• 감성과학
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• 제20권4호
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• pp.101-112
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• 2017

We investigated the neural representation of reward probability recognition and its neural connectivity with other regions of the brain. Using functional magnetic resonance imaging (fMRI), we used a simple guessing task with different probabilities of obtaining rewards across trials to assay local and global regions processing reward probability. The results of whole brain analysis demonstrated that lateral prefrontal cortex, inferior parietal lobe, and postcentral gyrus were activated during probability-based decision making. Specifically, the higher the expected value was, the more these regions were activated. Fronto-parietal connectivity, comprising inferior parietal regions and right lateral prefrontal cortex, conjointly engaged during high reward probability recognition compared to low reward condition, regardless of whether the reward information was extrinsically presented. Finally, the result of a regression analysis identified that cortico-subcortical connectivity was strengthened during the high reward anticipation for the subjects with higher cognitive impulsivity. Our findings demonstrate that interregional functional involvement is involved in valuation based on reward probability and that personality trait such as cognitive impulsivity plays a role in modulating the connectivity among different brain regions.

• The Journal of Korean Physical Therapy
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• 제15권3호
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• pp.295-345
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• 2003

This study investigated activation of cerebral cortex in patients with hemiplegia that was caused by neural damage. Key-point control movement therapy of Bobath was performed for 9 weeks in 3 subjects with hemiplegia and fMRI was used to compare and analyze activated degree of cerebral cortex in these subjects. fMRI was conducted using the blood oxygen level-dependent(BOLD) technique at 3.0T MR scanner with a standard head coil. The motor activation task consisted of finger flexion-extension exercise in six cycles(one half-cycles = 8 scans = $3\;sec{\times}\;8\;=\;24\;sec$). Subjects performed this task according to visual stimulus that sign of right hand or left hand twinkled(500ms on, 500ms off). After mapping activation of cerebral motor cortex on hand motor function, below results were obtained. 1. Activation decreased in primary motor area, whereas it increased in supplementary motor area and visual association area(p<.001). 2. Activation was observed in bilateral medial frontal gyrus, middle frontal gyrus of left cerebrum, inferior frontal gyrus, inter-hemispheric, fusiform gyrus of right cerebrum, superior parietal lobule of parietal lobe and precuneus in subjedt 1, parahippocampal gyrus of limbic lobe and cingulate gyrus in subject 2, and inferior frontal gyrus of right frontal lobe, middle frontal gyrus, and inferior parietal lobule of left cerebrum in subject 3 (p<.001). 3. Activation cluster extended in declive of right cellebellum posterior lobe in subject 1, culmen of anterior lobe and declive of posterior lobe in subject 2, and dentate gyrus of anterior lobe, culmen and tuber of posterior lobe in subject 3 (p<.001). In conclusion, these data showed that Key-point control movement therapy of Bobath after stroke affect cerebral cortex activation by increasing efficiency of cortical networks. Therefore mapping of brain neural network activation is useful for plasticity and reorganization of cerebral cortex and cortico-spinal tract of motor recovery mechanisms after stroke.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제19권2호
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• pp.117-139
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• 2015

For the purpose of determining neurophysiological mechanism of math anxiety, we conducted an EEG measurement for 22 sixth grade elementary students including 11 students with high math anxiety (HMA group), and 11 students with low math anxiety (LMA group). We found that in HMA group, delta wave was significantly generated from the right frontal lobe, and in LMA group, four paths are clearly connected while they perform math tasks (right inferior occipital gyrus ${\leftrightarrow}$ left superior parietal lobule /left middle frontal gyrus ${\leftrightarrow}$ left inferior parietal lobule /left middle frontal gyrus ${\leftrightarrow}$ right inferior parietal lobule / right middle frontal gyrus ${\leftrightarrow}$ right inferior parietal lobule). According to the above results we suggest that math anxiety is related to emotions associated with pain, reduces working memory and has a negative effect on math performance.

