• Korean Journal of Cognitive Science
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• v.18 no.2
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• pp.139-157
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• 2007

We compared brain activation areas during participants drawn from contrasting two college majors performed intentionality detection (known as the basic mechanism of theory of mind) task using fMRI. The main purpose of this study was to identify whether individual differences are present in intentionality detection or not. In psychology major, the left inferior frontal gyrus, the fusiform gyrus, the superior temporal gyrus and the right fusiform gyrus, the supramarginal gyrus were activated. In engineering major, the inferior parietal lobule and the superior parietal lobule were found. This result suggests that according to participants' major, different brain areas were activated. The relations between performance of the intentionality detection task and the individual variants of participants were discussed.

• The Journal of Korean Association of Computer Education
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• v.13 no.6
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• pp.35-42
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• 2010

In this paper, the characteristics of online game addiction have been analyzed using fMRI. The fMRI images are taken from six target subjects who are around 20 years old, right-handed, and undergraduate male students with online game stimulations. The images are processed using SPM5, and statistical analysis showed following characteristics. First, online game stimuli produces an activation in BA18 of brain, and the Pearson correlation coefficient between the activation intensity of BA18 area and the addiction index value is very highly as .94. Second, the Pearson correlation coefficient is .75 between addiction index of subjects and activation index of the mesencephalon. From these observations, we found that the online game stimuli were processed as visual stimuli by subjects' brain, and the subject's brain with bigger addiction index processes more actively from the online game stimuli. Also, the online game stimuli activate the mesolimbic system, and therefore these findings may contribute for comparing the mechanism between general addiction and online game addiction.

• Science of Emotion and Sensibility
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• v.12 no.4
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• pp.425-432
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• 2009

The purposes of the study were to examine cerebellar areas and lateralization responsible for visuospatial and verbal tasks using functional Magnetic Resonance Imaging(fMRI). Eight healthy male college students($21.5\;{\pm}\;2.3$ years) and eight male college students($23.3\;{\pm}\;0.5$ years) participated in this fMRI study of visuospatial and verbal tasks, respectively. Functional brain images were taken from 3T MRI using the single-shot EPI method. All functional images were aligned with anatomical images using affine transformation routines built into SPM99. The experiment consisted of four blocks. Each block included a control task(1 minute) and a cognitive task(1 minute). A run was 8 minutes long. Using the subtraction procedure, activated areas in the cerebellum during the visuospatial and verbal tasks were color-coded by t-score. A cerebellar lateralization index was calculated for both cognition tasks using number of activated voxels. The activated cerebellar regions during the both cognition tasks of this study agree with previous results. Since the number of activated voxels of the left and right cerebellar hemisphere was almost same, there was no cerebellar lateralization for both cognition tasks.

• Progress in Medical Physics
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• v.26 no.2
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• pp.72-78
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• 2015

Organic solvents are known toxic effects like vertigo, behavioral obstacle, distracting, and peripheral neuropathy in neuron areas. However, there have been few studies how neurotoxic solvents-exposed workers are affected by the cognitive load of preceding working memory tasks. Therefore, we used fMRI as to measure the neural correlates of working memory impairment in occupational workers who had from chronic exposure to organic solvent. Twenty-nine solvent-exposed workers were included in this study. Each participant concluded the verbal N-back tasks (1- and 2-back) during the fMRI acquisition. Within-group analyses showed fronto-parietal networks were active in each condition. Direct comparisons between 1- and 2-back showed higher activation during the 2-back than 1-back. We found that increased activation of these regions at lower task demand is associated with increased cost of implementing.

• Investigative Magnetic Resonance Imaging
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• v.3 no.1
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• pp.78-83
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• 1999

Purpose : To evaluate the language areas activated by fMRI during different reading tasks and to assess the difference of activated areas according to each reading task. Materials and Methods : Functional maps of the language area were obtained during three reading tasks(Korean consonant letter, pseudoword, and word) in nine right-handed volunteers(7 males 2 females). MR examinations were performed at 1.5T scanner with EPI BOLD technique(gradient echo shot EPI, TR/TE 3000/60, flip angle $90^{\circ}$, matrix $64{\times}64$, 5mm thickness, no slice gap). Each task consisted of three resting periods and two activation periods and each period lasted 30 seconds. We used SPM program for the postprocessing of images and signification level was set at p<0.01. Activated areas were topographically analyzed in each stimulus. Results : Significant activated signals were demonstrated in all volunteers. Activated signals were seen in the frontal, temporal, parietal and occipital lobes during reading tasks and they were lateralized to the left hemisphere except occipital lobe. Letter and pseudoword produced stronger activated signals than word, and the activated signals were more lateralized to the left hemisphere in pseudoword reading than in letter reading. Conclusion : Activated signals were induced in the language areas by reading task of letter or wordform. Greater activation of language areas was induced when letter or pseudowords were presented than familiar words.

