• 전자공학회논문지
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• 제50권9호
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• pp.179-185
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• 2013

본 논문에서는 시각에 대해 반응하는 운동 행동의 효과를 분석하기 위해서 응답속도정합-유발전위(RTA-ERP: Response Time Aligned-Event Related Potential)를 모델링하고, RTA-ERP의 진폭과 응답 속도를 이용하여 사이먼 효과를 분석하였다. 건강한 성인 15명(남성 9명, 여성 6명, 평균 연령 31세)을 대상으로, 같은 숫자에 대한 다른 숫자를 찾아 반응하는 '양자극방안' 실험을 7분 동안 수행하였다. 실험결과 제안된 RTA-ERP는 기존의 ERP에 비해 뇌에서의 처리시간 차이에 따른 변이를 보상할 수 있었으며, 향상된 LRP(Lateralized Readiness Potential)와 Pe(Error Related Positivity)를 나타내었다. '일치', '불일치' 시험 패턴에 대하여 '일치'에 대한 RTA-ERP의 진폭과 응답속도는 각각 '불일치'보다 컸으며 진폭은 $0.03{\mu}V$ 크고 반응속도는 43 ms 만큼 빨랐다. 응답속도에 따른 동기 시점을 보정하여 정합함에 따라, RTA-ERP의 진폭특성은 사이먼 효과의 특징인 ERP의 P300 진폭과 대응함을 확인하였다.

• 한국안전학회지
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• 제15권1호
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• pp.167-175
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• 2000

Work performance and human error are complicated phenomena so that it is very difficult to grasp the true nature of them. However, Event Related Potential (ERP) may give a clue to them because human brain reflects diverse psychophysiological process. In the present study, the possibility of ERP application to the ergonomic area was evaluated in view of grasping error symptoms. For that purpose, the subjects were asked to count specific characters in a random character matrix on a computer monitor, and their ERP was compared with their performance data. Based upon the results, the amplitude of P300 was not so high as that in the case of the Odd Ball tasks, correct response corresponded with stable ERP with high P300 amplitude whereas wrong response did with unstable, fluctuating ERP with low P300 amplitude. Those results coincided with the work performance, and it was concluded that 3-wave fluorescent with illumination level of 800 lux would be recommendable for the counting task in concern. Conclusively, ERP including P300 might supply an objective clue to the problem of human errors in cognitive process.

• 한국지능시스템학회논문지
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• 제19권1호
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• pp.122-127
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• 2009

본 논문에서는 피험자가 A, B, C, D 글자를 말하는 상상을 할 때 사고중추에서와 Broca's area 에서 EEG 신호를 측정하였으며 이 신호를 Event-Related Spectral Perturbation (ERSP), Inter-Trial Coherence (ITC) 그리고 Event Related Potential (ERP) 방법을 통해 분석하여 보았다. 그 결과 F7, FT7 영역의 뇌파에서 각 문자를 보여주는 자극 제시 후 0$\sim$300ms 동안의 1$\sim$13Hz에서 높은 coherence를 보였으며, P300 이 뚜렷하게 나타나는 것을 확인할 수 있었다. 하지만 ERP를 통해 분석해본 결과 각 글자에 대한 차이를 구분하고자 하였던 처음 연구의 동기와 달리 각 글자를 말할 때 ERP가 약간의 차이를 보이기는 하였으나 각 문자에 대한 차이라거나 이 차이를 통해 문자를 구별할 수 있다고 하기는 어려웠다. 하지만 본 논문에서는 이 실험결과를 통해 기존에 운동관련 뇌 영역에 국한되어 있던 BCI 연구의 한계를 극복하고 보다 다양한 서비스를 제공할 수 있는 응용 시스템을 제안하였다.

• 대한의용생체공학회:의공학회지
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• 제29권6호
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• pp.477-483
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• 2008

The observations of difference and similarity in brain activities involved in processing different languages have fundamental importance in cognitive neuroscience. The purpose of this study was to investigate the difference and similarity in temporal brain activation patterns due to the language difference during visual perception of Korean and English words under priming. Especially, we tried to find the difference in evoked spectral power in gamma-band, which is known to reflect feature binding. The stimulation was visually presented as word pairs belonging to same or different categories so that N400 event-related potential(ERP) was evoked. Average ERP analysis and spectral analysis of gamma-band activity(GBA) were performed on 12 normal Korean subjects. Several ERP components such as P1, N1, N400, and P600 could be identified consistently, and the differences in N1, N400, and P600 were observed. From the spectral analysis, we found that the evoked GBA(eGBA) was significantly larger for English at ${\sim}100$ ms poststimulus. The latency of the eGBA was also considerably delayed for English. Overall, the results on the ERP components and eGBA analyses seem to be commensurate with subjects' familiarity of each language, and the difficulty of perceiving words of each language. The methods of this study can also be applied for clinical purposes considering that the language-related processing can be greatly altered for the patients with neurological or psychiatric diseases.

