• 한국정보통신학회논문지
• /
• 제12권12호
• /
• pp.2349-2356
• /
• 2008

본 논문에서는 정상인의 정신적인 뇌 활동에 의한 순수한 뇌파를 측정하고 효과적으로 분류하기 위한 방법을 제시한다. 과정은 대상자가 특정한 작업에 대해 생각하게 하고 이때의 뇌파를 청각이벤트에 동기시켜 측정하고, 측정된 뇌파의 기준선의 이동과, 생리적인 아티펙트의 영향을 줄인다. 마지막으로, 평균가산법에 의해 정신적인 작업에 대한 신호만을 추출하고 AR 계수를 가지고 인식작업을 수행한다. 실험에서, 청각자극을 이벤트로 사용하였으며, 뇌파의 도출은 $C_3-A_1$, $C_4-A_2$, $P_Z-A_1$의 3채널에서 기록하였다. 각 채널당 16회의 평균가산후에, 12차 AR계수로 특정한 정신적인 작업에 대한 특징을 추출하였다. 전체 36개의 특징계수를 신경망의 입력으로 사용하고, 각 작업 당 50회를 훈련데이터로 사용하였다. 제안한 방법의 인식률은 2종류 작업에 대해 34-92%, 4종류 작업에 대해 38-54%를 얻었다.

• 대한인간공학회지
• /
• 제23권3호
• /
• pp.89-99
• /
• 2004

A comprehensive psychophysical scaling system, multiple-modality magnitude estimation system (MMES) has been designed to measure subjective multidimensional human perception. Unlike paper-based magnitude estimation systems, the MMES has an additional auditory peripheral cue that varies with corresponding visual magnitude. As the simplest, purely psychological case, bimodal divided-attention conditions were simulated to establish the superiority of the MMES. Subjects were given brief presentations of pairs of simultaneous stimuli consisting of visual line-lengths and auditory white-noise levels. In the visual or auditory focused-attention conditions, only the line-lengths or the noise levels perceived should be reported respectively. On the other hand, in the divided-attention conditions, both the line-lengths and the noise levels should be reported. There were no significant differences among the different attention conditions. Human performance was better when the proportion of magnitude in stimulus pairs were identically presented. The additional auditory cues in the MMES improved the correlations between the magnitude of stimuli and MMES values in the divided-attention conditions.

• 대한의용생체공학회:학술대회논문집
• /
• 대한의용생체공학회 1997년도 춘계학술대회
• /
• pp.370-373
• /
• 1997

We are exposed to the various external stimuli input from the environment, which cause emotional changes based on the characteristics of the stimuli. Unfortunately there are no quantitative results on relationship between human sensibility and the characteristics of physiological signals. The objective of this study was to quantify EEG signals evoked by auditory stimulation based on the assumption that the analysis of the variability on the characteristics of the EEG waveform may provide the significant information regarding changes in psychological states of the subject. The experiment was devised with seven experimental conditions, which are control and six different types of auditory stimulation. Six subjects were used to obtain EEGs while introducing auditory stimulation. Wavelet transformation was employed to analyze the EEG signals. The results showed that the reconstructed signals at the decomposition level revealed the different energy value on the EEG signal. Also, general patterns of EEG signals in rest state compare with negative and positive stimulus were found. This study could be extended to establish an algorithm which distinguishes psychophysiological states of the subjects exposed to the auditory stimulation.

• 대한청각학회지
• /
• 제24권1호
• /
• pp.35-39
• /
• 2020

Background and Objectives: The cortical auditory evoked potential (CAEP) is a useful objective test for diagnosing hearing loss and auditory disorders. Prior to its clinical applications in the pediatric population, the possible influences of fundamental variables on the CAEP should be studied. The aim of the present study was to determine the effects of age and type of stimulus on the CAEP waveforms. Subjects and Methods: Thirty-five healthy Malaysian children aged 4 to 12 years participated in this repeated-measures study. The CAEP waveforms were recorded from each child using a 1 kHz tone burst and the speech syllable /ba/. Latencies and amplitudes of P1, N1, and P2 peaks were analyzed accordingly. Results: Significant negative correlations were found between age and speech-evoked CAEP latency for each peak (p<0.05). However, no significant correlations were found between age and tone-evoked CAEP amplitudes and latencies (p>0.05). The speech syllable /ba/ produced a higher mean P1 amplitude than the 1 kHz tone burst (p=0.001). Conclusions: The CAEP latencies recorded with the speech syllable became shorter with age. While both tone-burst and speech stimuli were appropriate for recording the CAEP, significantly bigger amplitudes were found in speech-evoked CAEP. The preliminary normative CAEP data provided in the present study may be beneficial for clinical and research applications in Malaysian children.

• Journal of Audiology & Otology
• /
• 제24권1호
• /
• pp.35-39
• /
• 2020

Background and Objectives: The cortical auditory evoked potential (CAEP) is a useful objective test for diagnosing hearing loss and auditory disorders. Prior to its clinical applications in the pediatric population, the possible influences of fundamental variables on the CAEP should be studied. The aim of the present study was to determine the effects of age and type of stimulus on the CAEP waveforms. Subjects and Methods: Thirty-five healthy Malaysian children aged 4 to 12 years participated in this repeated-measures study. The CAEP waveforms were recorded from each child using a 1 kHz tone burst and the speech syllable /ba/. Latencies and amplitudes of P1, N1, and P2 peaks were analyzed accordingly. Results: Significant negative correlations were found between age and speech-evoked CAEP latency for each peak (p<0.05). However, no significant correlations were found between age and tone-evoked CAEP amplitudes and latencies (p>0.05). The speech syllable /ba/ produced a higher mean P1 amplitude than the 1 kHz tone burst (p=0.001). Conclusions: The CAEP latencies recorded with the speech syllable became shorter with age. While both tone-burst and speech stimuli were appropriate for recording the CAEP, significantly bigger amplitudes were found in speech-evoked CAEP. The preliminary normative CAEP data provided in the present study may be beneficial for clinical and research applications in Malaysian children.

