• The Journal of Korean Physical Therapy
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• 제21권4호
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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.

• Annals of Clinical Neurophysiology
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• 제23권1호
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• pp.7-16
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• 2021

Transcranial magnetic stimulation (TMS) is a safe and noninvasive tool for investigating the cortical excitability of the human brain and the neurophysiological functions of GABAergic, glutamatergic, and cholinergic neural circuits. Neurophysiological biomarkers based on TMS parameters can provide information on the pathophysiology of dementia, and be used to diagnose Alzheimer's disease and differentiate different types of dementia. This review introduces the basic principles of TMS, TMS devices and stimulating paradigms, several neurophysiological measurements, and the clinical implications of TMS for Alzheimer's disease.

• Annals of Clinical Neurophysiology
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• 제13권1호
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• pp.38-43
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• 2011

Background: In the brain, the dominant primary motor cortex (M1) has a greater hand representation area, shows more profuse horizontal connections, and shows a greater reduction in intracortical inhibition after hand exercise than does the non-dominant M1, suggesting a hemispheric asymmetry in M1 plasticity. Methods: We performed a transcranial magnetic stimulation (TMS) study to investigate the hemispheric asymmetry of paired associative stimulation (PAS)-induced M1 plasticity in 9 right-handed volunteers. Motor evoked potentials (MEPs) were measured in the abductor pollicis brevis (APB) muscles of both hands, and MEP recruitment curves were measured at different stimulation intensities, before and after PAS. Results: MEP recruitment curves were significantly enhanced in the dominant, but not the non-dominant M1. Conclusions: These results demonstrate that the dominant M1 has greater PAS-induced plasticity than does the non-dominant M1. This provides neurophysiological evidence for the asymmetrical performance of motor tasks related to handedness.

• 대한임상검사과학회지
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• 제51권4호
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• pp.468-474
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• 2019

뇌심부자극술은 뇌심부핵에 고주파 전기자극을 전달하여 약물 불응성 이상운동질환을 치료하는 효과적인 방법이다. 그리고 미세전극기록은 뇌심부자극 수술 중에 MRI와 함께 뇌심부핵의 위치를 정확히 파악하여 수술 결과를 향상시키고 부작용을 최소화 할 수 있는 보조적인 검사이다. 본 논문의 목적은 이상운동질환에 대한 뇌심부자극 수술 중에 실시한 미세전극기록을 분석하여 신경생리학적 파형과 유용성을 알아보고자 하였다. 2018년 1월부터 12월까지 이상운동질환에 대한 뇌심부자극 수술 중에 미세전극기록를 실시한 환자 대상으로 후향적 조사를 하였다. 총 28명의 환자 중에 시상하핵은 38 개의 MER, 내측 담창구는 10개의 MER, 복내측 시상핵은 4개의 MER을 실시했다. 모두 목표지점을 찾았고 미세자극을 이용해서 부작용의 여부를 확인하고 목표지점을 재조정하였다. 수술 후 총 28명의 환자에서 모두 임상 증상은 호전되었다. 결론적으로. 미세전극기록은 신경생리학적 파형을 이용해서 MRI와 함께 정확한 뇌심부핵 부위를 파악해서 이상운동질환에 대한 뇌심부자극 수술 결과를 향상시키고 부작용을 최소화할 수 있는 유용한 검사이다.

• 융합신호처리학회논문지
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• 제8권4호
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• pp.227-236
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• 2007

