• Title/Summary/Keyword: Event related potential

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

  • Lee, ByuckJin;Yoo, Sun-Kook
    • Science of Emotion and Sensibility
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    • v.16 no.4
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    • pp.527-534
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    • 2013
  • In this study, we analyzed spatial-frequency relationship related brain function for change of the time during attentional visual stimulus through the analysis of Coherence. With experimentation about ERP(Event Related Potential)data, it revealed that change of the phase synchronization between different scalp locations at ${\theta}$, ${\alpha}$ band. ERP between left and right frontal lobes, between the frontal and central lobes showed the phase synchronization at the P100, N200, ERP between the frontal and occipital lobes showed the phase synchronization at the P300 related information of visual stimulus. Compared to STFT using the window of a fixed length, CWT is able to multi-resolution analysis with the adjustment of parameters of mother wavelet. Thus, coherence results with CWT was found to be effective for analysis of time-varying spatial-frequency relationship in ERP. The phase synchronization for inattentional visual stimulus was not observed.

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

  • 최도성;한효의
    • Journal of Korean Elementary Science Education
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    • v.20 no.1
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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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    • v.33 no.4
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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.

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

  • Lee, Young-Seok
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.10 no.1
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    • pp.9-15
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    • 2017
  • In this study we performed the experiment to detect the ERP using SVM with wavelet features. The EEG signal that is generated visual stimulated ERP database in SCCN applied for the experiment. The feature vectors for experiment are categorized frequency and continuous wavelet- based vectors. In experimental results, the detection rate of SVM with wavelet feature vectors improved above 10% comparing with frequency- based feature vector. Based on the experimental results we analyzed the relation between the activity degree of the ERP and the band split characteristics of the ERP by wavelet transform.

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

  • Kim, Young Youn
    • Proceedings of the Korea Contents Association Conference
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    • 2011.05a
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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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Increased Gamma-band Neural Synchrony by Pleasant and Unpleasant Visual Stimuli (긍정, 부정 감정 유발 시각자극에 의한 감마-대역 신경동기화 증가)

  • Yeo, Donghoon;Choi, Jeong Woo;Kim, Kyung Hwan
    • Journal of Biomedical Engineering Research
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    • v.39 no.2
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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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    • 1994.10a
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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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Neurophysiological Evidence for Sensory Processing Disorder (감각처리 장애에 대한 신경생리학적 증거들)

  • Kim, Eun-Young
    • Therapeutic Science for Rehabilitation
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    • v.1 no.1
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    • pp.5-16
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    • 2012
  • Sensory integration started as a theory to provide a occupational therapist with a useful frame for explaining and intervening the problems which children have. Most researches on sensory processing disorder (SPD) have been found empirical evidence to support the sensory integration theory by measuring behavioral manifestations of SPD. Recently, researchers who are interested in the diagnosis of SPD have begun to use neurophysiological methods to establish objective evidence for sensory integration. These studies reported the neurophysiological indexes reflecting the maladaptive behaviors as well as the difference between children with SPD and typically developing children in using electrodermal activity, vagal tone, EEG. Future neurophysiological studies on SPD will be expected to prove the efficacy of sensory integration intervention.

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

  • Jeon, Yong-Woong;Cho, Am
    • Journal of the Ergonomics Society of Korea
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    • v.25 no.4
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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.

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

  • Lee, Myung Sik;Lee, So Young
    • KIEAE Journal
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    • v.9 no.5
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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.