• Journal of the Korean Society of Physical Medicine
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• v.5 no.3
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• pp.395-404
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• 2010

Purpose : The object of this study was to examine the effect of motor learning on brain activation depending on the method of motor learning. Methods : The brain activation was measured in 9 men by fMRI. The subjects were divided into the following groups depending on the method of motor learning: actually practice (AP, n=3) group, action observation (AO, n=3) group and motor imagery (MI, n=3) group. In order to examine the effect of motor learning depending on the method of motor learning, the brain activation data were measured during learning. For the investigation of brain activation, fMRI was conducted. Results : The results of brain activation measured before and during learning were as follows; (1) During learning, the AP group showed the activation in the following areas: primary motor area located in precentral gyrus, somatosensory area located in postcentral gyrus, supplemental motor area and prefrontal association area located in precentral gyrus, middle frontal gyrus and superior frontal gyrus, speech area located in superior temporal gyrus and middle temporal gyrus, Broca's area located in inferior parietal lobe and somatosensory association area of precuneus; (2) During learning, the AD groups showed the activation in the following areas: primary motor area located in precentral gyrus, prefrontal association area located in middle frontal gyrus and superior frontal gyrus, speech area and supplemental motor area located in superior temporal gyrus and middle temporal gyrus, Broca's area located in inferior parietal lobe, somatosensory area and primary motor area located in precentral gyrus of right cerebrum and left cerebrum, and somatosensory association area located in precuneus; and (3) During learning, the MI group showed activation in the following areas: speech area located in superior temporal gyrus, supplemental area, and somatosensory association area located in precuneus. Conclusion : Given the results above, in this study, the action observation was suggested as an alternative to motor learning through actual practice in serial reaction time task of motor learning. It showed the similar results to the actual practice in brain activation which were obtained using activation of mirror neuron. This result suggests that the brain activation occurred by the activation of mirror neuron, which was observed during action observation. The mirror neurons are located in primary motor area, somatosensory area, premotor area, supplemental motor area and somatosensory association area. In sum, when we plan a training program through physiotherapy to increase the effect during reeducation of movement, the action observation as well as best resting is necessary in increasing the effect of motor learning with the patients who cannot be engaged in actual practice.

• Annals of Clinical Neurophysiology
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• v.7 no.1
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• pp.34-36
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• 2005

Two hemiplegic cerebral palsy patients were studied to investigate the cortical mechanisms underlying preserved somatosensory capacity, using functional MRI(fMRI). Tactile stimulation was performed by brushing of palm, during fMRI study. By the affected hand stimulation, contralateral primary somatosensory cortex was activated in patient 1 and cortical area anterior to the lesion site was activated in patient 2. We suggest that reorganization of the somatosensory cortex after brain injury can be induced by recruitment of undamaged areas adjacent to lesion site.

• The Journal of Korean Physical Therapy
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• v.22 no.4
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• pp.97-101
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• 2010

Purpose: Sensory input is very important for proper performance of human. Two-point discrimination is the most widely used tactile sensory test. The purpose of this study was to find the changes in cortical activation patterns between tactile stimulation and two-point discrimination. Methods: Two healthy subjects participated in our study. fMRI scanning was done during 4 repeated blocks of tactile stimulation and two point discrimination of the right index finger tip. In one block, stimuli were repeated 10 times every three seconds. To determine the changes of cortical neurons during sensory input, intensity index was analyzed. Results: When tactile stimulation of the right index finger tip was completed, only contralateral primary somatosensory area was activated. In contrast, during two-point discrimination, both the primary somatosensory area and ipsilateral supplementary sensory area were activated. Conclusion: During two point discrimination, both primary somatosensory area and ipsilateral supplementary sensory area were activated. Therefore, two-point discrimination is required more complex and conscious activity than tactile stimulation.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.19 no.2
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• pp.67-71
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• 2013

Background: The purpose of this study was to investigate the effects of somatosensory stimulations with joints mobilization in foot on balance and gait speed in elderly women. Methods: This study included 2 female participants aged 72 years. Participants received somatosensory simulations with joints mobilization on both foot for 30 minutes a day, 3 days a week, during a 4 week period. All subjects were assessed using a BT(balance trainer)-4 balance measurement and timed up and go test (TUG), 10m walk test (10MWT). Results: It has been found that static length and static area were reduced and limits of stability was increased in 2 females. TUG test was improved but gait speed was not significantly difference. Conclusion: Those results indicate that somatosensory stimulations with joints mobilization is effective in elderly women to promoting a static and dynamic balance ability.

