• Korean Journal of Cognitive Science
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• v.11 no.3_4
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• pp.83-93
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• 2000

The effect of immediate and delayed recognition memory on event-related potential (ERP) was studied using a continuous recognition memory task and event-related potential (ERP). Among 240 stimulus words 40 words were not repeated. 100 were immediately repeated and 100 were repeated after 5 intervening words. All words presented only once during the experiment were referred to as new words. Subjects responded faster and more accurately to words repeated immediately than to new words a and to those repeated after intervening words. In terms of ERP results the immediately repeated words were associated with large P300 amplitude, early P300 latency and a absence of N400. while words repeated after a delay were associated with small P300 a amplitude. late P300 latency and the presence of N400. N400 was elicited only to new w words and to those repeated after a delay. The general morphology of the waveform was s similar for three stimulus-presentation conditions until around 3l0ms after the onset of stimulus. These results indicate that immediate and delayed recognition memory could be dissociated into two distinct processes possibly being mediated by different cerebral mechanism, and the dissociation between two types of recognition memory emerges around 3l0ms poststim'ulus. The immediate and delayed recognition memory for words are considered in terms of template matching and memory searching.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.10
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• pp.5003-5011
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• 2013

This paper measured whether neural and behavior responses to attention-emotion task were reflected to emotion regulation capacities. For this purpose, Nineteen healthy right-handed graduates participated in the emotion-attention task three times for three days. Before and after the negative and positive video clips were shown, the participants performed emotion-attention task. EEG and response time were recorded during emotion-attention task. There was positive correlation between ERP P100 and P300 component. The larger the P100 amplitudes at the specific positions, the longer the P300 latencies at these same positions during attention-emotion task. The longer the P300 latencies at the specific positions, the longer the delay in response time. Also, there is and individual differences in ERP components and response time during attention-emotion integration task. Individuals who had lower amplitude and shorter latency of ERP showed faster response time during attention-emotion task, regardless of the type of video clips. This characteristic was interpreted to the lower emotional controls due to premature response for target identification.

• Journal of Ginseng Research
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• v.36 no.2
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• pp.190-197
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• 2012

Ginseng has a long history of use for health enhancement, and there is some evidence from animal studies that it has a beneficial effect on cognitive performance. The purpose of this study was to investigate the effect of Korean red ginseng on cognitive performance in humans. A total of 15 healthy young males with no psychiatric or cognitive problems were selected based on an interview with a board-certified psychiatrist. The subjects were randomly assigned to receive a daily dose of 4,500 mg red ginseng or placebo for a 2-week trial. There were 8 subjects in the red ginseng group and 7 subjects in the placebo group. All of the subjects were analyzed with the Vienna test system and a P300 event-related potential (ERP) test. There were no significant differences in the Vienna test system scores between the red ginseng group and the placebo group. In the event-related potential test, the C3 latency of the red ginseng group tended to decrease during the study period (p=0.005). After 2 wk, significant decreases were observed in the P300 latencies at Cz (p=0.008), C3 (p=0.005), C4 (p=0.002), and C mean (p=0.003) in the red ginseng group. Our results suggest that the decreased latency in ERP is associated with improved cognitive function. Further studies with a higher dosage of ginseng, a larger sample size, and a longer follow-up period are necessary to confirm the clinical efficacy of Korean red ginseng.

• Science of Emotion and Sensibility
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• v.18 no.2
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• pp.85-100
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• 2015

This study aimed at examining if the original memory remains after a misinformation is presented, using Event-Related Potential based Concealed Information Test (ERP-based CIT). In the first stage of the study, the participant was presented with either the original information or a misleading information after experiencing an event (Post-information). The second stage was to measure brain wave and reaction time on the original, misleading, and irrelevant information (CIT-Stimulus). P300 amplitude, P300 area, P300 latency, and reaction time were used as dependant variables. In the result, a significant Post-information ${\times}$ CIT-Stimulus interaction effect was found on the P300 area measured at Cz, Pz, and Oz area. This interaction effect implied the possibility that the original information could be partially impaired in memory by misleading information presented afterward. P300 amplitude at Pz area did not differ between the accurate and the misleading stimuli in the condition in which a misleading information was presented. This result can be explained by source monitoring error. In discussion, the limitations of this study and directions of future studies were discussed.