• 대한의용생체공학회:학술대회논문집
• /
• 대한의용생체공학회 1997년도 춘계학술대회
• /
• pp.176-178
• /
• 1997

We are exposed to the various types of external stimuli, and many researches have been conducted to analyze the emotional changes to the stimuli quantitatively. In this paper, changes of human emotion was studied by analyzing HRV from ECG signals which were varied by the auditory stimulus. Power contents for each frequency bands were calculated from HRV waveforms. Two peak values representing autonomic nervous system status, HF and LF, were used to extract the parameters. An analysis on the normalized HF/LF to the subjective rating of the subject were performed. It was assumed that the positive emotional changes evoked by the auditory stimuli, the HF values representing activation of the parasympathetic nervous system, are increased much higher than the LF values, activation of the sympathetic nervous system. Results showed that the parasympathetic nervous system works more actively than the sympathetic nervous system to the stimuli which cause the positive emotional changes.

• 한국감성과학회:학술대회논문집
• /
• 한국감성과학회 1999년도 춘계학술발표논문집 논문집
• /
• pp.221-230
• /
• 1999

Automobile horn's psychoacoustic characteristic and significance as a anturalistic signal of danger makes it a valuable auditory stimulus to study such psychophysiological responses as startle, orienting and defense reactions. However, comparison and differentiation of physiological responses to commercially available horns is a complicated task due to small contrast of technical features of horns and influence of such processes as habituation on physiological outcome with increased number of auditory stimulation trials. In the study on 10 college students we performed comparative analysis of tonic and phasic reactivity of physiological responses mediated by autonomic nervous system in order to identify role of habituation and decrement of autonomic responsivity, as well as possibility o differentiate subjectively most and least preferred and subjectively more appropriate horns according to physiological manifestations. It was showed that electrodermal and cardiovascular reactivity have concurrent patterns of adaptation to repeated stimulation, namely skin conductance variables habituated, cardiac reactivity failed to show signs of habituation, while vascular component of response were facilitated demonstrating marked sensitization. Differentiation of Physiological responses to horns with respect to their subjective rating scores was possible, however electrodermal reactivity was effective only at the first block of trials, while phasic and tonic cardiovascular reactivity differentiate responses during whole course of experiment. There are discussed possible autonomic mechanisms involved in mediation of observed results.

• 한국임상수의학회지
• /
• 제25권6호
• /
• pp.506-509
• /
• 2008

A 2-month-old, intact female white Bull Terrier presented because of suspected deafness. The coat color was predominantly white and the iris color, of both eyes, was brown. The dog did not respond to the owner's voice when the sound stimuli were presented outside of the visual field; however, the dog responded to visual gestures. The other physical, neurological, otoscopic, radiographic, and blood examinations were unremarkable. To assess the apparent deafness, brainstem auditory evoked responses (BAER) were recorded and analyzed in the dog with suspected deafness as well as a normal littermate. The response in the normal littermate consisted of a series of five wave peaks (I-V) with decreased amplitude and prolonged latency as the stimulus intensity decreased. The BAER from the dog suspected of deafness appeared as a flat line and did not reveal identifiable peaks that corresponded to those found in the normal littermate. Thus, congenital, sensorineural and bilateral deafness was confirmed by the BAER.

• 한국자동차공학회논문집
• /
• 제7권7호
• /
• pp.250-257
• /
• 1999

Driving simulators are used effectively for human factor study, vehicle system development and other purposes by enabling to reproduce actural driving conditions in a safe and tightly controlled enviornment. Interactive simulation requries appropriate sensory and stimulus cuing to the driver . Sensory and stimulus feedback can include visual , auditory, motion, and proprioceptive cues. A fixed-base driving simulator has been developed in this study for vehicle system developmnet and human factor study . The simulator consists of improved and synergistic subsystems (a real-time vehicle simulation system, a visual/audio system and a control force loading system) based on the motion -base simulator, KMU DS-Ⅰ developed for design and evaluation of a full-scale driving simulator and for driver-vehicle interaction.

• 생물정신의학
• /
• 제24권4호
• /
• pp.188-195
• /
• 2017

Objectives Schizophrenia is characterized by disturbances in perception and cognition. Attenuated mismatch negativity (MMN) reflects central auditory dysfunction in schizophrenia. The aim of this study is to compare MMN changes before and after treatment in schizophrenia patients and to assess their association with treatment response. Methods Twenty-three schizophrenia patients underwent an oddball paradigm. MMN was calculated by the difference waveforms of the event-related potentials (ERPs) elicited by subtracting standard from deviant stimulus. The clinical symptoms were measured by the Positive and Negative Syndrome Scale (PANSS), the Psychotic Symptom Rating Scale (PSYRATS). Follow-up evaluation was conducted when the PANSS total score decreased by 30% or more (treatment response group) or before discharge (non-response group). Results The treatment response group showed significantly larger MMN amplitude improvement and latency reduction than the non-response group after treatment (Fz ; mean amplitude p = 0.035, FCz ; p = 0.041). The auditory hallucination group showed shorter latency than that of the group without hallucinations. Additionally, auditory hallucination was associated with prolonged MMN latency and shortened after treatment in the auditory hallucination response group (Fz ; p = 0.048). Conclusions These results suggest that the attenuated MMN amplitude reflects the progression of the disease. The increment of MMN amplitude and shortening of latency after treatment may reflect cognitive functional recovery of central auditory sensory processing.