• 대한의용생체공학회:의공학회지
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• 제29권1호
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• pp.73-81
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• 2008

The purpose of this study is to observe the brain activity patterns during visual oddball tasks with two difficulty levels by the analysis of high-density event-related potential (ERP). Along with conventional statistical analysis of averaged ERP waveforms, we applied independent component analysis (ICA) for the individual, single-trial analysis and verified its effectiveness. We could identify multiple ERP components such as early visual components (P1, N1), and two components which seem to be important task-related components and showed difficulty-dependent variability (P2, P300). The P2 was found around central region at $180{\sim}220ms$, and the P300 was found globally at $300{\sim}500ms$ poststimulus. As the task became difficult, the P2 amplitude increased, and the P300 amplitude decreased. After single-trial ERPs were decomposed into multiple independent components (ICs), several ICs resulting from P2 and P300 sources were identified. These ICs were projected onto scalp electrodes and the projected ICs were statistically compared according to two task difficulties. For most subjects, the results obtained from single-trial/individual analysis using ICA gave the tendencies of amplitude change that are similar to the averaged ERP analysis for most subjects. The temporal pattern and number of ICs corresponding to ${\mu}$ rhythm was not dependent on the task difficulty. It seems that the motor response was not affected by the task difficulty.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2002년도 추계학술대회 논문집
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• pp.148-152
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• 2002

This study is to develop the Alzheimers disease (AD) detection and analysis system using event-related potential (ERP) of AD patients. We recorded ERP in an auditory oddball paradigm in mild AD (n=25), severe AD (n=12), age-matched normal aged controls (n=17), and young controls (n=7). The amplitude and latency of target P300 components were compared among 4 groups. The relationship between P300 measures and neuro psychological test (K-DRS) scores were evaluated by correlations. The latency of P300 was prolonged in AD and the effects were correlated with the severity of dementia. The P300 amplitude was not affected significantly in AD. Theres no difference between normal aged group and young group. These results suggest that the P300 component is specifically affected by Alzheimer type dementia.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제32권3호
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• pp.93-98
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• 2021

Electroencephalography (EEG) measures neural activation due to various cognitive processes. EEG and event-related potentials (ERPs) are widely used in studies investigating psychopathology and neural substrates of psychiatric diseases in children and adolescents. The present study aimed to review recent ERP studies in child and adolescent psychiatry. ERPs are non-invasive methods for studying synaptic functions in the brain. ERP might be a candidate biomarker in child-adolescent psychiatry, considering its ability to reflect cognitive and behavioral functions in humans. For the EEG study of psychiatric diseases in children and adolescents, several ERP components have been used, such as mismatch negativity, P300, error-related negativity (ERN), and reward positivity (RewP). Regarding executive functions and inhibition in patients with attention-deficit/hyperactivity disorder (ADHD), P300 latency, and ERN were significantly different in patients with ADHD compared to those in the healthy population. ERN showed meaningful changes in patients with anxiety disorders, such as generalized anxiety disorder, separation anxiety disorder, and obsessive-compulsive disorder. Patients with depression showed significantly attenuated RewP compared to the healthy population, which was related to the symptoms of anhedonia.

• 생물정신의학
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• 제13권3호
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• pp.137-143
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• 2006

One of the most widely recognized neurophysiologic endophenotypes for schizophrenia is deficient gating or inhibition of the P50 component of the auditory event-related potential(ERP). A deficit in P50 sensory gating refers to a dysfunction in the mechanism responsible for modulating the brain's sensitivity of filtering out irrelevant or background stimuli, perhaps as a result of dysfunction in inhibitory neural circuits. In this paper, we review the neuronal and genetic aspects as well as medication effects on P50 in schizophrenia.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.283-287
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• 1993

We constructed morphological filter for single sweep records of event-related potential (ERP), especially P300 waveform. By combining 4 basic operations; erosion, dilation, opening and closing, we can derive any desired filters whose property fits the current objectives. The morphological filter for single sweep records of ERP was constructed by taking account of the features of the signal and noise components. The morphological filter has superior properties of separating the signal ancl the noise even existing within a same frequency band. The constructed morphological filter was tested by using simulation data of ERP and then applied to actual ERP data of a normal subject. The results proved that the constructed morphological filter was an appropriate tool for single sweep records of ERP.

• 대한의용생체공학회:의공학회지
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• 제27권4호
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• pp.170-179
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• 2006

The purpose of this study was to investigate the spatiotemporal cortical activation pattern and functional connectivity during visual perception of words. 61 channel recordings of electroencephalogram were obtained from 15 subjects while they were judging the meaning of Korean, English, and Chinese words with concrete meanings. We examined event-related potentials (ERP) and applied independent component analysis (ICA) to find and separate simultaneously activated neural sources. Spectral analysis was also performed to investigate the gamma-band activity (GBA, 30-50 Hz) which is known to reflect feature binding. Five significant ERP components were identified and left hemispheric dominance was observed for most sites. Meaningful differences of amplitudes and latencies among languages were observed. It seemed that familiarity with each language and orthographic characteristics affected the characteristics of ERP components. ICA helped confirm several prominent sources corresponding to some ERP components. The results of spectral and time-frequency analyses showed distinct GBAs at prefrontal, frontal, and temporal sites. The GBAs at prefrontal and temporal sites were significantly correlated with the LPC amplitude and response time. The differences in spatiotemporal patterns of GBA among languages were not prominent compared to the inter-individual differences. The gamma-band coherence revealed short-range connectivity within frontal region and long-range connectivity between frontal, posterior, and temporal sites.