• Korean Journal of Cognitive Science
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• v.19 no.4
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• pp.397-417
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• 2008

We applied fMRI to examine brain activation during false-belief task in Korean healthy adults. In the first experiment, brain areas including bilateral precuneus, temoporo-parietal junction, left inferior parietal lobule, posterior cingulate, middle frontal gyrus were found during first -order false-belief task. In the second experiment, the left middle frontal gyrus, medial frontal gyrus and right precuneus, middle frontal gyrus, temoporo-parietal junction were activated during second-order false-belief task. These results are compatible with the suggestions that the ways in which adults understand theory of mind stories are universal.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.7 s.172
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• pp.200-207
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• 2005

This study compares two different methods of measuring brain-BOLD activation. By comparing two different methods of measurement i.e., one method calculating the neural activation area (the number of activated voxels), while the other measured the neural activation intensity (the mean intensity of selected activated yokels), this study identified the more precise method of measuring brain activation which results from the completion of a visuospatial task. 16 right-handed male college students (mean age 23.2 years) participated in this study as subjects. Functional brain images were scanned on them using a 3T MRI single-shot EPI method. No correlation was found between the levels of cognitive performance and number of activated yokels in the activated brain areas. However, a significant correlation was found between the levels of cognitive performance and the mean intensity of selected activated yokels in the parietal, frontal, and other areas. In conclusion, the method of mean intensity was considered a better index of brain activity rather than the activated yokels measurement method.

• Investigative Magnetic Resonance Imaging
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• v.9 no.2
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• pp.134-139
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• 2005

Purpose : To evaluate the usefulness of acoustic noise attenuator on auditory fMRI examination. Materials and methods : The acoustic noise attenuator consists of mask, earmuff and silicon earplug. The soft polyurethane sheet and polyurethane form , which has a good soundproof characteristic were used for mask and earmuff. Auditory fMRI experiments of 500 Hz pure tone stimulation were performed in three different cases; first all of mask, earmuff and earplug, secondly earmuff and earplug only and finally without attenuator in 4 normal hearing volunteers. For data acquisition, BOLD MR imaging technique was employed at a 1.5T MR scanner equipped with high performance gradient system. The raw data were analyzed using a SPM-99 analysis software and the activation maps were obtained. Results : In case of all items of acoustic attenuator used, the results revealed that activation was focused on primary auditory area. When only earmuff and earplug were used, the results showed that the activation spread over primary auditory and secondary associative areas. Last, when no device used, only weak activation was observed on the right auditory cortex. Conclusion : It is expected that the acoustic noise attenuator, which consists of earplugs, earmuffs and mask, is a very useful device in auditory fMRI study.

• Journal of Genetic Medicine
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• v.4 no.2
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• pp.179-185
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• 2007

Purpose : Catecholamines are the neuro-transmitters in the sympathetic nervous system (SNS) and are activated by stress stimulus. Tyrosine hydroxylase (TH) and Dopamine-${\beta}$-Hydroxylase (DBH) are very important enzymes in the catecholamine synthesis. Corticotropin releasing hormone (CRH) is released in the process of reacting to stresses. The aim of this study is to find out what effects immobilization stresses have on the expression of TH, BDH and CRH mRNA in a rat's brains. Methods : We compare expression levels in rat's brains of TH, DBH and CRH mRNA induced by immobilization stresses between the test group and controled group. The expression levels of TH, DBH and CRH mRNA are measured by RT-PCR and the Western Blotting Analysis (WBA). Results : In brains and adrenal glands of the immobilization stress group, the expression levels of TH and DBH mRNAs are significantly two to three times higher (P<0.01), and CRH mRNAs are approximately one and a half times higher (P<0.05) than those of controlled group. Conclusion : This study suggest that the expression levels of TH, DBH and CRH mRNAs are activated by stress stimulus in a rat's brains and adrenal glands.