• The Journal of Korean Physical Therapy
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• 제27권3호
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• pp.135-139
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• 2015

Purpose: The aim of this study was to compare EEG topographical maps in patients with chronic stroke after action observation physical training. Methods: Ten subjects were recruited from a medical hospital. Participants observed the action of transferring a small block from one box to another for 6 sessions of 1 minute each, and then performed the observed action for 3 minutes, 6 times. An EEG-based brain mapping system with 32 scalp sites was used to determine cortical reorganization in the regions of interest (ROIs) during observation of movement. The EEG-based brain mapping was comparison in within-group before and after training. ROIs included the primary sensorimotor cortex, premotor cortex, superior parietal lobule, inferior parietal lobule, superior temporal lobe, and visual cortex. EEG data were analyzed with an average log ratio in order to control the variability of the absolute mu power. The mu power log ratio was in within-group comparison with paired t-tests. Results: Participants showed activation prior to the intervention in all of the cerebral cortex, whereas the inferior frontal gyrus, superior frontal gyrus, precentral gyrus, and inferior parietal cortex were selectively activated after the training. There were no differences in mu power between each session. Conclusion: These findings suggest that action observation physical training contributes to attaining brain reorganization and improving brain functionality, as part of rehabilitation and intervention programs.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2008년도 학술대회 1부
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• pp.728-732
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• 2008

본 연구는 운동 표상에 관한 뇌 메커니즘의 이해를 위해 fMRI를 이용한 측정 시스템을 개발하였다. 개발된 시스템의 검증을 위해 예비 실험을 시행하였다. fMRI task는 visual feedback을 제공하는 task와 차단하는 task 두 가지의 task로 구성되었다. 실험 결과 visual feedback이 제공되었을 때는 left superior orbital gyrus, bilateral precentral gyrus, left superior occipital gyrus, left supplementary motor area, right thalamus, right postcentral gyrus 그리고 right superior parietal lobule 같은 영역들이 활성화 되었다. Visual feedback이 차단되었을 때는 left precuneus, right middle temporal gyrus, bilateral supplementary motor area, right anterior cingulate cortex, left Inferior temporal gyrus, left insula lobe, right superior parietal lobule, bilateral postcentral gyrus 그리고 left precentral gyrus 같은 영역들이 활성화 되었다. 개발된 시스템을 통해서 visual feedback이 차단되었을 경우 운동 표상에 관한 뇌 메커니즘을 알아 볼 수 있었다.

• Korean Journal of Radiology
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• 제22권12호
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• pp.2052-2061
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• 2021

Objective: The role of preoperative overt hepatic encephalopathy (OHE) in the neurophysiological mechanism of cognitive improvement after liver transplantation (LT) remains elusive. This study aimed to explore changes in sub-regional thalamic functional connectivity (FC) after LT and their relationship with neuropsychological improvement using resting-state functional MRI (rs-fMRI) data in cirrhotic patients with and without a history of OHE. Materials and Methods: A total of 51 cirrhotic patients, divided into the OHE group (n = 21) and no-OHE group (n = 30), and 30 healthy controls were enrolled in this prospective study. Each patient underwent rs-fMRI before and 1 month after LT. Using 16 bilateral thalamic subregions as seeds, we conducted a seed-to-voxel FC analysis to compare the thalamic FC alterations before and after LT between the OHE and no-OHE groups, as well as differences in FC between the two groups of cirrhotic patients and the control group. Correction for multiple comparisons was conducted using the false discovery rate (p < 0.05). Results: We found abnormally increased FC between the thalamic sub-region and prefrontal cortex, as well as an abnormally decreased FC between the bilateral thalamus in both OHE and no-OHE cirrhotic patients before LT, which returned to normal levels after LT. Compared with the no-OHE group, the OHE group exhibited more extensive abnormalities prior to LT, and the increased FC between the right thalamic subregions and right inferior parietal lobe was markedly reduced to normal levels after LT. Conclusion: The renormalization of FC in the cortico-thalamic loop might be a neuro-substrate for the recovery of cognitive function after LT in cirrhotic patients. In addition, hyperconnectivity between thalamic subregions and the inferior parietal lobe might be an important feature of OHE. Changes in FC in the thalamus might be used as potential biomarkers for recovery of cognitive function after LT in cirrhotic patients.

