• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• 제22권4호
• /
• pp.211-218
• /
• 2011

Objectives : Intellectual impairment in children with attention-deficit hyperactivity disorder (ADHD) is often associated with relatively severe cognitive dysfunction. This study was designed to investigate cognitive function using auditory and visual event-related potential P300 in children with ADHD with relatively higher and lower IQ. Methods : A total of 20 children aged 6-12 years with DSM-IV-TR diagnosis of ADHD-combined type were recruited. For 10 children with lower IQ (${\leq}$100) and 10 children with higher IQ (>100), auditory and visual P300 using oddball paradigm (target 0.2, standard 0.8, in probability) were employed. Results : No significant differences were found in P300 amplitude and latency between ADHD children with higher and lower IQ in both modalities. However, auditory P300 amplitude in the right parietal area (P8 electrode) was negatively correlated with verbal IQ in ADHD subjects (R=-.50, p<.05). Visual P300 amplitude in the left parietal area (P3 electrode) was positively correlated with performance IQ in ADHD subjects (R=.57, p<.01). Conclusion : This study suggests intellectual impairment, as evidenced by lower IQ, could not be associated with cognitive dysfunction reflected in event-related potential P300 in ADHD children. However, cognitive function reflected in intellectual subcomponents and P300 might be processed in a stimulus modality-specific and asymmetric pattern.

• 방송공학회논문지
• /
• 제27권5호
• /
• pp.738-750
• /
• 2022

본 논문은 XR 콘텐츠나 인터페이스 환경에서 활용할 수 있는 음향 자극의 종류를 고찰하고, 청각 자극 기반의 감성 유발이 뇌과학적으로 실효성을 가지는지에 대해 논의하였다. 외부 청각자극, 감성변화 및 뇌연결성의 상관관계 규명에 초점을 맞추어, XR 환경에서 사용자 경험을 제고하기 위한 기계학습 기반 개인 맞춤형 사운드 트랙 제공 서비스 개발이 필요하다는 시사점을 도출하였다. 또한, 짧은 음향자극으로 감성을 유발할 수 있는지를 테스트하여 청각자극에 의해 유발된 각성상태에서 우측 전두엽이나 전두엽, 두정엽, 후두엽 네트워크에서 뇌의 기능적 연결성이 강화되고 이완시에는 상반된 패턴을 보이는 것을 확인하였다. 본 연구에서 도출된 결과는 보다 입체적인 XR 상호작용 경험을 제시하고 사용자의 XR 인지수용성을 제고하여, 현장에서 실질적으로 적용될 수 있는 초실감 XR 사운드 바이오피드백 시스템 개발에 활용될 수 있을 것이다.

• Annals of Clinical Neurophysiology
• /
• 제12권2호
• /
• pp.35-46
• /
• 2010

Various electrophysiological tests have provided a large body of valuable information on neuronal responses to a presented stimulus. The special and general somatic sensory pathways are main targets of evoked potentials. Two types of evoked potentials, exogenous and endogenous, are commonly used. Exogenous evoked potentials of general and special somatic sensory systems will be reviewed. One of general somatic sensory functional pathways, proprioception, can be evaluated by general somatosensory evoked potentials with electrical stimulation on nerves. The special somatosensory functional pathways, including vision, and audition, can be evaluated by visual evoked potentials and auditory evoked potentials. Also laser-evoked potentials are newly developed for pain pathway, including lateral spinothalamic pathway, and vestibular myogenic evoked potentials for sacculocollic pathways. The evoked potentials of sensory system have maximal clinical utility in evaluating functional deficits along the sensory pathways. They are used for evaluating comatose patients, hysterical patients, premature infants, patients with suspected demyelinating diseases or neoplasms, and research. We discuss the neurophysiologic tests of sensory systems in views of practical points. The organized evaluation of sensory electrophysiologic tests can be helpful in detecting and estimating the abnormalities in neurological diseases.

• 한국감성과학회:학술대회논문집
• /
• 한국감성과학회 2003년도 춘계학술대회 논문집
• /
• pp.84-89
• /
• 2003

The virtual reality(VR) technology can provide various stimuli, including, visual and auditory stimuli, simultaneously in the virtual environment and encourage the user to interact. Virtual reality is a set of computer technologies, which when combined, provide an interactive interface to a computer generated world. In this world the subject can see, hear and navigate in a dynamically changing environment in which he participates as an active player, by modifying the environment according to his will. Moreover, the subject can get a feeling for the virtual environment in much the same way as one feels real life situations. In the real world, a plethora of information from various modalities may be in conflict, and modulate each other to form an illusion. In this study we investigated whether a tactile illusion on a real hand could be evoked by a virtual stimulus, the time required to generate this illusion and its duration. This study shows that the illusion occurred, and that was correlated with presence score in the virtual environment.

