• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.71-74
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• 1997

MR acoustic sound or noise due to gradient pulsings has been one of the problems in MRI, both in patient scanning as well as in many areas of psychiatric and neuroscience research, such as brain fMRI. Especially in brain fMRI, sound noise is one of the serious noise sources which obscures the small signals obtainable from the subtle changes occurring in oxygenation status in the cortex and blood capillaries. Therefore, we have studied the effects of acoustic or sound noise arising in fMR imaging of the auditory, motor and visual cortices. The results show that the acoustical noise effects on motor and visual responses are opposite. That is, for the motor activity, it shows an increased total motor activation while for the visual stimulation, corresponding (visual) cortical activity has diminished substantially when the subject is exposed to a loud acoustic sound. Although the current observations are preliminary and require more experimental confirmation, it appears that the observed acoustic-noise effects on brain unctions, such as in the motor and visual cortices, are new observations and could have significant consequences in data observation and interpretation in future fMRI studies.

• BMB Reports
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• 제41권1호
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• pp.23-28
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• 2008

The altered amino acid (AA) levels as neurotransmitter closely correlate to neurodegenerative conditions including Alzheimer's disease (AD). Target profiling analysis of nineteen AAs in brain cortex samples from three Tg2576 mice as AD model and three littermate mice as control model was achieved as their N(O,S)-ethoxycarbonyl/tert-butyldimethylsilyl derivatives by gas chromatography. Subsequently, star pattern recognition analysis was performed on the brain AA levels of AD mice after normalization to the corresponding control median values. As compared to control mice, $\gamma$-aminobutyric acid among ten AAs found in brain samples was significantly reduced (P < 0.01) while leucine was significantly elevated (P < 0.02) in AD mice. The normalized AA levels of the three AD mice were transformed into distorted star patterns which was different from the decagonal shape of control median. The present method allowed visual discrimination of the three AD mice from the controls based on the ten normalized AA levels.

• 제어로봇시스템학회논문지
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• 제11권12호
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• pp.1083-1087
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• 2005

As development of digital technology, many kinds of multimedia data are used variously and requirements for effective use by user are increasing. In order to transfer information fast and precisely what user wants, effective retrieval method is required. As existing multimedia data are impossible to apply the MPEG-1, MPEG-2 and MPEG-4 technologies which are aimed at compression, store and transmission. So MPEG-7 is introduced as a new technology for effective management and retrieval of multimedia data. In this paper, we extract content-based features using color descriptor among the MPEG-7 standardization visual descriptor, and reduce feature data applying PCA(Principal Components Analysis) technique. We model the cerebral cortex and hippocampal neural network in engineering domain, and team content-based feature vectors fast and apply the hippocampal neural network algorithm to compose of optimized feature. And then we present fast and precise retrieval effect when indexing and retrieving.

• Journal of Korean Neurosurgical Society
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• 제41권6호
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• pp.421-424
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• 2007

Two patients, one with glioblastoma multiforme [GM] in the right thalamus and the other with meningioma at the right frontal convexity, had suffered bilateral cortical blindness after transtentorial herniation. On one of those patients, bilateral cortical blindness had occurred due to acute obstructive hydrocephalus caused by GM and on the other patient, cortical blindness had developed after acute hemorrhage from meningioma. Bilateral occipital lobes of those patients showed signal change on the brain magnetic resonance image [MRI]. There were no ophthalmologic abnormalities on fundoscopy and ophthalmologic examination. After recovery of consciousness, cortical blindness was detected in both patients, and during gradual recovery period, visual function was slowly recovered. The pattern of visual evoked potential [VEP] at 7 weeks and 12 weeks after herniation was normalized gradually. Cortical blindness due to herniation was reversible, even though the high signals of bilateral visual cortex still existed on MRI 16 month later in case 2.

• 약학회지
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• 제36권3호
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• pp.269-277
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• 1992

The effects of ginseng saponins on the distribution of nerve cells in cerebral cortex of carbon monoxide (CO)-intoxicated mice were studied in the young ($5{\sim}8$ weeks) and aged ($43{\sim}52$ weeks) mice. Mice were exposed to 5000 ppm of CO for 40 minutes (72% HbCO). After that, nerve cells in motor(area 4), somatosensory(area 3) and visual(area 17) area of cerebral cortex was observed. In young mice, the number of nerve cells in each area was significantly decreased on 1st, 7th and 14th day after CO intoxication. In aged mice, that was also decreased after CO intoxication. Especially the number of the nerve cells in motor and somatosensory area was significantly decreased on 1st and 7th day, while that in visual area was decreased only on 1st day. The number of nerve cells in young mice pretreated with ginseng saponins were significantly decreased less on 7th and 14th day than that of untreated mice. The number of nerve cells in each area of normal aged mice was larger than that of normal young mice. The results suggest that CO exposure causes local degeneration or disturbance of nerve cells and delayed neurologic sequelae, while ginseng saponins might play a role of protective action on the nerve cells which were damaged by CO.

