• 제목/요약/키워드: Event-related potential

검색결과 148건 처리시간 0.026초

시각 자극의 집중에 따른 시간 변화에 대한 뇌 유발전위의 공간 - 주파수간 상관 변화 분석 (Spatial - Frequency Analysis of time-varying Coherence using ERP signals for attentional visual stimulus)

  • 이벽진;유선국
    • 감성과학
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    • 제16권4호
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    • pp.527-534
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    • 2013
  • 본 연구에서는 코히어런스 분석을 통하여 시각집중 기간 동안 시간 변화에 대한 뇌기능과 관련된 공간-주파수간 연관관계를 해석하였다. 집중관련 시각자극 실험 데이터를 통해 ${\theta}$${\alpha}$ 대역에서 서로 다른 두피 위치간 위상연관변화를 확인하였다. 좌우 전두엽, 전두엽과 두정엽 간 뇌유발전위는 P100, N200지점에서 위상동조를 보였으며, 전두엽과 후두엽 간 뇌유발전위는 시각 처리 정보가 반영되는 P300지점에서 위상동조를 보였다. 고정된 길이의 창을 이용하는 단구간 푸리에 변환에 비하여 연속 웨이블릿 변환은 모 웨이블릿의 파라미터 조정을 통한 다중해상도 분석이 가능하였다. 따라서 연속 웨이블릿 변환을 이용한 코히어런스 결과가 시간변화에 대한 뇌유발전위의 공간-주파수간 연관관계의 변화를 확인하는데 유효함을 확인하였다. 비 집중 자극수행에 대해서는 위상동조 현상이 나타나지 않았다.

현행 전국과학전람회의 실태 및 개선방안에 관한 연구 (A Study of the Status and Improvements of the National Science Fairs)

  • 최도성;한효의
    • 한국초등과학교육학회지:초등과학교육
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    • 제20권1호
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    • pp.59-73
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    • 2001
  • The National Science Fairs has been held in every year for the promotion of science and technology and scientific civil life. The purpose of this study is to survey the current problems in National Science Fairs by making up a question and to improve them. The study makes up a questionnaires about the existing Science Fairs to the teachers who have submitted their works to the Science Fairs and suggest the ways of improvement. The result of questionnaires is that little availability of reference materials, difficulty of paying proper attention to regular classes because of frequent travels, and absence of experimental devices and experimental rooms are perceived as major obstacles in preparing for the exhibition. Respondents teacher also pointed out some problems with the current organization of the exhibition; non-voluntary selection process for the potential authors, separation of research content from regular teaching materials, unrealistically high standard, low participation rate of teachers, so many exhibited works, lack of professionalism in the screening process. The majority however, agreed that the exhibition event should be continuously done, after remedial measures have been taken about the problems. First, the side of science education is emphasized in a purpose of the science fairs to let activity related to science fair be closely connected with school education. Second, students have to be divided according to grade. Third, research level have to be set not too higher than regular instruction content. Fourth, hand book related to science fairs have to be manufactured and spread. Fifth, data of local science fair have to be arranged. Sixth, judging section have to be subdivided and people related to science education have to be included to a judge. Seventh, excellent works have to be support to participate in ISEF.

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Cyclic Dipeptides from Bacillus vallismortis BS07 Require Key Components of Plant Immunity to Induce Disease Resistance in Arabidopsis against Pseudomonas Infection

