• The KIPS Transactions:PartB
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• v.9B no.1
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• pp.35-46
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• 2002

The EEG is a time series of electrical potentials representing the sum of a very large number of neuronal dendrite potentials in the brain. The collective dynamic behavior of neural mass of different brain structures can be assessed from EEG with depth electrodes measurements at regular time intervals. In recent years, the theory of nonlinear dynamics has developed methods for quantitative analysis of brain function. In this paper, we considered it is reasonable or not for ICA apply to EEG analysis. Then we applied ICA to EEG for big toe movement and separated the independent components for 15 samples. The strength of each independent component can be represented on the topological map. We represented ICA can be applied for time and spatial analysis of EEG.

• Journal of Digital Contents Society
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• v.7 no.1
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• pp.15-23
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• 2006

The hamonious development of human brain has been an indigenous objective of each age. A variety of training programs related to the purpose have turned up at an educational market and a commercial market, as well. I'd like to indicate, however, that these training methods are somewhat prejudiced and have some elements, inherently, which are against the development of human brain for one's whole personality. Therefore, the most desirable brain training program is to induce it to respond to various stimuli, to educate for itself and to generate continuously, to create and strengthen an innumerous synapse among brain cells, so as to form a nero-network. In this study, I have used a brain training program with multimedia which have been produced for a specific purpose. With this method, by measuring directly the effectiveness of human brain development, I have analysed more objectively and more quantitatively.

• Journal of Digital Contents Society
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• v.18 no.2
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• pp.239-247
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• 2017

In the past, delivering knowledge mainly, education focused on the development of left brain. However, as the importance of right brain is widely accepted, various approaches on education in creativity have been tried. With the advance in the research on the brain, it has been known that the left brain and the right brain are closely linked to work effectively while they are specialized to some functionalities differently. We developed an educational content exploiting Chinese characters to facilitate the balanced development of both brain. Making categorizations from Yin-yang and five elements of the universe, it consists of four stages. The first stage is to stimulate the brain with visual scandal. The second one, third one, and the fourth one are to develop the right brain, left brain, and both brain respectively. Through expert interview, the potential of the developed content as an efficacious method for brain development was verified.

• Korean Journal of Acupuncture
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• v.31 no.1
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• pp.20-32
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• 2014

Objectives : There has been some controversy about the modulatory effects on brain function during acupuncture on each side of the same acupoint. This study was designed to investigate and compare the blood oxygen level-dependent(BOLD) responses of acupuncture on each side of ST36. Methods : Fourteen healthy subjects were recruited for imaging and received acupuncture or placebo stimulations either on the left or on the right acupoint of ST36 in each scan. For the voxel-wise statistical analysis, one sample T-test and the within-subject analysis of variance(ANOVA) test were performed using SPM8 software. Results : This study showed that acupuncture on each side of ST36 showed different BOLD signal patterns. Higher BOLD responses after acupuncture stimulations at the left ST36 compared to the right were observed mainly in the parahippocampal gyrus(BA 28), dorsolateral prefrontal cortex(DLPFC, BA 44), thalamus, culmen and claustrum. We investigated the different neural responses between rest and activation periods of placebo and acupuncture stimulations on each side of ST36. Acupuncture at the right ST36 elicited activation mainly in the insula, supplementary motor area(SMA) and anterior cingulate cortex(ACC), while acupuncture at the left ST36 elicited activation mainly in the insula, primary somatosensory cortex(SI, BA 2) and DLPFC(BA 44). Conclusions : To our knowledge, this is the first reported functional MRI study directly comparing when needling at the right and at the left side of ST36. This study's preliminary results proved to be evidence of acupuncture's different effects when performed on opposite sides of an acupoint.

• Investigative Magnetic Resonance Imaging
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• v.3 no.1
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• pp.47-52
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• 1999

Purpose : The purpose of this study was aimed to evaluate the BOLD(blood oxygen level dependent) contrast fMRI(functional MR imaging) in the occipital lobe and to compare with the metabolic changes based on H MRS (MR spectroscopy) and MRSI (MR spectroscopic imaging) before and after visual stimulation Materials and Methods : Healthy human volunteers (eight males and two females with 24-30 year age) participated in this study. All of the BOLD fMRI were acquired on a 1.5T MR with EPI during supervised visual stimulation in the occipital lobe. The red flicker with 8Hz was used for visual stimulation. After imaging acquisition, the MR images were transferred into unix workstation and processed with acquired from the same location based on the activation map. MRSI (magnetic resonance spectroscopic imaging) was also acquired to analyze the lactate changes before and after stimulation. Results : The activation maps were successfully produced by BOLD effect due to visual stimulation. NAA (N-acetyle aspartate)/Cr (creatine) ratio varied only from $1.79{\pm}0.28{\;}to{\;}1.88{\pm}0.20$ in activation area before and after stimulation. However, the signal intensity of lactate was elevated $9.48{\pm}4.38$ times higher than before activation. Lactate metabolite images were consistent with the activation maps. Conclusion : The BOLD contrast fMRI is enough sensitive to detect the activated area in human brain during the visual stimulation. Lactate metabolite map presents the evidence of lactate elevation on the same area of activation.