• 정보처리학회논문지B
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• 제18B권5호
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• pp.305-314
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• 2011

사람의 의도를 인지하기 위해 감정을 시각적으로 인식하는 연구는 전통적으로 감정을 드러내는 얼굴 표정을 인식하는 데 집중해 왔다. 최근에는 감정을 드러내는 신체 언어 즉 신체 행동과 자세를 통해 감정을 나타내는 방법에서 감정 인식의 새로운 가능성을 찾고 있다. 본 연구는 신경생리학의 시각계 처리 방법을 적용한 신경모델을 구축하여 행동에서 기본 감정 의도를 인식하는 방법을 제안한다. 이를 위해 시각 피질의 정보 처리 모델에 따라 생물학적 체계의 신경모델 검출기를 구축하여 신체 행동의 정적 자세에서 6가지 주요 기본 감정을 판별한다. 파라미터 변화에 강건한 제안 모델의 성능은 신체행동 자세 집합을 대상으로 사람 관측자와의 평가 결과를 비교 평가하여 가능성을 제시한다.

• Annals of Clinical Neurophysiology
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• 제8권1호
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• pp.44-47
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• 2006

Background: The present study used magnetoencephalography (MEG) to investigate the neural substrates for modified version of Treisman's visual search task. Methods: Two volunteers who gave informed consent participated MEG experiment. One was 27- year old male and another was 24-year-old female. All were right handed. Experiment were performed using a 306-channel biomagnetometer (Neuromag LTD). There were three task conditions in this experiment. The first was searching an open circle among seven closed circles (open condition). The second was searching a closed circle among seven uni-directionally open circles (closed condition). And the third was searching a closed circle among seven eight-directionally open circles (random (closed) condition). In one run, participants performed one task condition so there were three runs in one session of experiment. During one session, 128 trials were performed during every three runs. One participant underwent one session of experiment. The participant pressed button when they found targets. Magnetic source localization images were generated using software programs that allowed for interactive identification of a common set of fiduciary points in the MRI and MEG coordinate frames. Results: In each participant we can found activations of anterior cingulate, primary visual and association cortices, posterior parietal cortex and brain areas in the vicinity of thalamus. Conclusions: we could find activations corresponding to anterior and posterior visual attention systems.

• 디지털융복합연구
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• 제12권11호
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• pp.349-355
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• 2014

본 논문은 인간의 생물학적 시각정보처리과정 특성과 웨이블릿을 이용한 인공시각시스템을 제안한다. 인공시각시스템은 인간의 생물학적 시각정보 처리과정을 이용하며 맹인의 인공시각시스템 제작 및 일반적인 인식시스템에 적용할 수 있다. 본 논문에서는 인간의 망막에서 신경절 세포까지 정보 처리과정을 모델링하여 구성하였고 신경절 세포에서 후두엽 초기시각피질까지 전달되는 정보 복원과정을 모델링하여 초기시각피질에 표현되는 영상정보를 구성하였다. 실험과정은 인간의 시각정보 처리과정 특성인 저주파, 고주파 분해를 웨이블릿 변환으로 시각 정보를 구현하였고 이를 이용하여 인식 시스템에 적용하였다. 실험에 사용한 데이터는 AT&T 얼굴데이터베이스를 사용하였다. 그리고 제안하는 인간의 시각정보처리 과정 특성을 이용한 방법이 영상인식 시스템의 정확성을 향상시킬 수 있음을 실험을 통하여 증명하고자 한다.

• 대한전자공학회논문지
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• 제20권3호
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• pp.6-12
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• 1983

시각 자극을 주었을 때 이에 유발되어 나타나는 전위를 두피에 19개의 전극을 부착하고 측정하여 500Hz의 표본화 주파수로 A/D변환하였다. 이들 전위들의 분포로부터 각 전극의 좌표에 의해서 결정된 웨이팅 매트릭스를 사용하여 전위 분포의 중심점을 구하고 시간에 따른 이동 상태를 5명의 대상인과 4명의 비정상인에 대하여 분석하였다. 정상인에게서는 자극에 의한 시각적 정보가 시신경 경로를 통해서 전기적 신호로 전달되는 형태를 파악할 수 있었고, 비정상인의 경우에는 이러한 현상이 나타나지 않는 것을 발견하였다. 또한 본 연구의 중심점 추적의 방법과 다이폴 소오스 모델, 포인트 소오스 모델과의 관계를 검토 분석하였다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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• pp.620-623
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• 2003

The TAM (Topographic Attentive Mapping) network is a biologically-motivated neural network. Fuzzy rules are acquired from the TAM network by the pruning algorithm. In this paper we formulate a new input layer using Gabor function for TAU network to realize receptive field of human visual cortex.