• Annals of Clinical Neurophysiology
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• 제23권2호
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• pp.69-81
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• 2021

Cortico-cortical evoked potential (CCEP) mapping is a rapidly developing method for visualizing the brain network and estimating cortical excitability. The CCEP comprises the early N1 component the occurs at 10-30 ms poststimulation, indicating anatomic connectivity, and the late N2 component that appears at < 200 ms poststimulation, suggesting long-lasting effective connectivity. A later component at 200-1,000 ms poststimulation can also appear as a delayed response in some studied areas. Such delayed responses occur in areas with changed excitability, such as an epileptogenic zone. CCEP mapping has been used to examine the brain connections causally in functional systems such as the language, auditory, and visual systems as well as in anatomic regions including the frontoparietal neocortices and hippocampal limbic areas. Task-based CCEPs can be used to measure behavior. In addition to evaluations of the brain connectome, single-pulse electrical stimulation (SPES) can reflect cortical excitability, and so it could be used to predict a seizure onset zone. CCEP brain mapping and SPES investigations could be applied both extraoperatively and intraoperatively. These underused electrophysiologic tools in basic and clinical neuroscience might be powerful methods for providing insight into measures of brain connectivity and dynamics. Analyses of CCEPs might enable us to identify causal relationships between brain areas during cortical processing, and to develop a new paradigm of effective therapeutic neuromodulation in the future.

• Clinical and Experimental Pediatrics
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• 제50권1호
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• pp.7-13
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• 2007

Hearing loss in newborns is the most frequently occurring birth defect. If hearing impaired children are not identified and managed early, it is difficult for many of them to acquire the fundamental language, social and cognitive skills that provide the foundation for later schooling and success in society. All newborns, both high and low risk, should be screened for hearing loss in the birth hospital prior discharge (Universal Newborn Heaing Screening, UNHS). Objective physiologic measures must be used to detect newborns and very young infants with hearing loss. Recent technological developments have produced screening methods and both evoked otoacoustic emission (EOAE) and auditory brainstem response (ABR) have been successfully implemented for UNHS. Audiologic evaluation should be carried out before 3 months of age and infants with confirmed hearing loss should receive intervention before 6 months of age. All infants who pass newborn hearing screening but who have risk indicators for other auditory disorders and/or speech and language delay receive ongoing audiologic surveillance and monitoring for communication development. Infants with sensorineural hearing loss are managed with hearing aids and receive auditory and speech-language rehabilitation therapies. Cochlear implants can be an outstanding option for certain children aged 12 months and older with severe to profound hearing loss who show limited benefit from conventional amplifications.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.623-627
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• 2007

In case of the Grand Performance Hall, in view of its distinctiveness, since various Assembly Activity as well as Lecture together with the use for Music are important besides the purpose of Performance itself, the consideration with regard to the sound environment which enables to minimize the acoustic defect has appeared on the stage as an essential factor. On this viewpoint, this Study has attempted to examine the acoustic satisfaction degree and its response regarding to the grand performance hall by means of the measurement and valuation about the psychological volume of human-being using the auditory-evoked technology that possible to experience the Virtual Sound Field at the designing stage, after practice of the optimized acoustic design for the object of the grand performance hall on the step of construction. As the result of auditory-evocation, it was known that the valuation about the acoustic performance after reformation has been improved affirmatively than before reformation. It is considered that such outcome of the study could be utilized as the useful material that enables to improve the curtailment effect of construction cost and the acoustic performance, by means of the presupposition control about the acoustic problem from the stage of design, for the occasion when the similar Performance Hall is planning to build, hereafter.

• 한국음향학회지
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• 제35권1호
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• pp.63-73
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• 2016

청각기관의 음조체계로 인해 사람들은 일반적으로 주파수 분포에 따라 소리를 듣는다. 그러나 어음인지 측면에서 어음의 음향적 특성이 사람의 뇌에서 어떻게 인식되는지는 여전히 명확하지 않다. 따라서 본 연구에서는 유사한 고주파수 음향적 특성을 갖는 두 개의 어음이 청각 뇌간에서 전기생리학적으로 어떻게 발현되는 지 확인하고자 하였다. 정상 청력을 지닌 20대 성인 33명이 실험에 참여하였다. 자극음으로 두 개의 한국어 단음절 /자/와 /차/, 4개의 주파수로 구성된 톤버스트음(500, 1000, 2000, 4000 Hz)을 사용하여 청성뇌간반응을 얻었다. 연구 결과, 단음절과 톤버스트음 모두 높은 재현성을 보였고, 파형 V는 모든 피검자에게서 잘 발현되었다. 피어슨 상관관계 분석 결과, 3671 ~ 5384 Hz 대역에서 에너지 분포를 갖는 /자/ 음절은 4000 Hz의 톤버스트음과 높은 상관관계를 나타냈다. 그러나 /차/ 음절은 1000 Hz와 2000 Hz의 톤버스트음과 높은 상관성을 보여, 3362~5412 Hz의 음향적 특성과 청각 뇌간에서 생리학적 반응은 일치하지 않았다. 이러한 결과를 바탕으로 사람의 어음인지과정을 면밀히 조사하기 위해 음향-청지각적 매핑후속 연구가 필요하겠다.