• Physical Therapy Korea
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• v.27 no.2
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• pp.126-132
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• 2020

Background: Augmented somatosensory feedback stimulates the mechanoreceptor to deliver information on bodily position, improving the postural control. The various types of such feedback include ankle-foot orthoses (AFOs) and vibration. The optimal feedback to mitigate postural sway remains unclear, as does the effect of augmented somatosensory feedback on muscle co-contraction. Objects: We compared postural sway and ankle muscle co-contraction without feedback (control) and with either of two forms of somatosensory feedback (AFOs and vibration). Methods: We recruited 15 healthy subjects and tested them under three feedback conditions (control, AFOs, vibration) with two sensory conditions (eyes open, or eyes closed and the head tilted back), in random order. Postural sway was measured using a force platform; the mean sway area of the 95% confidence ellipse (AREA) and the mean velocity of the center-of-pressure displacement (VEL) were assessed. Co-contraction of the tibialis anterior and gastrocnemius muscles was measured using electromyography and converted into a co-contraction index (CI). Results: We found significant main effects of the three feedback states on postural sway (AREA, VEL) and the CI. The two sensory conditions exerted significant main effects on postural sway (AREA and VEL). AFOs reduced postural sway to a level significantly lower than that of the control (p = 0.014, p < 0.001) or that afforded by vibration (p = 0.024, p < 0.001). In terms of CI amelioration, the AFOs condition was significantly better than the control (p = 0.004). Vibration did not significantly improve either postural sway or the CI compared to the control condition. There was no significant interaction effect between the three feedback conditions and the two sensory conditions. Conclusion: Lower-extremity devices such as AFOs enhance somatosensory perception, improving postural control and decreasing the CI during static standing.

• Progress in Medical Physics
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• v.17 no.3
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• pp.159-166
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• 2006

The nonlinearity of hemodynamic response in the somatosensory cortex was investigated with vibrotactile stimulation. The stimuli consisted of a train of 25 Hz, each tasting five different duration periods, 2 s, 4 s, 8 s 12 s, or 16 s with 20 sec periods of no vibration in a pseudo-random order. In order to understand the linearity on the change of stimulus duration for somatosensory cortex, two different tests- checking the linearity of system and finding the impulse response function from gamma-variate function were applied to analyze the hemodynamic response functions. They have produced nearly same results. The BOLD response in the somatosensory cortex Is nonlinear for stimuli of less than 8 seconds, but nearly linear for stimuli greater than 8 seconds. The amplitude, area, TTP, and FWHM as functions of the stimulus duration were calculated and showed a significant downward trend with Increasing stimulus duration for the amplitude and the area. It supports the ranges of nonlinearity are less than 8 seconds.

• YAKHAK HOEJI
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• v.36 no.3
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• pp.269-277
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• 1992

The effects of ginseng saponins on the distribution of nerve cells in cerebral cortex of carbon monoxide (CO)-intoxicated mice were studied in the young ($5{\sim}8$ weeks) and aged ($43{\sim}52$ weeks) mice. Mice were exposed to 5000 ppm of CO for 40 minutes (72% HbCO). After that, nerve cells in motor(area 4), somatosensory(area 3) and visual(area 17) area of cerebral cortex was observed. In young mice, the number of nerve cells in each area was significantly decreased on 1st, 7th and 14th day after CO intoxication. In aged mice, that was also decreased after CO intoxication. Especially the number of the nerve cells in motor and somatosensory area was significantly decreased on 1st and 7th day, while that in visual area was decreased only on 1st day. The number of nerve cells in young mice pretreated with ginseng saponins were significantly decreased less on 7th and 14th day than that of untreated mice. The number of nerve cells in each area of normal aged mice was larger than that of normal young mice. The results suggest that CO exposure causes local degeneration or disturbance of nerve cells and delayed neurologic sequelae, while ginseng saponins might play a role of protective action on the nerve cells which were damaged by CO.

• Journal of the Ergonomics Society of Korea
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• v.33 no.5
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• pp.395-405
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• 2014