• Journal of Acupuncture Research
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• 제18권2호
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• pp.18-26
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• 2001

Purpose : To evaluate the effects of electroacupuncture on regional cerebral blood flow (rCBF) at acupoints suggested by oriental medicine to be related to the treatment of cerebrovascuiar diseases. Materials and Methods : Rest/electroaeupuncture-stimulation Tc-99m ECD brain SPECT using a same-dose subtraction method was performed on 5 normal male volunteers (age range from 27 to 30 years) using electroacupuncture at acupoint, ST 36. In the control study, needle location was chosen on a non-meridian focus 1cm posterior to the right fibular head. All images were spatially normalized and the differences between rest and acupuncture stimulation were statistically analyzed using SPM$^{(R)}$ for Windows$^{(R)}$. Results : Electroacupuncture applied at ST36 increased rCBF in the left hemisphere, that is, the left parietal lobe(angular gyrus), the left temporal lobe, the left inferior frontal lobe around rectus gyrus and the left cerebellar hemisphere, a part of the left inferior frontal lobe. In the control stimulation, no significant rCBF increase was observed. Conclusion : The results demonstrate that electroacupuncture increases rCBF in the contralateral cerebral hemisphere.

• Journal of Acupuncture Research
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• 제18권6호
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• pp.93-104
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• 2001

Objective : To localize and compare the cerebral regions- activated by the the stimulation of traditional and burning acupunctures in right Hap-Kok (LI4) acupoints. Methods : Thirty-four healthy normal volunteers (19 males, 15 females, age 31${\pm}$11 years) were studies by rest/acupuncture Tc-99m HMPAO SPECT using same-dose sequential injection method using right Hap-Kok(LI4), traditional and burning acupunctures. All images were spatially normalized and the differences between rest and acupuncture activation state were statistically analyzed using SPM 96. Results : Statistical analysis of the effect by the stimulation using traditional acupuncture in right L14 showed regional cerebral perfusion increase in right inferior frontal lobe, right straight gyrus, left anterolateral frontal lobe, left anteroinferior temporal lobe, left posterior temporal lobe, and left cerebellum. In the stimulation using burning acupuncture in right LI4, regional cerebral perfusion increased in right posterior prefrontal lobe, right precental gyrus, right postcentral gyrus, right poteroinferior temporal lobe, left precentral gyrus, left Broca's area, left anterior parietal lobe, left posterior prefrontal lobe, and left cerebellum. In right LA, diffuse perfusion increase were noted in the both inferior frontal lobe by traditional acupuncture compared to burning acupuncture. Conclusion : The results localized the cerebral areas showed the effect of the acupuncture on cerebral blood flow. The effects of traditional and burning acupunctures on cerebral blood flow were similar in right Hap-Kok (LI4) acupoints. But the effects of traditional acupunctures on cerebral blood flow are stronger than those of burning acupunctures on cerebral blood flow.

• 대한핵의학회지
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• 제19권1호
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• pp.145-148
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• 1985

A small number of pathologic entities such as Budd-Chiari Syndrome, cirrhosis, focal nodular hyperplasia, and superior and inferior vena cava obstruction has been reported to result in focal areas of increased uptake of radiocolloid on the hepatoscintigram. We recently studied a patient with focal accumulation of $^{99m}Tc-phytate$ at the inferior aspect of the liver, at the junction of the right and left lobe. The superior vena cava scintiangiogram was taken for the evaluation of the superior vena cava obstruction and collateral circulations. As a result of superior vena caval obstruction a considerable amount of blood flowed to the liver through the anterior parietal and periumblical venous channels. A certain fraction of radiocolloid delivered by the rete mirabile perfused to a localized area of the liver. This would explain the hot spot around the porta hepatis in this case.