• Annals of Clinical Neurophysiology
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• v.1 no.1
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• pp.10-18
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• 1999

연구배경 및 목적 : 시각 인지 과정은 영장류 실험을 통하여 다소 정보를 얻을 수 있었으나 인간에서는 아직 완전하게 이해되지 않고 있다. 이 연구의 목적은 뇌자극과 시가유발전위 검사를 토대로 인간의 시각피질의 기능적 분화와 시간 순으로 활성화되는 양상을 보고자 한 것이다. 연구방법 : 간질 수술을 위하여 후두엽과 인접 부위에 광범위하게 피질하전극을 넣은 22명의 환자를 대상으로 전기적 뇌자극과 시각유발전위 검사를 시행하였다. 뇌자극시 나타나는 반응은 형태, 색, 및 움직임의 세 가지로 크게 나누고 형태는 다시 단순, 중간 및 복잡한 형태로 세분하였다. 시각유발전위는 P1 혹은 IV파의 latency를 측정하였다. 결과 : 단순 혹은 중간 형태는 흔히 occipital pole과 striate cortex에서 발생하였다. 색반응은 후두엽의 기저부 즉, fusiform, lingual, inferior occipital gyri를 자극할 때 관찰되었다. 움직임 반응은 내측기저부 및 외측의 측후두엽 혹은 측두정후두부의 경계부에서 주로 나타났다. 결론 : 이러한 결과는 인간의 시각피질이 시각의 여러 가지 구성성분 즉, 형태, 색, 및 움직임에 대해서 각각 별도로 분화되어 있다는 것을 보여준다. 도한 시각자극이 전해지면 striate cortex와 occipital pole이 가장 먼저 활성화되고 이어서 내측 및 외측 후두엽 부위가 활성화된다는 것을 알 수 있다. 이러한 사실을 종합하여 보면 인간의 시각피질은 시각의 여러 구성성분별로 별도로 발달된 해부학적 경로를 통하여 각각의 기능에 대하여 특수하게 분화된 뇌세포에서 시각정보를 각각 분석하되 일정한 시간순서에 의한다는 것을 시사하는 것이다.

• 한국HCI학회:학술대회논문집
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• 2006.02b
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• pp.815-819
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• 2006

가상현실에서 구현한 환경을 사용자가 실제처럼 느끼고 그 내용을 받아들이도록 하는 것은 중요한 목표이다. presence 는 "어떤 특정한 또는 이해할 수 있는 장소에 존재한다고 생각하는 인간의 지각" 상태를 나타낸다. 따라서 presence 는 가상환경에서 사용자가 얼마나 그 가상환경을 실제로느끼는지를 알 수 있는 중요한 파라미터 중 하나 이다. 또한 Presence 는 가상현실에서 경험하게 되는 여러가지 감각적인 정보들을 통하여 느끼는 종합적인 느낌을 반영하는 파라미터 이다. 따라서 같은 가상현실을 경험한다 할지라도 개인마다 느끼는 presence 는 차이가 있을 것이고 이러한 차이는 가상환경이 제공하는 정보의 차이에 대한 인식과 처리에 있어서도 영향을 미칠 것이다. 그러므로 이러한 차이는 관련된 뇌 영역의 활성화의 차이로 나타날 것이다. 가상현실 컨텐츠는 아바타를 통해서 정보를 전달하고 피험자가 그 내용을 바탕으로 생각해보는 내용으로 구성하였다. 아바타가 전달하는 내용은 명확하게 모든 정보를 알려주는 과제 와 중요한 정보를 생략하고 알려주는 과제 두 가지로 구성하였다. 그리고 피험자 개개인이 각각의 내용을 바탕으로 추론하는 동안 뇌 영역 활성화의 차이와 가상현실 경험 동안의 presence 점수와 관련된 뇌 영역을 알아보았다. 실험 결과 Right Lingual Gyrus (16, -95, 14), Left Lingual Gyrus (-15, -88, -16), Right Fusiform Gyrus (35, -81, -14), Right Lingual Gyrus (3, -67, 3), Left Inferior Temporal Gyrus (-43, -1, -36), Left Anterior Cingulate (0, -38, -10), Right Posterior Cingulate (2, -50, 10)에서 유의미한 상관 관계가 있었다.