• 대한청각학회지
• /
• 제24권2호
• /
• pp.71-78
• /
• 2020

Background and Objectives: Currently limited information is available on speech stimuli processing at the subcortical level in the recipients of cochlear implant (CI). Speech processing in the brainstem level is measured using speech-auditory brainstem response (S-ABR). The purpose of the present study was to measure the S-ABR components in the sound-field presentation in CI recipients, and compare with normal hearing (NH) children. Subjects and Methods: In this descriptive-analytical study, participants were divided in two groups: patients with CIs; and NH group. The CI group consisted of 20 prelingual hearing impairment children (mean age=8.90±0.79 years), with ipsilateral CIs (right side). The control group consisted of 20 healthy NH children, with comparable age and sex distribution. The S-ABR was evoked by the 40-ms synthesized /da/ syllable stimulus that was indicated in the sound-field presentation. Results: Sound-field S-ABR measured in the CI recipients indicated statistically significant delayed latencies, than in the NH group. In addition, these results demonstrated that the frequency following response peak amplitude was significantly higher in CI recipients, than in the NH counterparts (p<0.05). Finally, the neural phase locking were significantly lower in CI recipients (p<0.05). Conclusions: The findings of sound-field S-ABR demonstrated that CI recipients have neural encoding deficits in temporal and spectral domains at the brainstem level; therefore, the sound-field S-ABR can be considered an efficient clinical procedure to assess the speech process in CI recipients.

• Journal of Audiology & Otology
• /
• 제24권2호
• /
• pp.71-78
• /
• 2020

Background and Objectives: Currently limited information is available on speech stimuli processing at the subcortical level in the recipients of cochlear implant (CI). Speech processing in the brainstem level is measured using speech-auditory brainstem response (S-ABR). The purpose of the present study was to measure the S-ABR components in the sound-field presentation in CI recipients, and compare with normal hearing (NH) children. Subjects and Methods: In this descriptive-analytical study, participants were divided in two groups: patients with CIs; and NH group. The CI group consisted of 20 prelingual hearing impairment children (mean age=8.90±0.79 years), with ipsilateral CIs (right side). The control group consisted of 20 healthy NH children, with comparable age and sex distribution. The S-ABR was evoked by the 40-ms synthesized /da/ syllable stimulus that was indicated in the sound-field presentation. Results: Sound-field S-ABR measured in the CI recipients indicated statistically significant delayed latencies, than in the NH group. In addition, these results demonstrated that the frequency following response peak amplitude was significantly higher in CI recipients, than in the NH counterparts (p<0.05). Finally, the neural phase locking were significantly lower in CI recipients (p<0.05). Conclusions: The findings of sound-field S-ABR demonstrated that CI recipients have neural encoding deficits in temporal and spectral domains at the brainstem level; therefore, the sound-field S-ABR can be considered an efficient clinical procedure to assess the speech process in CI recipients.

• Journal of Audiology & Otology
• /
• 제23권1호
• /
• pp.39-48
• /
• 2019

Background and Objectives: The influence of visual stimulus on the auditory component in the perception of auditory-visual (AV) consonant-vowel syllables has been demonstrated in different languages. Inherent properties of unimodal stimuli are known to modulate AV integration. The present study investigated how the amount of McGurk effect (an outcome of AV integration) varies across three different consonant combinations in Kannada language. The importance of unimodal syllable identification on the amount of McGurk effect was also seen. Subjects and Methods: Twenty-eight individuals performed an AV identification task with ba/ga, pa/ka and ma/ṇa consonant combinations in AV congruent, AV incongruent (McGurk combination), audio alone and visual alone condition. Cluster analysis was performed using the identification scores for the incongruent stimuli, to classify the individuals into two groups; one with high and the other with low McGurk scores. The differences in the audio alone and visual alone scores between these groups were compared. Results: The results showed significantly higher McGurk scores for ma/ṇa compared to ba/ga and pa/ka combinations in both high and low McGurk score groups. No significant difference was noted between ba/ga and pa/ka combinations in either group. Identification of /ṇa/ presented in the visual alone condition correlated negatively with the higher McGurk scores. Conclusions: The results suggest that the final percept following the AV integration is not exclusively explained by the unimodal identification of the syllables. But there are other factors which may also contribute to making inferences about the final percept.