유비쿼터스 시대의 도래에 따른 서비스의 고급화는 다양한 형태의 사용자 단말기의 개발을 유도하였으며, 이러한 사용자 단말기의 변화는 다양한 형태의 인간친화형 사용자 인터페이스의 개발로 이어지게 되었다. 이러한 다양한 형태의 인간친화형 사용자 인터페이스 중, 인간의 뇌를 활용한 사용자 인터페이스, 즉, BCI에 관한 연구가 최근 산발적으로 다양하게 진행되고 있다. 현재 진행되어지고 있는 다양한 형태의 BCI 관련 연구들은, 연구 초기 수준을 극복하지 못하는 실정이며, 이러한 연구개발의 지체 이유로는 체계적인 연구가 진행되어지지 않고 있다는 점을 들 수 있다. 대부분의 HCI 또는 BCI 관련 연구들은 생체신호를 수집하여 신호처리 과정을 거치게 되며, 이때 중요한 연구요소중의 하나로 DB구축 분야를 들 수 있다. 하지만 현재 진행되고 있는 대부분의 BCI 관련 연구의 경우 DB구축부터 시작한 체계적인 연구가 이루어지고 있지 않는 실정이다. 뇌파를 제외한 다른 생체신호, 즉 오감자극을 활용한 HCI 연구와는 달리, 뇌파 DB의 경우 피험자를 제외한 다른 연구 관련자들은 현재 피험자로부터 수집되어지고 있는 DB가 실험에 필요한 적절한 신호인지 구분하기 힘든 실정이다. 또한, 뇌파 신호의 수집 시 연구관련 자들은 피험자에게 정확한 지침을 제시하지 못하고 있는 실정이며 어떠한 방법으로 피험자가 실험에 집중하여야 확연한 패턴을 보이는 차별화 된 뇌파 신호의 생성이 가능한지 명확하게 알려지지 않은 실정이다. 따라서 본 논문에서는 뇌파를 활용한 BCI구현과 사용자 의지에 따른 활용 시 보다 정확하고 높은 인식률 구현을 하기 위한 기초 연구 방안으로 정확하고 효율적인 뇌파 DB구축 시스템을 제안한다. 또한 현재까지 명확하게 알려지지 않은 효과적인 뇌파생성 방안을 동시에 연구하기 위하여 오감자극을 활용한 뇌파 DB 수집이 가능한 구축 시스템을 구현하며 각 방법에 따라 구축되어진 뇌파의 패턴 분석을 통한 효율적인 뇌파 DB구축 방안을 제안한다.

• 대한의용생체공학회:의공학회지
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• 제31권5호
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• pp.359-364
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• 2010

The purpose of the brain-computer (machine) interface (BCI or BMI) is to provide a method for people with damaged sensory and motor functions to use their brain to control artificial devices and restore lost ability via the devices. Functional electrical stimulation (FES) is a method of applying low level electrical currents to the body to restore or to improve motor function. The purpose of this study was to develop a SSVEP-based BCI rehabilitation training system with FES for spinal cord injured individuals. Six electrodes were attached on the subjects' scalp ($PO_Z$, $PO_3$, $PO_4$, $O_z$, $O_1$ and $O_2$) according to the extended international 10-20 system, and reference electrodes placed at A1 and A2. EEG signals were recorded at the sampling rate of 256Hz with 10-bit resolution using a BIOPAC system. Fast Fourier transform(FFT) based spectrum estimation method was applied to control the rehabilitation system. FES control signals were digitized and transferred from PC to the microcontroller using Bluetooth communication. This study showed that a rehabilitation training system based on BCI technique could make successfully muscle movements, inducing electrical stimulation of forearm muscles in healthy volunteers.

• The Journal of Korean Physical Therapy
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• 제24권2호
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• pp.127-133
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• 2012

Purpose: This study aims to examine the power changes in eletrocenphalogram (EEG) detected from the tibialis anterior muscle, during repetitive contraction exercise in normal female adults. Methods: The subjects of this study were 24 normal adult females, with no musculoskeletal or nervous system disorders. The 24 female subjects were divided into two groups: 12 subjects comprised a voluntary stimulation training group, and the other 12 subjects comprised an electrical stimulation training group. A total of thirty contractions were made repetitively by each woman, with maximal voluntary contraction exercise for six seconds, and a resting time of three seconds. During the experiment, their EEG was measured at eight positions. The eight positions were Fpz, Fz, Cz, CPz, C3, C4, P3, and P4, in accordance with the international 10~20 system. Results: The relative alpha power and beta power showed no statistically significant differences between the two groups. But the relative gamma power of the CPz, C3, C4, P3, and P4 areas showed statistically significant differences between the two groups (p<0.05). The relative theta power of the C4 area showed statistically significant differences between the two groups (p<0.05). Conclusion: Our findings show that tibialis anterior muscle contraction by electrical stimulation and by voluntary repeated contraction differentially affected brain activation. In particular, the CPz, C3, C4, P3 positions of relative gamma power showed brain activation in voluntary contraction. The C4 position of relative theta power showed different brain activation between the two groups.

