• Phonetics and Speech Sciences
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• v.9 no.4
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• pp.123-128
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• 2017

This study aims to compare the performance of syllable identification task according to auditory and visual stimuli presentation methods and syllable position. Twenty-two typically developing children (age 4-6) participated in the study. Three-syllable words were used to identify the first syllable and the final syllable in each word with auditory and visual stimuli. For the auditory stimuli presentation, the researcher presented the test word only with oral speech. For the visual stimuli presentation, the test words were presented as a picture, and asked each child to choose appropriate pictures for the task. The results showed that when tasks were presented visually, the performances of phonological awareness were significantly higher than in presenting with auditory stimuli. Also, the performances of the first syllable identification were significantly higher than those of the last syllable identification. When phonological awareness task are presented by auditory stimuli, it is necessary to go through all the steps of the speech production process. Therefore, the phonological awareness performance by auditory stimuli may be low due to the weakness of the other stages in the speech production process. When phonological awareness tasks are presented using visual picture stimuli, it can be performed directly at the phonological representation stage without going through the peripheral auditory processing, phonological recognition, and motor programming. This study suggests that phonological awareness skills can be different depending on the methods of stimulus presentation and syllable position of the tasks. The comparison of performances between visual and auditory stimulus tasks will help identify where children may show weakness and vulnerability in speech production process.

• Sleep Medicine and Psychophysiology
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• v.25 no.1
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• pp.21-26
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• 2018

Objectives: The current study aims to develop Korean Social Affective Visual Stimuli (K-SAVS) to arouse social affect. Methods: K-SAVS is composed of pictures of social situations among East Asians. Each picture contains a negative, positive, or neutral affect. Positive and negative stimuli were presented to one group of subjects. Negative and neutral stimuli were presented to another group of subjects. All subjects were required to fill out Affective Valence and Arousal Manikin. Results: In the initial test, 18 positive affective stimuli pictures (1 set) and 36 negative affective stimuli pictures (2 sets) were chosen from 95 stimuli pictures. Positive affective stimuli pictures showed higher valence (p < 0.001) and lower arousal (p < 0.001) than negative affective stimuli pictures. In the confirmatory test, 18 neutral stimuli pictures (1 set) were additionally selected out of the total of 79 pictures of neutral stimuli pictures and the pictures used in the former experiment. Neutral stimuli pictures showed higher valence (p < 0.001) and lower arousal (p < 0.001) than negative affective stimuli pictures. Conclusion: K-SAVS can be a valid and useful tool for inducing specific social affects of Koreans.

• Proceedings of the ESK Conference
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• 1997.10a
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• pp.468-472
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• 1997

Visual Emotion is attempted to be evaluated by EEG(Electroencephalogram). Twenty university students were participated in this study. IAPS(International Affective Picture System) was used for the visual stimuli. Most positive and most negative emotional response were pairely compared. The results showed alpha increase, delta and beta decrease with postive emotional response, and alpha-delta inter-variation with emotional progress.

• 제어로봇시스템학회:학술대회논문집
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• 1999.10a
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• pp.189-193
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• 1999

For a video data terminal (VDT) operator, visual strain was caused by continuous VDT operations was found id be recovered by watching the picture of virtual far point with the background of the complementary color when the treatment to recover from visual strain was carried out. When the VDT operator watches the picture of virtual far point with the condition of the complementary color stimuli on the CRT display in 60 or 120 minutes after the start of the VDT operation, the visual strain is recovered and the VDT operator is kept healthy.

• Journal of the Ergonomics Society of Korea
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• v.17 no.1
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• pp.67-77
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• 1998

The objective of this study is to extract information from electroencephalogram(EEG) signals with which we can discriminate mental states. Seven university students were participated in this study. Ten stimuli based on IAPS (International Affective Picture Systems) Were presented at random according to the experimental schedule. 8-channel ($O_1$, $O_2$, $F_3$, $F_4$, $F_7$, $F_8$, $FP_1$, and $FP_2$)EEG signals were recorded at a sampling rate of 204.8 Hz for visual stimuli and analyzed. After random ten sequential stimuli presentation, the subject subjectively assessed the stimulus by scaling from -5 to 5. If the stimulus was the best and the worst, it was scored 5 and -5, respectively. Only maximum and minimum scored-EEG signals within each subject were selected on the basis of subjectively assessment for analysis. EEG signals were transformed into feature objects based on scalar autoregressive model coefficients. They were classified with Discriminant Analysis for each channel. The features produced results with the best classification accuracy of 85.7 % in $O_1$ and $O_2$ for visual stimuli. This study could be extended to establish an algorithm which quantify and classify emotions evoked by visual stimulus using autoregressive models.

• Proceedings of the ESK Conference
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• 1997.10a
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• pp.477-481
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• 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 noquantitative results on relationship between human sensibility and the characteristics of physiological signals. The objective of this study was to quantify EEG signals evoked by visual 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. Seven university students were participated in this study. The experiment was devised with eleven experimental conditions, which are control and ten different types of visual stimulation based on IAPS(International Affective Picture Systems). Seven subjects were used to obtain EEGs while introducing visual stimulation. Wavelet transformation was employed to analyze the EEG signals. Most Positive and negative emotional response were pairely compared. The results showed that the reconstructed signals at the decomposition level revealed the different energy value on the EEG signals. Also, general patterns of EEG signals in rest state compare with negative and positive stimulus were found. This study could be extended to estabish an algorithm which distinguishes psychophysiological states of the subjects exposed to the visual stimulation.