  • Noh, Seong Woo;Seo, Rira;Park, Jung-Kwon;Manir, Md. Maniruzzaman;Park, Kyungseok;Sang, Mee Kyung;Moon, Surk-Sik;Jung, Ho Won
    • The Plant Pathology Journal
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    • 제33권4호
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    • pp.402-409
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    • 2017
  • Cyclic dipeptides (CDPs) are one of the simplest compounds produced by living organisms. Plant-growth promoting rhizobacteria (PGPRs) also produce CDPs that can induce disease resistance. Bacillus vallismortis strain BS07 producing various CDPs has been evaluated as a potential biocontrol agent against multiple plant pathogens in chili pepper. However, plant signal pathway triggered by CDPs has not been fully elucidated yet. Here we introduce four CDPs, cyclo(Gly-L-Pro) previously identified from Aspergillus sp., and cyclo(L-Ala-L-Ile), cyclo(L-Ala-L-Leu), and cyclo(L-Leu-L-Pro) identified from B. vallismortis BS07, which induce disease resistance in Arabidopsis against Pseudomonas syringae infection. The CDPs do not directly inhibit fungal and oomycete growth in vitro. These CDPs require PHYTOALEXIN DEFICIENT4, SALICYLIC ACID INDUCTION DEFICIENT2, and NONEXPRESSOR OF PATHOGENESIS-RELATED PROTEINS1 important for salicylic acid-dependent defense to induce resistance. On the other hand, regulators involved in jasmonate-dependent event, such as ETHYLENE RECEPTOR1, JASMONATE RESPONSE1, and JASMONATE INSENSITIVE1, are necessary to the CDP-induced resistance. Furthermore, treatment of these CDPs primes Arabidopsis plants to rapidly express PATHOGENESIS-RELATED PROTEIN4 at early infection phase. Taken together, we propose that these CDPs from PGPR strains accelerate activation of jasmonate-related signaling pathway during infection.

웨이블릿 특징 벡터 기반 SVM을 이용한 ERP 검출 알고리즘에 관한 연구 (Study on ERP Detection Algorithm Using SVM with wavelet feature vector)

  • 이영석
    • 한국정보전자통신기술학회논문지
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    • 제10권1호
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    • pp.9-15
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    • 2017
  • 본 연구에서는 웨이블릿 평면에서 대역 분할된 데이터를 특징 벡터로 하는 SVM을 이용한 ERP 검출 실험을 하였다. 뇌파 신호는 SCSD의 SCCN 뇌파 데이터베이스에 있는 시각적 자극(visual stimulus)을 이용하여 발생한 ERP를 사용하였다. 검출 알고리즘을 이용한 실험은 기존의 뇌파의 주파수 분석 데이터를 특징 벡터로 하는 방법과 웨이블릿 평면에서 전개된 뇌파 데이터를 특징 벡터로 하는 SVM 검출 방식을 비교하였다. 실험 결과는 기존의 특징 벡터를 이용하는 방법에 비하여 웨이블릿 평면에서 전개된 특징 벡터를 이용하는 SVM 방식이 EPR의 검출 율에서 약 10%의 향상된 성능을 나타내었다. 실험 결과에 대한 분석에서 웨이블릿 평면 특징 벡터를 적용한 SVM 실험 결과에서 검출율이 향상된 이유로서 대뇌 피질 활동이 ERP의 주파수 대역에 따른 활동성의 증감 특성과 ERP의 웨이블릿 평면 대역별 특성에 대한 비교 분석을 수행하였다.

사건관련전위를 이용한 정서 Go/NoGo과제에서 나타난 정신병질집단의 반응억제: 예비 연구 (An Event-Related Potential Investigation of Response Inhibition in Psychopathy using Emotional Go/NoGo Tasks : A Preliminary Study)