• Journal of the Korea Convergence Society
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• v.12 no.12
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• pp.323-330
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• 2021

In this study, we intended to examine the difference in brain activation due to dominant and non-dominant hands using functional near-infrared spectroscopy(fNIRS) in 10 healthy adults. Box & Block Test(BBT) was conducted under two conditions: dominant hand and non-dominant hand. During the experiment, brain activity was measured using fNIRS and signals were analyzed using nirsLAB v2019.04 software after the experiment was completed. As a result, 6 out of 10 people showed activation of the cerebral hemisphere related to the dominant hand, and only 3 out of 10 people showed activation of the cerebral hemisphere related to the non-dominant hand. In other words, both dominant and non-dominant hand cconfirmed that the cerebral hemispheres related to dominant hands were more active. Therefore, it is believed that fNIRS can be used as a fundamental data applicable to children with sensory processing disorders that are difficult to identify dominant hand.

• Investigative Magnetic Resonance Imaging
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• v.9 no.1
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• pp.30-35
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• 2005

Purpose : The purpose of this study is to observe the blood oxygen level dependent (BOLD) contrast changes due to the reaction of human brain at a gustatory sense in response to a salty-taste stimulation. Materials and Methods : Twelve healthy, non-smoking, right-handed male subjects (mean age: 25.6, range: 23-28 years) participated in this salty-taste stimulus functional magnetic resonance (fMRI) study. MRI scans were performed with 1.57 GE Signa, using a multi-slice GE-EPI sequence according to a blood-oxy-gen-level dependent (BOLD) experiment paradigm. Scan parameters included matrix size $128\times128$, FOV 250 mm, TR 5000 msec, TE 60 msec, TH/GAP 5/2 mm. Sequential data acquisitions were carried out for 42 measurements with a repetition time of 5 sec for each taste-stimulus experiments. Analysis of fMRI data was carried out using SPM99 implemented in Matlab. NaCl solution $(3\%)$ was used as a salty stimulus. The task paradigm consisted of alternating rest-stimulus cycles (30-second rest, 15-second stimulus) for 210 seconds. During the stimulus period, NaCl-solution was presented to the subject's mouth through plastic tubes as a bolus of delivered every 5 sec using -processor controlled auto-syringe pump. Results : Insula, frontal opercular taste cortex, amygdala and orbitofrontal cortex (OFC) were activated by a salty-taste stimulation $(NaCl,\;3\%)$ in the fMRI experiments. And dosolateral prefrontal cortex (DLPFC) was also significantly responded to salty-taste stimuli. Activation areas of the right side hemisphere were more superior to the left side hemisphere. Conclusion : The results of this study well correspond to the fact that both insula, amygdala, OFC, DLPFC areas are established as taste cortical areas by neuronal recordings in primates. Authors found that laboratory-developed auto-syringe pump is suitable for gustatory fMRI study. Further research in this field will accelerate to inquire into the mechanism of higher order gustatory process.

• Journal of the Korea Computer Graphics Society
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• v.28 no.3
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• pp.101-111
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• 2022

Conditional autonomous vehicles should hand over control to the driver according on driving situations. However, if the driver is immersed in a non-driving task, the driver may not be able to make suitable decisions. Previous studies have confirmed that the cues enhance take-over performance with a directional information on driving. However, studies on the effect of take-over cues on the driver's brain activities are rigorously investigated yet. Therefore, this study we evaluates the driver's brain activity according to the take-over cue. A total of 25 participants evaluated the take-over performance using a driving simulator. Brain activity was evaluated by functional near-infrared spectroscopy, which measures brain activity through changes in oxidized hemoglobin concentration in the blood. It evaluates the activation of the prefrontal cortex (PFC) in the brain region. As a result, it was confirmed that the driver's PFC was activated in the presence of the cue so that the driver could stably control the vehicle. Since this study results confirmed that the effect of the cue on the driver's brain activity, and it is expected to contribute to the study of take-over performance on biomakers in conditional autonomous driving in future.