• 전자공학회논문지
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• 제50권6호
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• pp.287-293
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• 2013

인공와우는 유모세포의 손실로 청신격 자극이 되지 않을 경우, 삽입된 전극에 전기자극을 가함으로써 청감각을 회복하는 장치이다. 인공와우의 성능을 향상하기 위하여, 자극에 따른 정확한 신경반응을 이해하는 것이 매우 중요하고, 임상에서는 electrically evoked compound action potential (ECAP)을 측정하여 신경반응을 측정하고 있다. 본 연구에서는 실제 달팽이관과 유사한 3차원 달팽이관 유한요소 모델을 개발하고, 자극에 따른 신경반응을 측정할 수 있는 ECAP 알고리즘을 개발하였다. 개발된 3차원 달팽이관 모델을 이용하여, 전기 자극에 따른 ECAP 크기와 반응 잠복 시간을 측정하였으며, 측정된 결과 임상시험과 동물실험에서 측정된 ECAP 크기와 반응 잠복 시간과 유사한 값을 얻을 수 있었다. 본 3차원 달팽이관 모델은 전기 자극에 대한 신경 반응을 분석함으로써 인공 와우의 성능을 향상시키기 위한 전기자극 방식을 연구하는데 유용하게 이용될 수 있다.

• 수면정신생리
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• 제1권1호
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• pp.87-98
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• 1994

연구배경 : 정신분열증 환자들이 정보처리 과정의 문제가 있을 것이라는 가설을 지지해 주는 사건관련유발 전위인 P3의 이상을 보고하는 연구들이 있어 저자들은 정신분열증 환자들에게 청각사건관련유발 전위를 실시하여 P3의 이상을 확인하고자 하였다. 또한, 음성 및 양성 정신분열증환자에 P3의 차이가 있는지 비교하였으며, 가족력이나 전기충격경련요법, 밖에 임상양상과 P3와의 연관성을 알아보기 위하여 본 연구를 실시하였다. 방법 : DSM-III-R 진단기준에 맞는 정신분열증 환자 54명 (남자 31, 여자 23) 과 그 대조군 75 명 (남자 33, 여자 42) 을 대상으로 oddball paradigm 을 이용한 사건관련유발전위를 실시하여 P3의 잠복기와 진폭을 측정하였으며, 정신분열증의 인지기능이상을 알아볼 수 있는 프랑크푸르트 임상검사를 같이 실시하였다. 결과 : 정신분열증 환자의 P3 잠복기는 그 대조군에 비해 의미 있게 지연되어 있었으며, 또한 모든 진폭도 대조군에 비해 의미 있게 감소되어 있었다. 정신분열증 환자군에서 프랑크푸르트 임상검사의 10가지 임상증상 모두에서 통계적으로 유의하게 높은 점수를 보였다. PANSS의 종합점수에 따라 음성과 양성으로 나누어 비교한 결과, P3의 잠복기 및 진폭에서 의미 있는 차이가 발견되지 않았다. 또한, 정신과질환의 가족력의 유무에 따라, 전기 충격경련요법 유무에 따라 비교한 결과 의미 있는 차이를 발견할 수 없었다. 환자군에서 프랑크푸르트 임상검사의 임상증상, 그밖에 임상특성과 P3의 잠복기와 진폭 사이에 연관성을 발견할 수 없었다. 결론 : 본 연구의 결과로 정신분열증 환자들에서 선택적 주의집중 과정의 이상이 있을 것이고 추측할 수 있었으며, 임상양상이나 가족력 유무와 P3사이에 연관성이 없다는 것을 시사해 주었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 심포지엄 논문집 정보 및 제어부문
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• pp.141-142
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• 2008

Hearing loss is the most common birth defect among infants. Yet most hearing-impaired children are not identified until 1 to 3 years of age - which is well beyond the critical period(6 month) for healthy speech and language development. However, if a hearing-impairment is identified and treated in its early stages, child's speech and language skills will be comparable to his or her normal- hearing peers. For these reasons, hearing screening at birth and routinely throughout childhood is extremely important. Auditory brain-stem response(ABR) is nowadays one of the most reliable diagnostic tools in the early detection of hard of hearing. In this study, we developed the system that detects auditory evoked potential using micro-processor. Furthermore, it is required to develop a portable system to measure in not only soundproof room but also nursery for infants.