• Korean Journal of Cognitive Science
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• v.21 no.2
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• pp.359-386
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• 2010

In order to evaluate the domain-specific model and process-specific model of spatial and nonspatial working memory (WM), this study manipulated the memory load of the delayed response task and examined how the neural correlates of memory load effect was influenced by the stimulus domain (face and location) at the maintenance stage of WM using an event-related fMRI experiment. One or three face stimuli were presented as target stimuli and participants were asked to maintain the face itself (face WM) or the location of face stimuli (spatial WM). The results of recognition judgment accuracy showed no difference between face WM and spatial WM, and showed equivalent memory load effects of both WM. As a result of brian image analysis, memory load effect at maintenance stage showed that inferior, middle, and superior PFC were recruited by both face WM and spatial WM, and showed that VLPFC was the commonly activated area by both WM, supporting functional specialization of PFC by process components of WM. This study provides evidence for process-specific model in which maintenance of WM is associated with VLPFC.

• Science of Emotion and Sensibility
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• v.16 no.4
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• pp.527-534
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• 2013

In this study, we analyzed spatial-frequency relationship related brain function for change of the time during attentional visual stimulus through the analysis of Coherence. With experimentation about ERP(Event Related Potential)data, it revealed that change of the phase synchronization between different scalp locations at ${\theta}$, ${\alpha}$ band. ERP between left and right frontal lobes, between the frontal and central lobes showed the phase synchronization at the P100, N200, ERP between the frontal and occipital lobes showed the phase synchronization at the P300 related information of visual stimulus. Compared to STFT using the window of a fixed length, CWT is able to multi-resolution analysis with the adjustment of parameters of mother wavelet. Thus, coherence results with CWT was found to be effective for analysis of time-varying spatial-frequency relationship in ERP. The phase synchronization for inattentional visual stimulus was not observed.

• Science of Emotion and Sensibility
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• v.16 no.4
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• pp.503-508
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• 2013

This study aims to analyze using RQA(Recurrence Quantification Analysis) about difference of electroencephalogram between inattention and attention among nonlinear methods for school age children who need attention. The experiments were conducted by 21 healthy subjects(12 males and 9 females). Inattention state is 500msec before the beginning of the auditory stimuli, attention state is 500msec after the beginning of auditory stimuli. The results of RQA parameters are greater in attention state than inattention state. It showed a statistically difference(p < 0.05). According to two states, auditory evoked potentials are displayed RP and CRP in diagram form to confirm nonlinear characteristics and The brain dynamics in the attention is more complex than the inattention. It is feasible that the RQA can be useful for the analysis of complex brain dynamics associated during auditory attentional task.

• The Journal of the Acoustical Society of Korea
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• v.40 no.3
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• pp.228-233
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• 2021

In this paper, we propose a method to extract and classify features of multi-channel ElectroEncephalo Graphy (EEG) that change according to various musical tempo stimuli. In the proposed method, a 3D convolutional bidirectional gated recurrent neural network extracts spatio-temporal and long time-dependent features from the 3D EEG input representation transformed through the preprocessing. The experimental results show that the proposed tempo stimuli classification method is superior to the existing method and the possibility of constructing a music-based brain-computer interface.

• Science of Emotion and Sensibility
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• v.5 no.4
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• pp.67-75
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• 2002

The purpose of this study is to assess the ability of balance control in virtual moving surround stimulation using head mount display (HMD) device and force platform in patients with brain injury. Fifteen patients with stroke (mean age 54.47 yrs) and fifteen healthy normal persons participated. COP parameters were obtained total path distance, frequency of anterior-posterior and medial-lateral component by FFT analysis, weight-spectrum analysis in the two different conditions; (1) during comfortable standing with opened or closed eyes, (2) during virtual moving surround stimulation delivered using HMD with four different moving pattern. Moving patterns consisted of close-far, superior-inferior lilting (pitch) , right-left tilting (roll) and horizontal rotation (yaw) movement. In all parameters, the test-retest reliability was high. Also, the construct validity of virtual moving surround stimulation was excellent (p＜0.05). A posturographic balance assessment system equiped with virtual moving surround stimulation using HMD is considered clinically useful in evaluation of balance control in patients with brain injury.