• Korean Journal of Cognitive Science
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• v.27 no.2
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• pp.275-301
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• 2016

Attentional blink (AB) refers to the phenomena where conscious report for a target (T2) subsequent to the first target (T1) in a stream of items under rapid serial visual presentation (RSVP) becomes difficult if the T2 follows no later than 500ms after the T1. The present study examined the effect of T1 visibility on T2 AB strength according to the bottleneck account proposing that the amount of allocated resources for T1 memory consolidation determines the strength of AB against T2. In the low-visibility condition, the T1 had a gray color for a low stimulus contrast against the black background whereas had a bright and saturated color in the high-visibility condition. In both visibility conditions, the T1 was also highly distinct from the remaining distractors. A multi-RSVP method was also used for increasing location uncertainty of the targets supposedly consuming on average attentional resources for the targets. Two experiments revealed that AB strength was more intense in the low-visibility than high-visibility condition, and the pattern of difference went more pronounced if T2 visibility was improved. The results indicate that T1 visibility can affect more strongly when attentional resources are relatively lacking for resolving the T1 bottleneck, and support for the bottleneck account proposing that the level of T1's visibility can determine the intensity of the T1 bottleneck.

• Korean Journal of Cognitive Science
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• v.29 no.1
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• pp.39-59
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• 2018

To elucidate the effect of working memory (WM) load on negative facial emotion processing, we examined ERP components (P1 and N170) elicited by fearful and neutral expressions each of which was presented during 0-back (low-WM load) or 2-back (high-WM load) tasks. During N-back tasks, visual objects were presented one by one as targets and each of facial expressions was presented as a passively observed stimulus during intervals between targets. Behavioral results showed more accurate and fast responses at low-WM load condition compared to high-WM load condition. Analysis of mean amplitudes of P1 on the occipital region showed significant WM load effect (high-WM load > low-WM load) but showed nonsignificant facial emotion effect. Analysis of mean amplitudes of N170 on the posterior occipito-temporal region showed significant overall facial emotion effect (fearful > neutral), but, in detail, significant facial emotion effect was observed only at low-WM load condition on the left hemisphere, but was observed at high-WM load condition as well as low-WM load condition on the right hemisphere. To summarize, facial emotion effect observed by N170 amplitudes was modulated by WM load only on the left hemisphere. These results show that early emotional processing of negative facial expression could be eliminated or reduced by high load of WM on the left hemisphere, but could not be eliminated by high load on the right hemisphere, and suggest right hemispheric lateralization of negative facial emotion processing.

• Science of Emotion and Sensibility
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• v.14 no.3
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• pp.371-384
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• 2011

Three experiments were carried out to examine how LED lighting hues influence to the rating and recognition of affective stimuli. In Experiment 1 and 2, IAPS affective pictures were used and an affective rating(valence and arousal) task and a recognition memory task were conducted under red, green, blue, and white hue LED lightings in Experiment 1 and cyan, magenta, yellow, and white ones in Experiment 2, respectively. In Experiment 3, affective words were used and the same two tasks were conducted under red, green, blue, and white hue LED lightings. According to the results of affective rating tasks, when primary hues(RGB) were used, red LED lighting elicited an excitement at the arousal dimension and green LED lighting evoked pleasantness at the valence one. When secondary hues(CMY) were used, magenta and cyan showed the similar but weaker patterns of responses comparing to red and green. The results of recognition memory task showed that the responses to the picture stimuli presented at green and cyan hue lightings tended to be a bit faster comparing to the stimuli presented at the other conditions but the difference was insignificant. In Experiment 3, however, recognition memory responses to the affective words presented at green hue lighting were faster significantly. These results indicate that warm colors like red and magenta elicit unpleasantness or excitement while cool colors like green and cyan evoke pleasantness or relaxation, and the primary hues provoke more positive or negative affectivity than secondary ones do. Particularly, the result of recognition memory task in Experiment 3 suggests that green hue LED lighting might be advantageous at the memory performance of language stimuli rather than visual ones.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.2
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• pp.689-695
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• 2010