• Korean Journal of Biological Psychiatry
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• v.17 no.2
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• pp.79-85
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• 2010

Objectives : Trauma patients have attentional bias which enforces traumatic memories and causes cognitive errors. Understanding of such selective attention may explain many aspects of the posttraumatic stress disorder(PTSD) symptoms. Methods : We used the rapid serial visual presentation(RSVP) method to verify attentional blink in burn patients with PTSD. International affective picture system(IAPS) was used as stimuli and distracters. In the 'neutral test', patients have been presented series of pictures with human face picture as target stimuli. Each picture had 100ms interval. However the distance between target facial pictures was randomized and recognition of second facial picture accuracy was measured. In the 'stress test', the first target was stress picture which arouses patient emotions instead of the facial picture. Neutral and Stress tests were done with seven PTSD patients and 20 controls. In '85ms test' the interval was reduced to 85ms. The accuracy of recognition of second target facial picture was rated in all three tests. Eighty-five ms study was done with eighteen PTSD patients. Results : Attentional blinks were observed in 100-400ms of RSVP. PTSD patients showed increased recognition rate in the 'stress test' compared with the 'neutral test'. When presentation interval was decreased to 85 ms, PTSD patient showed decrease of attentional blink effect when target facial picture interval was 170ms. Conclusion : We found attentional blink effect could be affected by stress stimulus in burn patients. And attentional blink may be affected by stimulus interval and the character of stimulus. There may be some other specific mechanism related with selective attention in attentional blink especially with facial picture processing.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.455-458
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• 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 visual 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. Seven university students were participated in this study. The experiment was devised with eleven experimental conditions, which are control and ten different types of visual stimulation based on IAPS (International Affective Picture Systems). Wavelet transformation was employed to analyze the EEG signals. Most positive and negative emotional response were compared in pairs. The results showed that the reconstructed signals at the decomposition level revealed the different energy value on the EEG signals. Also, general patterns of EEG signals in rest state compare with positive and negative stimulus were found. This study could be extended to establish an algorithm which distinguishes psychophysiological states of the subjects exposed to the visual stimulation.

• Proceedings of the Korean Institute of Landscape Architecture Conference
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• 2007.10b
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• pp.214-219
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• 2007

Psychological and physiological effects of plants were studied by investigating human responses while observing plants. Eighteen healthy adult male(aged between $19{\sim}25$ years) participated in this study. Semantic differential method(SD method) and multi-channel near-infrared spectroscopy(NIRS) were used to survey verbal and non-verbal response, respectively. Cerebral hemodynamics as a new evaluation index of brain activity was recorded for right brain hemisphere where visual information is mainly delivered. Thirty seconds of cerebral blood flow in forty seven channels were calculated when watching five types of picture images with different rates of hedge against gray block wall; 0:10, 3:7, 5:5, 7:3, 10:0. In the SD results, similar evaluations were found in all subjects. However, the change of cerebral hemodynamics as a non-verbal response varied among subjects. Largely two patterns of hemodynamics change were found with increasing plants rate in picture images; group A showed significant decreases of blood flow volume in many cortical regions, Group B had significant increase of blood flow volume in the occipital region for the scenes seen comparatively more plant. Our findings on the cerebral hemodynamics may indicate that there are two patterns of brain activity during observation of plants; group A in which brain areas associated with visual information and thinking work simultaneously to the visual stimuli; group B in which brain areas associated only with visual information work.

• Korean Journal of Cognitive Science
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• v.22 no.4
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• pp.385-404
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• 2011

We examined how emotional background stimuli influence focused attention in a flanker task. An IAPS picture was presented for 1,000ms in advance, then a target and two flanker letters were presented against the IAPS picture for 200ms(Experiment 1). The flanking stimuli were simultaneously presented on the left and right sides of the target stimulus with distance of $0.5^{\circ}C$, $1^{\circ}C$, or $1.5^{\circ}C$ visual angle. We investigated the flanker compatibility effect that identification of target would be faster when they were flanked by identical(compatible) stimuli than when they were flanked by different(incompatible) stimuli. Results of Experiment 1 revealed that the flanker compatibility effect depended not only on the distance of flankers but also on the valence of a background IAPS pictures. Positive and neutral pictures showed distance effect that the flanker compatibility effect was decreased as the farther the distance was, while negative pictures showed no di stance effect. Positive and neutral pictures showed compatibility effects at all distance conditions, but negative pictures didn't showed compatibility effect at $1.5^{\circ}C$ distance condition. In Experiment 2, the SOA(Stimulus Onset Asynchrony) between the picture and the stimuli of flanker task was manipulated. The flanking stimuli were presented simultaneously on the left and right sides of the target stimulus with a distance of either $0.5^{\circ}C$ or $1.5^{\circ}C$ visual angle. The results of Experiment 2 showed that flanker compatibility effect depends on SOA. At long SOA(2800ms), negative pictures showed no distance effect, but positive or neutral pictures did. All valence conditions of background pictures showed compatibility effects at $0.5^{\circ}C$ distance condition, but didn't showed compatibility effect at $1.5^{\circ}C$ distance condition. At short SOA(100ms), all valence conditions of background pictures showed distance effect, and showed compatibility effects with the exception of negative background pictures at $1.5^{\circ}C$ distance condition. These findings suggest that the scope of visual attention becomes narrower when viewing negative emotional stimuli and becomes broadened when viewing positive emotional stimuli. The narrowed scope of attention in negative emotion lasts longer, while the broaden scope of attention in positive emotion lasts shorter.