The OPG and RANKL levels in the GCF were determined by enzyme-linked immunosorbent assays. The levels of OPG were significantly increased after 1 day of fitting the appliance and decreased to basal levels at 3 days after fitting. In contrast, the RANKL levels were dramatically decreased at 1 day after fitting, but recovered to those of the untreated control at 3 days after the force application. The force-mediated changes in the OPG and RANKL levels of the GCF were unaffected by cortical activation during these experimental periods. Collectively, these results suggest that an acute and severe change between the OPG and RANKL levels plays an important role in stimulating the cellular responses required for alveolar bone remodeling by orthodontic treatment.

• The Journal of Korean Physical Therapy
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• v.23 no.6
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• pp.49-53
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• 2011

Purpose: The purpose of this study is to investigate whether dual-hemisphere transcranial direct current stimulation (tDCS) could induce more cortical activity, compared to single-hemisphere, using functional MRI (fMRI). Methods: One right-handed healthy subject was recruited. Three phases of dual-hemisphere tDCS (i.e. anodal tDCS over the left-dominant primary sensoriomotor cortex (SM1) and cathodal tDCS over the right-non dominant SM(1) were consecutively delivered on to a subject, during fMRI scanning. The voxel count and the intensity index in the averaged cortical map were analyzed among the three tDCS phases. Results: Our result showed that cortical activation was observed on all the three phases of the dual-hemisphere tDCS. Voxel count and intensity index were as following; 912 and 4.07 in the first phase, 1102 and 3.90 in the second phase, 1031 and 3.80 in the third phase. Conclusion: This study demonstrated that application of the dual-hemisphere tDCS could induce cortical activity and maintain to recruit cortical neurons. Our findings suggested that application of dual-hemisphere tDCS could produce efficiency of the ongoing tDCS effect to facilitate cortical excitability.

• Proceedings of the KSMRM Conference
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• 2001.11a
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• pp.105-105
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• 2001

Purpose： The activation of the Brocas and the Wernickes area in the language functional MR (fMR) well-known phenomena. We want to evaluate correlation of that activation with langua lateralization. So we evaluate the lateralization using the activation of the Brocas and t Wernickes area comparing with total cortical activation amount of cerebral hemisphere in t functional MR for measuring language lateralization based on Wada test.

• The Journal of Korean Physical Therapy
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• v.23 no.1
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• pp.77-82
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• 2011

Purpose: Recently, many studies have demonstrated that application of external stimulation can modulate cortical excitability of the human brain. We attempted to observe cortical excitability using functional magnetic resonance imaging (fMRI) during the application of transcranial direct current stimulation (tDCS) or functional electrical stimulation (FES). Methods: We recruited two healthy subjects without a history of neurological or psychiatric problems. fMRI scanning was done during? each constant anodal tDCS and FES session, and each session was repeated three times. The tDCS session consisted of three successive phases (resting phase: 60sec dummy cycle: 10sec tDCS phase: 60sec). The FES session involved stimulation of wrist extensor muscles over two successive phase (resting phase: 15sec FES phase: 15sec). Results: The average map of the tDCS and FES analyses showed that the primary sensory-motor cortex area was activated in all subjects. Conclusion: Our findings show that cortical activation can be induced by constant anodal tDCS and FES. They suggest that the above stimuli have the potential for facilitating brain plasticity and modulating neural excitability if applied as specific therapeutic interventions for brain injured patients.

• Journal of Biomedical Engineering Research
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• v.28 no.1
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• pp.139-147
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• 2007

The aim of this study was to evaluate effects of short-tenn repetitive-bilateral excercise on the activation of motor network using functional magnetic resonance imaging (fMRI). The training program was performed at 1 hr/day, 5 days/week during 6 weeks. Fugl-Meyer Assessments (FMA) were performed every two weeks during the training. We compared cerebral and cerebellar cortical activations in two different tasks before and after the training program: (1) the only unaffected hand movement (Task 1); and (2) passive movements of affected hand by the active movement of unaffected hand (Task 2). fMRI was performed at 3T with wrist flexion-extension movement at 1 Hz during the motor tasks. All patients showed significant improvements of FMA scores in their paretic limbs after training. fMRI studies in Task 1 showed that cortical activations decreased in ipsilateral sensorimotor cortex but increased in contralateral sensorimotor cortex and ipsilateral cerebellum. Task 2 showed cortical reorganizations in bilateral sensorimotor cortex, premotor area, supplemetary motor area and cerebellum. Therefore, this study demonstrated that plastic changes of motor network occurred as a neural basis of the improvement subsequent to repetitive-bilateral excercise using the symmetrical upper-limb ann motion trainer.