• Sleep Medicine and Psychophysiology
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• v.10 no.2
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• pp.108-112
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• 2003

Objectives: The purpose of this study is to investigate the psychophysiological effects of total sleep deprivation by using auditory event-related potentials. Methods: Twenty four healthy college students (18 men, 6 women) participated in this study. The subjects remained awake for 37 hours under continuous surveillance. In the morning and the evening of two consecutive study days, auditory event-related potentials were checked. Results: The latencies of P300 and N200 were significantly prolonged (p<0.001) and their amplitudes decreased (p<0.05) as a consequence of sleep deprivation. The amplitude of P200 was significantly increased during sleep deprivation (p<0.05). However, there was no significant change in the latency and amplitude of N100. Conclusion: Among the components of auditory event-related potentials, P300 and N200 are good indicators of sleep-deprived status. Further investigation is necessary to elucidate the neurophysiological mechanisms of these findings.

• Korean Journal of Cognitive Science
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• v.16 no.2
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• pp.141-154
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• 2005

The purpose of this study was to investigate the effects of implicit and explicit situation awareness instruction on decision making and event related brain potentials. Psychophysiological data obtained from 36 intermediated level tennis players whose National Tennis Rating Program(NTTP) belong 2 to 2.5 were compared. Participants were randomly assigned to one of three experimental groups: (1) implicit situation awareness, (2) explicit situation awareness, and (3) control group. A total of 90 clips were presented via a beam project screen, and participants pressed one of three jelly bean buttons to indicate the direction of ball hit. Dependent measures were the latencies and amplitudes of P300 on Pz, Cz, and Fz. The results of this study indicated that participants in the implicit situation awareness produced tenser P300, than participants in the explicit situation awareness group. The findings also indicated that single defense showed longer P300 latencies than single attack as well as double defense. The P300-amplitude of treatment groups were longer than control group. The Cz area showed shorer P300 latencies than Pz and Fz areas. In addition, single defense situation demonstrated longer P300 latencies than single attack and double defence situations. Based on this study, it is believed that implicit and explicit situation awareness instruction influence decision making in different ways.

• The Journal of the Korea Contents Association
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• v.16 no.5
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• pp.242-250
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• 2016

This study was conducted to investigate whether Stroop-related cognitive task will be affected according to the preceding affective valence factored by matchedness in response time(RT) and whether facial recognition will be indexed by specific event-related potentials(ERPs) signature in normal person as in patients suffering from affective disorder. ERPs primed by subliminal(30ms) facial stimuli were recorded when presented with four pairs of affect(positive or negative) and cognitive task(matched or mismatched) to get ERP effects(N2 and P300) in terms of its amplitude and peak latency variations. Behavioral response analysis based on RTs confirmed that subliminal affective stimuli primed the target processing in all affective condition except for the neutral stimulus. Additional results for the ERPs performed in the negative affect with mismatched condition reached significance of emotional-face specificity named N2 showing more amplitude and delayed peak latency compared to the positive counterpart. Furthermore the condition shows more positive amplitude and earlier peak latency of P300 effect denoting cognitive closure than the corresponding positive affect condition. These results are suggested to reflect that negative affect stimulus in subliminal level is automatically inhibited such that this effect had influence on accelerating detection of the affect and facilitating response allowing adequate reallocation of attentional resources. The functional and cognitive significance with these findings was implied in terms of subliminal effect and affect-related recognition modulating the cognitive tasks.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.35 no.1
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• pp.90-97
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• 2024