The effect of the code conversion process of Korean script (Hangul), also known as words for numbers, was investigated using event-related potentials (ERPs) during mental arithmetic operations. Study subjects were asked to determine whether the arithmetic results of a given target stimuli were correctly matched. Visual inspection and statistics of mean ERPs showed stimulus type-dependent processing rather than task-dependent processing. Results of addition and multiplication tasks revealed that the overall temporal profiles of the Arabic numerals were similar to the Hangul words for numbers. The only exception to this observation was a delayed positive-slope peak occurring around 300 ms, which was likely related to the encoding process of Hangul words for numbers to Arabic-digits, defined as a 'transcoding-related potential.' Source analysis confirmed that the topography of different waveforms for the two conditions was attributed to a single dipole located in the left temporo-parietal area; this area is known to be involved in Hangul words for number processing. These results suggest that the initial processing for encoding words for numbers was followed by arithmetic operations without direct access of internal number representation. Korea Academia-Industrial cooperation Society. The Korea Academia-Industrial cooperation Society. The Korea Academia-Industrial cooperation Society. The Korea Academia-Industrial cooperation Society.

• Journal of KIISE:Software and Applications
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• v.29 no.11
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• pp.837-850
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• 2002

In this paper, we propose an EEG-based response time prediction method during a yes/no cognitive decision task. In the experimental task, a subject goes through responding of visual stimulus, understanding the given problem, controlling hand motions, and hitting a key. Considering the subject's varying brain activities, we model subjects' mental states with defining CT (cut time), ST (selection time), and RP (repeated period). Based on the assumption between ST and RT in the mental model, we predict subjects' response time by detection of selection time. To recognize the subjects' selection time ST, we extract 3 types of feature from the filtered brain waves at frequency bands of $\alpha$, $\beta$, ${\gamma}$ waves in 4 electrode pairs combined by spatial relationships. From the extracted features, we construct specific rules for each subject and meta rules including common factors in all subjects. Applying the ST detection rules to 8 subjects gives 83% success rates and also shows that the subjects will hit a key in 0.73 seconds after ST detected. To validate the detection rules and parameters, we test the rules for 2 subjects among 8 and discuss about the experimental results. We expect that the proposed detection method can be a basic technology for brain-computer-interface by combining with left/right hand movement or yes/no discrimination methods.

• Journal of Science of Art and Design
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• v.12
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• pp.5-41
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• 2007

As public attention on Well-being culture increases, it is now considered to be a new trend of modern society. The purpose of this study is to publicize the necessity of design products which are advanced in quality and encourage the use of it. The researcher judged that study on design of lighting product to adopt well-being trend is in preliminary level and aims to research on the tendency of well-bing trend and lighting design which the consumer of this age is demanding. As the result of changes in modern consumption trend, design is considered to be a factor of capricious cultural phenomenon. In addition to this, as high technology such as ubiquitous develops with the degitalisation and informatization, the consumer are paying attention to dynamic products rather than static products or products which respond to external stimulus. Products which adopt well-being trend pursuing nature friendly life are particularly preferred It means that not only the basic function of products but also design which satisfy the five sense is required. Modern consumers use products in various way. However, the pro-environmental and human-centered tendency is tried only in very limited area and general study on this matter is extremely rare. This study analyzes the factors which intercepts the adoption of well-being trend to lighting products and seeks for an alternative to solve the problem. Interaction design with well-being trend was adopted to lighting design and the result presented that there is a possibility to differentiate existing lighting design by adding interaction design to the existing lighting design. Therefore, the need for further study on this matter is presented.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.3
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• pp.115-122
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• 2016