• Nuclear Medicine and Molecular Imaging
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• 제42권1호
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• pp.17-28
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• 2008

목적: 파킨슨병 환자의 뇌혈류는 일반적으로 정상 또는 미만성의 혈류 감소를 보이는 것으로 보고하고 있다. 하지만 임상 상황에서 파킨슨 환자의 뇌관류 SPECT 결과를 판독할 때 다양한 뇌혈류 양상을 보이는 것을 발견할 수 있다. 이에 본 연구에서는 파킨슨병 환자의 뇌혈류 양상을 뇌관류 SPECT와 SPM 프로그램을 이용하여 나이, 성별, 신경심리 검사에 따라 어떤 차이가 있는지 보았고, 뇌혈류 양상을 유사한 형태끼리 나누어 보았다. 대상 및 방법: 치매가 동반되지 않은 파킨슨병으로 진단된 환자 219명(평균 $62.9{\pm}6.9$세, 남자 70명, 여자 140명)과 대조군으로 질병에 대한 과거력이 없는, 55명(평균 $61.4{\pm}9.2$세, 남자 15명, 여자 40명)을 대상으로 $^{99m}Tc$-HMPAO 뇌관류 SPECT를 실시하였고 SPM을 이용하여 환자군 정상 대조군을 비교하였다. 결과: 첫 번째로 전체 대조군에 비해 전체 환자군에서 좌측 하전두이랑, 좌측 뇌섬엽, 자측 가로측두이랑, 좌측 하두정소엽, 좌측 상두정소엽, 우측 쐐기전소엽, 우측 미상핵꼬리에 혈류 감소를 보였다. 두 번째로 성별에 따른 환자군과 정상춘의 비교에서 전반적으로 남, 여 환자 모두 좌반구의 혈류 감소가 우측에 비해 넓은 영역을 보였고, 남자 환자에 비해 여자 환자에서 좀 더 넓은 영역의 혈류 감소를 보였다. 세 번째로 나이에 따른 환자군과 정상군의 비교에서 50세 이하 환자군 에서는 주로 양쪽 후두엽, 두정엽과 좌측 측두엽에 정상인에 비해서 혈류 감소를 보였고 나이가 증가함에 따라 후두엽, 두정엽의 뇌혈류는 정상으로 나타났으며 양쪽 전두엽, 측두엽, 변연엽의 혈류 감소가 주로 관찰되었다. 네 번째로 뇌혈류가 저하되어 있는 영역을 기준으로 환자를 나누었을 때, 전두엽에 주로 감소되어 있는 환자 45명(20.6%) 측두엽에 주로 감소되어 있는 환자 38명(17.4%), 두정엽 39명(17.9%). 후두엽 40명(18.3%), 미만성으로 감소되어 있는 환자 14명(6.4%), 뇌혈류가 정상인 환자 32명(14.7%), 위의 형태로 분류하기 어려운 경우 10명(4.6%)으로 분류할 수 있었다. 마지막으로 신경심리검사에서 유사한 결과를 보이는 환자들끼리 분류하여 뇌혈류를 보았을 때 신경심리검사와 뇌혈류 양상사이에서 시공간 기능 항목 외에 특별한 상관관계는 발견할 수 없었고, 다시 연령별로 환자를 분류하여 신경심리검사결과와 뇌혈류 양상의 관계를 비교하여 보았을 때 일정 부분에서 유사한 양상을 관찰할 수 있었다. 결론: 파킨슨병 환자의 뇌혈류는 성별과 나이에 따라 다양한 국소적 혈류 저하의 소견을 보였고, 뇌혈류 양상에 따라 환자를 분류할 수 있었다.