• 감성과학
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• 제3권2호
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• pp.29-40
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• 2000

Autonomic and EEG responses were analyzed in 32 college students exposed to visual stimulation with Korean Affective Picture System (KAPS) and 36 students exposed to the International Affective Picture System (IAPS). Cardiac, electrodermal, and electrocortical measures were recorded during 30 sec of viewing affective pictures. The slides intended to elicit basic emotions (fear, anger, surprise, disgust, and sadness) were presented to subjects via Kodak slide-projector. The aim of the study was to differentiate autonomic and EEG responses associated with the same negative valence emotions elicited by KAPS and IAPS stimulation and to identify the influence of cultural relevance on physiological reactivity. The analysis of obtained results revealed significant differences in physiological responsiveness to emotionally negative valence slides from KAPS and IAPS. The typical response profile for all emotions elicited by the KAPS included HR acceleration (except surprise), and increase of electrodermal activity, slow and fast alpha blocking and fast beta power increase in EEG, which was not associated with significant asymmetry (except fast alpha in sadness). Stimulation with the IAPS evoked HR deceleration, specific electrodermal responses with relatively high tonic electrodermal activation, alpha-blocking and fast beta increase, and was accompanied also by theta power increase and marked frontal asymmetry (e.g., fast beta, theta asymmetries in sadness, fast alpha in fear). Physiological responses to fear and anger-eliciting slides from the IAPS were significantly less profound and were accompanied by autonomic and EEG changes more typical for attention rather than negative affect. Higher cardiovascular and electrodermal reactivity to fear emotion observed in the KAPS, e.g., as compared to data with the IAPS as stimuli, can be explained by cultural relevance and higher effectiveness of the KAPS in producing certain emotions such as fear in Koreans.

• Journal of Acupuncture Research
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• 제23권5호
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• pp.199-206
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• 2006

Objectives : The aim of this study was to investigate the effect of various electroacupuncture stimulation on neuronal nitric oxide synthase(nNOS) in cerebral cortex, brain stem, cerebellum of spontaneously hypertensive rats. Methods : We evaluated the changes of nNOS-positive neurons using a immunohistochemical method. The staining intensity of nNOS positive neurons was assessed in a quantitative fashion using a microdensitometrical method based on optical density by means of an image analyzer. Results : The average optical density of nNOS-positive neurons of 100 Hz (bipolar square wave 0.2 ms duration and 100 Hz frequency) electroacupuncture treatment group significantly decreased in most cortical areas comparison between the manual acupuncture and 2 Hz (bipolar square wave 0.2 ms duration and 2 Hz frequency) electroacupuncture groups. In the brain stem, the optical density of nNOS-positive neuron at superficial gray layer of the superior colliculus area, dorsolateral periaqueductal gray area and paralemniscal nucleus were same as cerebral cortex. Conclusion : We conclude that the morphological evidence for nNOS-positive neurons may be have regional change in cerebral cortex brain stem and cerebellum according to various electroacupuncture stimulations.

• 감성과학
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• 제8권2호
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• pp.155-160
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• 2005

본 연구는 관절통 모델에서 웅담 우황과 웅담 우황 사향의 약침액의 효과를 검사하기 위해 수행되었다. 할로탄 마취하에서 관절통은 수컷 쥐의 관절강내에 $2\%$ carrageenan을 주입하여 유발시켰다. 운동자극에 대한 감각신경의 반응은 약침을 시술하기 전과 후에 기록하였다. 경혈에 주입한 약침은 유해한 운동 자극에 대한 신경의 반응을 억제시켰다 족삼리에 시술한 약침은 합곡에 비해 유해한 자극에 대한 관절 감각신경의 반응을 더 많이 억제시켰다. 이러한 결과는 웅담 우황과 웅담 우황 사향의약침이 관절통을 완화하는 데 효과적인 치료법을 제공할 수 있다는 것을 시사한다.