Objective: The aim of this study is to investigate 1) somatotopic arrangement of the second and third fingers in SI area 2) difference of neural activation in the SI area produced by stimulation with different frequencies 3) correlation between the intensity of tactile perception by different stimulus intensity and the level of brain activation measurable by means of fMRI. Background: Somatosensory cortex can obtain the information of environmental stimuli about "where" (e.g., on the left palm), "what" (e.g., a book or a dog), and "how" (e.g., scrub gently or scrub roughly) to organism. However, compared to visual sense, the neural mechanism underlying the processing of specific electrotactile stimulus is still unknown. Method: 10 right-handed subjects participated in this study. Non-painful electrotactile stimuli were delivered to two different finger tips of right hand. Functional brain images were collected from 3.0T MRI using the single-shot EPI method. The scanning parameters were as follows: TR and TE were 3000, 35ms, respectively, flip angle 60, FOV $24{\times}24cm$, matrix size $64{\times}64$, slice thickness 4mm (no gap). SPM5 was used to analyze the fMRI data. Results: Significant activations produced by the stimulation were found in the SI, SII, the subcentral gyrus, the precentral gyrus, and the insula. In all participants, statistically significant activation was observed in the contralateral SI area and the bilateral SII areas by the stimulation on the fingers but ipsilaterally dominant. The SI area representing the second finger generally located in the more lateral and inferior side than that of the third finger across all the subjects. But no difference in brain area was found for the stimulation of the fingers by different frequencies. And two typical patterns were observed on the relationship between the perceived psychological intensity and the amount of voxels in the primary sensory cortex during the stimulation. Conclusion: It was possible to discriminate the representation sites in the SI by electrotactile stimulation of digit2 and digit3. But we could not find the differences of the brain areas according to different stimulation frequencies from 3 to 300Hz. Application: The results of the study can provide a deeper understanding of somatosensory cortex and offer the information for tactile display for blinds.

• Journal of Acupuncture Research
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• v.20 no.4
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• pp.145-156
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• 2003

Objective : This study is to investigate the effect of electro-acupuncture ST36 on altered transmission of afferent somatosensory information caused by amyloid-${\beta}$(A-${\beta}$) that caused Alzheimer's disease. Methods : The effects of topical application of A-${\beta}$, A-${\beta}$ with ST36, aggregated A-${\beta}$(aA-${\beta}$), aA-${\beta}$ with ST36 and ST36 on the afferent sensory transmission to the neurons in the primary somatosensory(SI) cortex was observed in anesthetized rats. Quantitative determination of the effects of A-${\beta}$, A-${\beta}$ with ST36, aA-${\beta}$, aA-${\beta}$ with ST36 and ST36 was made by generating poststimulus time histogram of evoked response of individual cortical neuron by electrical stimulation of the receptive located in peripheral area(forepaw) Results : The results obtained in present study were summerized as follow : 1. Application of physiological concentrative 0.5 nM A-${\beta}$ caused afferent sensory transmission of SI cortex facilitated. 0.5 nM A-${\beta}$ with ST36 exerted much stronger effects than 0.5 nM A-${\beta}$ alone. 2. Application of $10{\mu}M$ A-${\beta}$ caused afferent sensory transmission of SI cortex unchangeable. But $10{\mu}M$ A-${\beta}$ with ST36 is facilitated at 30 min of post-drug period 3. Application of $10{\mu}M$ aA-${\beta}$ caused afferent sensory transmission of SI cortex diminished. $10{\mu}M$ aA-${\beta}$ with ST36 is diminished after 15min of post-drug period but is facilitated after 75min.

• Journal of Acupuncture Research
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• v.25 no.3
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• pp.179-187
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• 2008

Objectives & Methods : This study was to investigate effect of low frequency electroacupuncture on NADPH-d positive neurons in the brain cortex of rat with adjuvant induced rheumatoid arthritis. Experimental groups were divided into 6 groups ; Normal, Control, $ST_{36}$, $SP_9$, $ST_{36}+SP_9$ and Non-Acupoint. Normal group, non-arthritic group, was injected normal saline, and the other groups were injected FCA. Each acupoint groups were treated by 2Hz electroacupuncture at each acupoints and NA group was treated by 2Hz electroacupuncture at non-acupoint. Each groups were evaluated by the number of NADPH-d positive neurons in primary somatosensory area(S1), secondary somatosensory area(S2), motor area and caudate putamen by using an image analyzer and a microscope. Results : 1. In S1, the number of NADPH-d positive neuron cells in the $ST_{36}$ group were significantly(p<0.05) increased compared with the control group. 2. In S2, the number of NADPH-d positive neuron cells in all electroacupuncture groups were not significantly changed compared with the control group. 3. In motor area, the number of NADPH-d positive neuron cells in $ST_{36}$ group, $SP_9$ group, NA group were significantly(p<0.05) increased compared with the control group. 4. In Caudate putamen, the number NADPH-d positive neuron cells in all electroacupuncture groups were significantly(p<0.05) decreased compared with the control group. Conclusions : Our result demonstrated that low frequency electroacupuncture on $ST_{36}$ & $SP_9$ normalized expression of NADPH-d positive neurons in the brain cortex of the rheumatoid arthritis model in rats.