• 대한전기학회논문지:시스템및제어부문D
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• 제49권6호
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• pp.334-338
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• 2000

Even though it is not practical, yet there is a trend of the researches related to the anesthesia on the determination of depth of anesthesia and level of consciousness in the view point of neurophysiological aspects. That is, quantification of physiological signals which represent human brain function and pharmacological response could be used to find the level of consciousness based on the changes in physiological signals. This research was performed to analyze the relationship between parameters extracted from LAEP(long latency auditory evoked potential) and the amount of sedatives injected to the patients. Seventeen patients were participated for the experiment. Two different sedatives, midazolam and diazepam, were injected intramuscularly, and LAEPs caused by 1KHz and 2KHz auditory tone bust were obtained. It was found that amplitude of extracted parameters from LAEP, N100 and P300, were reduced as dose of sedatives were increased. Results of this study could be used for extracting more meaningful index and establishing algorithm for predicting changes of level of consciousness induced by sedatives.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 1997년도 한국감성과학회 연차학술대회논문집
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• pp.228-232
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• 1997

The special interest should be paid to the analysis of the influences of positive emotions in terms of their possible effects on the dyanmics of autonomic. recovery after the negative affective stimualtion. Taking into account emotion-specific autonomic response patterning and dissociation of parameters of autonomic arousal during experience of both positive and negative emotional states, this problem seems a challenging one. In present study several autonomic parameters were analyzed altogether, namely inedices of electrodermal activity, heart rate and respitation rate during consecutive combination or both IAPS-based visual affective and auditory stimulation. The aim of the study was analysis of patterns of electrodermal and cardiorespiratory responses during emotional states evoked by negative affective visual stimulation followed by positive or neutral auditory one with intention to identify if the latter is able to facilitate post-stress recovery and enhance restoration of pre-arousal levels. The main orientation was dirdcted towards the further application of experimentally induced comfort emotions for dampening the negative consequences of exposure to stressful stimuli.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1999년도 학술발표대회 논문집 제18권 1호
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• pp.269-273
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• 1999

Combination of mental stress task with noise background is a traditional tool employed in psychophysiology. However, intensity of background noise is a factor affecting both performance on test and psychophysiological responses associated with stress evoked by mental load in noisy environment. In the current study on 7 subjects we analyzed the influence of white noise (WN) intensity (55, 70, and 85 dB[A] ) on psychophysiological responses during word recognition test performed on noise background. There were recorded following physiological variables: electrodermal activity (EDA) , namely, skin conductance level (SCL), skin conductance response (SCR) amplitude (SCR-A), rise time and total number of SCRs (N-SCR); cardiovascular activity, e.g., heart rate (HR), respiratory sinus arrhythmia (RSA) index, pulse transit time (PTT), finger pulse volume (PV), skin temperature (SKT) and respiratory activity, such as respiration rate (RESP-R) and inspiration wane amplitude (RESP-A) during baseline resting state and 40 s long performance on 3 similar Korean word recognition tests with different WN intensity (55, 70, and 85 dB). Electrodermal responses (SCR-A, SCL, N-SCR) demonstrated gradual increment with increased intensity of noise, and this increase of response magnitude with higher intensity of noise was typical also for r skin temperature (phasic SKT decrease) and pulse volume (phasic and tonic PV decrease). However, some cardiovascular and respiratory responses did not exhibit same tendency of gradual increase of reactivity , namely HR, as well as RESP-R and RESP-A showed decrement of response magnitudes. Important finding in terms of cardiovascular reactivity was that 55 and 70dB evoked similar profiles, while 85dB WN resulted in significantly different profile of reactions, suggesting that there exists a threshold level after which intensive auditory stimulation elicits psychophyslological responses pattern of different quality. There are discussed potential autonomic mechanism involved in mediation of observed physiological responses.