Objectives: This study aimed to explore the influence of depression severity, disease course, treatment status, and other factors on cognitive function in adolescents with depressive disorders. Methods: Participants who met the inclusion criteria were enrolled in the study. Sociodemographic data of each participant were recorded, including age, sex, and family history of mental disorders. Zung's Self-Rating Depression Scale was used to assess depression status in adolescents. Moreover, P300 and mismatch negativity (MMN) were used to objectively evaluate the participants' cognitive function. Results: Only 26.8% of the adolescents with depression received standard antidepressant treatment. The latencies of N2 (267.80±23.34 ms), P3 (357.71±32.09 ms), and MMN (212.10±15.61 ms) in the adolescent depression group were longer than those in the healthy control group (p<0.01). Further analysis revealed that the latency of MMN was extended with increased levels of depression in adolescents. The MMN latency was short in participants with depression receiving standardized treatment. Furthermore, the latency of MMN was positively correlated with the severity and duration of depression (correlation coefficients were 0.465 and 0.479, respectively) (p<0.01). Conclusion: Receiving standardized treatment and shortening the course of depression can reduce cognitive impairment in adolescents with depression.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.5
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• pp.976-988
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• 2002

The aim of this study was to examine the memory and attention enhancement effect of YMG-1 and YMG-2, which are modified herbal extracts from Yukmijihwang-tang (YMJ). YMJ, composing six herbal medicine, has been used for restoring the normal functions of the body to consolidate the constitution, nourishing and invigorating the kidney functions for hundreds years in Asian countries. A series of studies reported that YMJ and its components enhance memory retention, protects neuronal cell from reactive oxygen attack and boost immune activities. Recently the microarray analysis suggested that YMG-1 protects neurodegeneration through modulating various neuron specific genes. A total of 55 subjects were divided into three groups according to the treatment of YMG-1 (n=20), YMG-2 (n=20) and control (C; n=15) groups. Before treatments, all of subjects were subjected to the assessments on neuropsychological tests of K-WAIS test, Rey-Kim memory test, and psychophysiological test of Event-Related Potential (ERP) during auditory oddball task and repeated word recognition task. They were repeatedly assessed with the same methods after drug treatment for 6 weeks. Although no significant effect of drug was found in Rey-Kim memory test, a significant interaction (P = .010, P < 0.05) between YMG-2 and C groups was identified in the scores digit span and block design, which are the subscales of K-WAIS. The very similar but marginal interaction (P = .064) between YMG-1 and C groups was found too. In ERP analysis, only YMG-1 group showed decreasing tendency of P300 latency during oddball task while the others tended to increase, and it caused significant interaction between session and group (p= .004). This result implies the enhancement of cognitive function in due to consideration of relationship between P300 latency and the speed of information processing. However, no evidence which could demonstrate the significant drug effect was found in neither amplitude or latency. These results come together suggest that YMG-1, 2 may enhance the attention, resulting in enhancement of memory processing. For elucidating detailed mechanism of YMG on learning and memory, the further studies are necessary.

• Korean Journal of Cognitive Science
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• v.22 no.3
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• pp.255-270
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• 2011

The purpose of this study was to examine the effects of nonspecific and specific cue on decision making during situation awareness. Participants were 36 male college students who were randomly assigned to one of three groups: (1) nonspecific situation awareness, (2) specific situation awareness, and (3) a control group. Every participant was in the level 3-4.5 according to American National Tennis Level Program. Participants were asked to watch tennis single defence, single offence, double defence rally and when the screen stops, they were required to push the button(left, middle, or right) appropriate for the ball's direction to return as soon as possible. The experiment was designed to be analyzed for group(3)${\times}$condition(3)${\times}$area(7) using three-way ANOVA. The dependent variables were reaction time, accuracy rate, and amplitude and latency of P300. The result showed that the latency of the nonspecific situation awareness group and the specific situation awareness group was shorter and their amplitudes were higher than the control group. Fz, Cz, Pz were prominent among areas, and the single defence condition was more prominent than the single offence and the double defence condition. As a result of the study, it can be suggested that the information about situation awareness provided beforehand directly affects the brain's information processing. In addition, it shows that ERP can be a useful index for studying situation awareness.