This paper proposes a system to detect driver's cognitive state by internal and external information of vehicle. The proposed system can measure driver's eye gaze. This is done by concept of information delivery and mutual information measure. For this study, we set up two web-cameras at vehicles to obtain visual information of the driver and front of the vehicle. We propose Gestalt principle based selective attention model to define information quantity of road scene. The saliency map based on gestalt principle is prominently represented by stimulus such as traffic signals. The proposed system assumes driver's cognitive resource allocation on the front scene by gaze analysis and head pose direction information. Then we use several feature algorithms for detecting driver's characteristics in real time. Modified census transform (MCT) based Adaboost is used to detect driver's face and its component whereas POSIT algorithms are used for eye detection and 3D head pose estimation. Experimental results show that the proposed system works well in real environment and confirm its usability.

• Progress in Medical Physics
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• v.16 no.3
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• pp.148-154
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• 2005

Since the output of retina for visual stimulus is carried by neurons of very diverse functional properties, it is not adequate to use conventional single electrode for recording the retinal action potential. For this purpose, we used newly developed multichannel recording system for monitoring the simultaneous electrical activities of many neurons in a functioning piece of retina. Retinal action potentials are recorded with an extra-cellular planar array of 60 microelectrodes. In studying the collective activity of the ganglion cell population it is essential to recognize basic functional distinctions between individual neurons. Therefore, it is necessary to detect and to classify the action potential of each ganglion cell out of mixed signal. We programmed M-files with MATLAB for this sorting process. This processing is mandatory for further analysis, e.g. poststimulus time histogram (PSTH), auto-correlogram, and cross-correlogram. We established MATLAB based protocol for waveform classification and verified that this approach was effective as an initial spike sorting method.

• Korean Journal of Cognitive Science
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• v.4 no.1
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• pp.51-86
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• 1993

The purpose of this study was to investigate on-line comprehension processing in pronoun resolution. The two important constraints investigated in this study were the gender cue of pronoun and the antecedent case. Using antecedent probe recognition task. Experiment 1 investigated the effects of gender cues and antecedent cases on probe recognition time. There were on signigicant effects of employed variable. This result suggest the possibilty of immediate antecedent assignment depending on the degree of syntactic constraints satisfaction. In Experiment 2. using antecedent probe recognition task. the primed activation level differences between antecedents and non-antecedents over time-course intervals from 0 to 250msec were measured. The effect of gender cues was obtained over 0-250msec time-course condition. This indicates that the gender cues can determine the assignment of proper antecedent for a pronoun. In Experiment 3, subect-case pronouns were used only:Unambiguous gender cues were given and the time-course intervals of 250 and 750msec were employed. A signigicant interaction effect of antecedent cases with probe conditions was obtained. All the results of this research suggest that gender cues are powerful constraints for pronoun resolution.

• Science of Emotion and Sensibility
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• v.22 no.4
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• pp.57-64
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• 2019

Anger is the most common emotional trigger causing relapses in individuals with alcohol use disorders (AUDs). The present study intended to investigate the autonomic nervous system (ANS) responses induced by anger in individuals with AUDs. The participants in this study included twelve individuals with AUDs and 14 non-frequent drinkers. Anger was induced in the participants via a 120-second film clip. Before the presentation of this audio-visual stimulus, the ANS responses of the participants were measured for 60 seconds to ascertain their resting state. Subsequently, the participants' ANS responses were measured again for 120 seconds when they were in an emotional state during the presentation of the clip. After the ANS measurements were taken, participants were asked to rate the type of emotion they had experienced as they viewed the film and to report its intensity. The results indicated that the levels of anger experienced by the AUD group were not significantly different from the emotion registered by the control group. However, the ANS responses induced in AUD participants when they were in an emotional state showed blunted skin conductance levels (SCL) and skin conductance responses (SCR) compared to the control group participants. Individuals with AUDs evinced lower emotional arousal than the participants of the control group. These results can help clinicians understand the psychological and physiological responses of individuals with AUDs to anger in order to design effective interventions that would reduce chances of anger and relapse.