• Proceedings of the Korean Society for Cognitive Science Conference
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• 2002.05a
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• pp.208-210
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• 2002

신경과 의사들은 실제 임상에서 환자들에게 대뇌피질감각의 이상 여부를 알기 위해 손바닥에 숫자나 문자를 쓰게 하여 알아 맞추게 하는 검사를 시행한다. 손바닥에 쓰여진 문자나 숫자를 인식하기 위해서는 몇 가지 단계의 인지과정이 필요할 것으로 생각된다. 첫번째로 손바닥에 닿는 감각을 인지해야 하고, 다음 단계로 이 감각들을 시공간적으로 통합하는 과정이 필요할 것이고, 이러한 정보들을 유지하면서 마지막 단계로 우리 머리 속에 있는 문자와 일치시키는 과정이 필요할 것이다. 본 연구에서는 위와 같은 가설 아래 각각에 해당할 수 있는 뇌영역을 밝히기 위해 기능적 뇌자기공명영상을 이용하였다. 손바닥의 일차적 감각을 인지하는 데는 일차감각영역이 활성화 되었고, 이차감각영역의 활성은 감각들의 시공간적 통합과 관련될 것으로 생각되었으며, 이것들을 유지하는 것은 작업기억의 하부구조인 시공간 그림판과 관련되는 영역이며, 문자를 일치시키는 과정은 브로카영역 부근의 활성과 관련되는 것으로 생각되었다. 위의 가설에 대한 추가검증 및 실제로 일어나는 인지과정에 대한 추가적인 연구가 필요할 것이다.

• Investigative Magnetic Resonance Imaging
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• v.3 no.2
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• pp.154-158
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• 1999

Purpose : The purpose of this study was to find the optimum TE value for enhancing $T_2^{*}$ weighting effect and minimizing the SNR degradation and to compare the BOLD effects according to the changes of TE in 1.5T and 3.0T MRI systems. Materials and Methods : Healthy normal volunteers (eight males and two females with 24-38 years old) participated in this study. Each volunteer was asked to perform a simple finger-tapping task (sequential opposition of thumb to each of the other four fingers) with right hand with a mean frequency of about 2Hz. The stimulus was initially off for 3 images and was then alternatively switched on and off for 2 cycles of 6 images. Images were acquired on the 1.5T and 3.0T MRI with the FLASH (fast low angle shot) pulse sequence (TR : 100ms, FA : $20^{\circ}$, FOV : 230mm) that was used with 26, 36, 46, 56, 66, 76ms of TE times in 1.5T and 16, 26, 36, 46, 56, 66ms of TE in 3.0T MRI system. After the completion of scan, MR images were transferred into a PC and processed with a home-made analysis program based on the correlation coefficient method with the threshold value of 0.45. To search for the optimum TE value in fMRI, the difference between the activation and the rest by the susceptibility change for each TE was used in 1.5T and 3.0T respectively. In addition, the functional $T_2^{*}$ map was calculated to quantify susceptibility change. Results : The calculated optimum TE for fMRI was $61.89{\pm}2.68$ at 1.5T and $47.64{\pm}13.34$ at 3.0T. The maximum percentage of signal intensity change due to the susceptibility effect inactivation region was 3.36% at TE 66ms in 1.5T 10.05% at TE 46ms in 3.0T, respectively. The signal intensity change of 3.0T was about 3 times bigger than of 1.5T. The calculated optimum TE value was consistent with TE values which were obtained from the maximum signal change for each TE. Conclusion : In this study, the 3.0T MRI was clearly more sensitive, about three times bigger than the 1.5T in detecting the susceptibility due to the deoxyhemoglobin level change in the functional MR imaging. So the 3.0T fMRI I ore useful than 1.5T.