  • 김영윤
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2011년도 춘계 종합학술대회 논문집
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    • pp.361-362
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    • 2011
  • 본 연구는 사건관련전위를 이용하여 정신병질자들이 정서인식에 따른 반응억제의 어려움이 있는지를 알아보기 위해 수행되었다. 교도소에 수용 중인 수형자들을 대상으로 PCL-R(Psychopathy Checklist-Revised)의 점수에 따라 6명의 정신병질 수형자집단과 4명의 정상 수형자집단을 선별하고, 얼굴자극을 이용한 시각 Go/NoGo 과제를 실시하였다. 모든 피험자들은 Go 자극에 버튼을 누르고 NoGo 자극에 버튼을 누르지 않도록 지시를 받았으며, 과제를 실시하는 동안 사건관련전위를 측정하였다. 과제 1에서는 공포표정을 NoGo자극으로 사용하고 중성표정을 Go자극으로 사용하였으며, 과제 2에서는 슬픈 표정을 NoGo자극으로 사용하고 중성표정을 Go자극으로 사용하였다. 정신병질 수형자집단은 공포표정의 NoGo P3 진폭이 중성표정의 Go P3 진폭보다 크게 나타난 반면에 정상 수형자집단은 공포표정과 중성표정 간의 P3 요인의 진폭이 유사하거나 공포표정의 NoGo P3 진폭보다 중성표정의 Go P3 진폭이 더 크게 나타났다. P3 잠재기를 분석한 결과, 정신병질 수형자집단은 슬픔 표정자극의 NoGo조건에서 중성표정자극의 Go조건보다 느린 P3 잠재기를 나타낸 반면, 정상 수형자집단은 NoGo조건에서 Go조건보다 빠른 P3 잠재기를 나타냈다. 정서인식검사결과, 정신병질 수형자집단은 정상 수형자 집단보다 유의미하게 낮은 정확도를 나타냈다. 이러한 결과는 정신병질자들이 공포, 슬픔과 같은 부정적인 정서를 인식한 후에 반응을 억제하는데 인지적인 어려움을 겪는다는 것을 보여준다.

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긍정, 부정 감정 유발 시각자극에 의한 감마-대역 신경동기화 증가 (Increased Gamma-band Neural Synchrony by Pleasant and Unpleasant Visual Stimuli)

  • 여동훈;최정우;김경환
    • 대한의용생체공학회:의공학회지
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    • 제39권2호
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    • pp.94-102
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    • 2018
  • It is known that gamma-band activity (GBA) and phase synchrony (GBPS) are induced by emotional visual stimuli. However, the characteristics of GBA and GBPS according to different emotional states have not been identified. The purpose of this study is to investigate the changes in gamma-band neuronal synchronization induced by positive and negative emotional visual stimuli using electroencephalograms (EEGs). Thirteen healthy male subjects have participated in the experiment. The induced spectral power in gamma-band was the highest for negative stimuli, and the lowest for neutral stimuli in 300-2,000 ms after the stimulus onset. The inter-regional phase synchronization in gamma-band was increased in 500-2,000 ms, mainly between the bilateral frontal regions and the parieto-occipital regions. Larger number of significant connections were found by negative stimuli compared to positive ones. Judging from temporal and spatial characteristics of the gamma-band activity and phase synchrony increases, the results may imply that affective visual stimuli cause stronger memory encoding than non-emotional stimuli, and this effect is more significant for negative emotional stimuli than positive ones.

Interval estimate of physiological fluctuation of peak latency of ERP waveform based on a limited number of single sweep records

  • Nishida, Shigeto;Nakamura, Masatoshi;Suwazono, Shugo;Honda, Manabu;Nagamine, Takashi;Shibasaki, Hiroshi
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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    • pp.1.1-5
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    • 1994
  • In the single sweep record of event-related potential (ERP), the peak latency of P300, which is one of the most prominent positive peaks in the ERP record, might fluctuate according to the recording conditions. The fluctuation of the peak latency (measurement fluctuation) is the summation of the fluctuation caused by physiological factor (physiological fluctuation) and one by noise of background EEG (noise fluctuation). We propsed a method for estimating the interval of the physiological fluctuation based on a limited number of single sweep records. The noise fluctuation was estimated by using the relationship between the signal-to-noise (SN) ratio and the noise fluctuation based on the P300 model and the background EEG model. The interval estimate of the physiological fluctuation were obtained by subtracting the interval estimate of the noise fluctuation from that of the measurement fluctuation. The proposed method was tested by using simulation data of ERP and applied to actual ERP and data of normal subjects, and gave satisfactory results.