• 대한청각학회지
• /
• 제23권1호
• /
• pp.39-48
• /
• 2019

Background and Objectives: The influence of visual stimulus on the auditory component in the perception of auditory-visual (AV) consonant-vowel syllables has been demonstrated in different languages. Inherent properties of unimodal stimuli are known to modulate AV integration. The present study investigated how the amount of McGurk effect (an outcome of AV integration) varies across three different consonant combinations in Kannada language. The importance of unimodal syllable identification on the amount of McGurk effect was also seen. Subjects and Methods: Twenty-eight individuals performed an AV identification task with ba/ga, pa/ka and ma/ṇa consonant combinations in AV congruent, AV incongruent (McGurk combination), audio alone and visual alone condition. Cluster analysis was performed using the identification scores for the incongruent stimuli, to classify the individuals into two groups; one with high and the other with low McGurk scores. The differences in the audio alone and visual alone scores between these groups were compared. Results: The results showed significantly higher McGurk scores for ma/ṇa compared to ba/ga and pa/ka combinations in both high and low McGurk score groups. No significant difference was noted between ba/ga and pa/ka combinations in either group. Identification of /ṇa/ presented in the visual alone condition correlated negatively with the higher McGurk scores. Conclusions: The results suggest that the final percept following the AV integration is not exclusively explained by the unimodal identification of the syllables. But there are other factors which may also contribute to making inferences about the final percept.

• 대한의용생체공학회:학술대회논문집
• /
• 대한의용생체공학회 1994년도 춘계학술대회
• /
• pp.69-71
• /
• 1994

1Hz에서 20Hz까지의 단속 주파수를 지닌 청각자극을 가해 얻은 EEG신호에서 자극에 따른 신호의 정성적이고 정량적인 특성을 카오스 분석방법을 통해 밝혔다. 먼저, 뇌전위 신호에 전반적으로 나타나는 일반적인 카오스 특징(fractal mechanism, 1/f frequency spectrum, positive lyapunov exponent등등)이 확인되어졌다. 유발전위에 대해서는 자극의 주파수에 따른 주기 배증을 경유한 카오스로 가는 길(route to chaos)과 2차원 pseudo-phase portrait의 뿌앙까레 단면에서의 기하학적 모양(topological property)의 변화가 관찰되어졌고, 자발전위가 포함된 유발전위에 대해서는 적절한 bases를 지닌 3차원 phase space에서 기이한 끌개(chaotic attractor)가, 유발전위의 정보를 지닌채 보여졌다. 끝으로 자극 주파수(단속 주파수와 반송 주파수) 변화와 측정이 이루어진 머리표면에서의 공간적 위치에 따른, lyapunov exponent값 변화가 의미있게 해석되어졌다. 이 결과는 무질서하게 보이는 뇌전위신호에서 주어진 청각자극에 대한 정보를 얻는 새로운 방법을 제시하게 된다.

• 한국지능시스템학회논문지
• /
• 제10권4호
• /
• pp.304-309
• /
• 2000

인간의 뇌 정보처리를 이해하기 위한 일환으로서, 많은 연구자들이 사람의 두피에서 자발적으로 발생하는 전기 활동인 뇌파(EEG)를 분석하였다. 측정된 뇌파는 잠음처럼 보이는 비선형적인 거동으로 인하여 단순한 관찰만으로 그 특징을 분석하기가 매우 어렵다. 따라서 이러한 뇌파를 분석하고 이해하기 위한 방법으로 파워스펙트럼, 바이스펙트럼 등과 같은 스펙트럼 분석과 상관차원, 프랙탈 차원과 같은 비선형 카오스 분석 등과 같은 해석법들이 활발히 연구되어왔다. 본 논문에서는 이러한 기존의 방법 외에 두 신호사이의 통계적 의존성을 측정하는 양인 상호정보를 이용하여 뇌파의 특징을 분석하였다. 뇌파간의 상호정보 분석을 통해 두뇌에서의 정보의 흐름에 관한 특징을 알아보았고, 감선자극에 반응하는 두뇌의 활동영역을 알 수 있었다.