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.501-506
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• 2008

본 연구에서는 가상현실을 이용한 단서노출치료가 흡연자의 니코틴 갈망수준을 감소시키는지를 알아보았다. 이를 위하여 8명의 흡연청소년을 대상으로 6회기의 가상환경 단서노출치료를 실시하였다. 또한 단서노출치료 실시전과 후에 흡연관련 사진과 중립사진을 제시하는 동안 참가자들의 뇌를 기능성 자기공명영상장치(fMRI)로 측정하였다. 그 결과 단서노출실시 전에는 prefrontal cortex(PFC), Anterior cingulate gyrus(ACC) 영역을 비롯한 7개의 영역이 활성화되었고, 단서노출치료 후에는 right middle frontal gyrus, right uncus, left medial frontal gyrus, right fusiform gyrus, 그리고 right superior frontal gyrus 영역이 활성화되었다. 단서노출치료 전과 후의 비교에 서는 PFC가 관찰되었다. 본 연구의 결과로 흡연자의 흡연 갈망은 감소되었으며, 가상현실단서노출치료는 흡연자들 뿐 아니라 여러 물질의존자들의 치료에 유용한 방법이 될 것이라는 것을 시사한다.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2009.05a
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• pp.71-72
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• 2009

행동활성화체계(BAS)/ 행동억제체계(BIS)는 서로 독립적이고 구분되는 신경 기저와 작용 방식을 가졌기 때문에 사람들은 이 두 체계에서 각기 독립적인 민감성을 보이리라고 가정할 수 있으며, 개인의 기질이나 성격 특성 및 광범위한 전반적 정서 경험 경향성과도 밀접하게 관련된다고 가정된다. 본 연구에서는 뇌자도(MEG)에서 취득한 신호를 가지고 EEG에서 얻은 신호 및 자기 보고식 질문지를 통한 비교 분석 연구를 수행하였다. 총 9명 (male=6, female=3)을 대상으로 EEG/MEG를 수행한 후 BIS/BAS 질문지를 수행하여 비교 분석하였다. 자기 보고식 질문지와 EEG/MEG와의 상관관계 및 통계분석을 통하여 EEG와 MEG에서 일치성 및 상관성을 살펴보고 향후 성격 및 감성성향 판단 및 분류에 있어서 MEG의 효용성 측면을 살펴보고자 함이 본 연구의 목적이다.

• Science of Emotion and Sensibility
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• v.14 no.3
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• pp.403-414
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• 2011

The current study examined brain regions associated with aesthetic experience to fractal images using functional MRI. The aesthetic estimations of the images showed that there is a general consensus regarding the perception of beautiful images. Out of 270 fractal images, fifty images rated highest(beautiful images) and fifty images rated lowest(non-beautiful images) were selected and presented to the participants. The two conditions were presented using the block design. Frontal lobes, cingulate gyri, and insula, the areas related to the cognitive and emotional processing in aesthetic experience, were activated when beautiful images were presented. In contrast, the middle occipital gyri and precuneus, the areas associated with experience of negative emotions, were activated when non-beautiful images were presented. The conjunction analysis showed activations in temporal areas in response to beautiful images and activations in parietal areas in response to non-beautiful images. These results indicate that beautiful images elicit semantic interpretations whereas non-beautiful images facilitate abstract processes.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.11a
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• pp.373-376
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• 2005

본 연구에서는 뇌의 반응과 말초신경계의 변화를 통하여 유머와 기쁨의 긍정적인 정서의 구분이 가능한가를 밝히고자 하였다. fMRI와 말초신경계 반응 측정 실험 각각을 수행하는 동안, 유머와 기쁨정서를 유발하는 동영상 자극(2분)이 제시되었고, 실험이 끝난 후 심리적인 평가도 함께 수행되었다. fURI 실험은 boxcar design으로 한 session 내에 두 block으로 구성되었다. 말초신경계 반응실험에서는 안정상태와 정서상태에서의 피부전기 반응을 측정하였다. fMRI 결과, 유머자극과 기쁨자극 제시 시 공통적으로 precentral Cortex, temporal Cortex, precuneus 가 활성화 되었고, 유머자극은 기쁨자극에 비하여 우측 middle temporal cortex, 우측 inferior frontal cortex, 좌측 middle frontal cortex 에서 큰 활성화를 보였다. 피부전기 반응(EDA) 분석 결과 두 정서 모두 안정상태에 비하여 유의하게 증가하였고, 유머자극은 기쁨자극에 비하여 피부전도수준(SCL)과 피부전도반응의 수(NSCR)에서 유의하게 증가하는 것으로 나타났다.