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감각처리 장애에 대한 신경생리학적 증거들 (Neurophysiological Evidence for Sensory Processing Disorder)

  • 김은영
    • 재활치료과학
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    • 제1권1호
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    • pp.5-16
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    • 2012
  • 감각통합은 이론에서 출발하여 현재 치료사들이 아동의 문제를 찾고 중재하는데 유용한 틀을 제공한다. 이전까지 대부분의 감각통합 연구들은 감각처리 장애아동들이 나타내는 행동을 측정하는 경험적 증거들을 보고하였다. 최근에 감각처리 장애 진단에 대한 객관적 증거 마련을 위해서 신경생리학적 연구 결과가 축적되기 시작하였다. 감각처리 장애에 대한 신경생리학적 근거를 찾는 연구들은 전기피부 활동, 미주신경 톤, 뇌파를 사용하여 감각처리 장애아동과 전형적으로 발달하는 또래 아동들 간 신경생리학적 반응이 다르다는 결과를 보고하였을 뿐만 아니라 감각처리 어려움과 관련한 행동 특징이 신경생리학적 지표에서도 반영됨을 발견하였다. 앞으로 연구에서는 감각통합 치료 효과를 지지하는 신경생리학적 증거도 얻을 수 있을 것이라 기대해 본다.

1/f 변동리듬 특성을 가지는 음이 쾌적감성에 미치는 영향 (Effect of 1/f Fluctuation Sound on Comfort Sensibility)

  • 전용웅;조암
    • 대한인간공학회지
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    • 제25권4호
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    • pp.9-22
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    • 2006
  • 1/f fluctuation characteristics can be seen in various natural phenomena, such as breezes, streams, candle flames and the luminous patterns of fireflies. It is said that the 1/f fluctuation are comfortable for human beings. And they are introduced into many industrial products, such as an air conditioner, music, lighting, etc. This study focused on verifying the effects of 1/f fluctuation sound on comfort sensibility. Stimulus were divided into three groups(Group 1, 2, 3) by sound generation methodology. Fluctuation patterns of group 1, 2 were given by three types of fluctuation, 1/f0, 1/f1, 1/f2, and its of group 3 were given by two types of pure tone, 1/f1. In order to verify the effects, we measured the physiological responses of the subjects such as EEG(Electroencephalogram), ERP(Event-Related Potential), and these physiological responses were compared with subjective assessments, free answers. Consequently, we found that factor which had an effect on comfort sensibility was cognitive factor(for stimulus) rather than 1/f fluctuation sound pattern.

공동주택 대안적 화재 피난방식에 대한 건설전문가 평가조사 (Analysis on Field Professionals' Assessment of Alternative Fire Escape Methods in Apartment Building)

  • 이명식;이소영
    • KIEAE Journal
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    • 제9권5호
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    • pp.21-28
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    • 2009
  • In apartment buildings, casualties, especially fatalities have occurred in balcony areas in fires if residents fail to escape to the main entrance. Potential consequences of a particular infrequent event should be considered. In attempting to design apartment buildings for fire safety, alternative escape methods such as vertical penetration could be considered. The purpose of this study is to investigate present building regulations regarding apartment buildings and examine pros and cons of the current escape method and alternative escape methods. Focus group interview was conducted to discuss problems of fire escape methods. In addition, questionnaires were distributed to field professionals working in architecture, construction and related industries. Among 500 questionnaires distributed, 192 questionnaires were collected. Usable 162 questionnaires were analyzed using SPSS 15. Regarding alternative fire escape methods, several concerns were mentioned. Safety, privacy, security, effectiveness of escape, water proof problems were raised. Based on the opinions, vertical penetration between apartment unit appeared more safe, secure, effective than horizontal penetration. However, both methods have its own pros and cons under specific contexts. Alternative escape methods need be considered for a selective options for residents in case of fire.