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- P-ISSN1226-9654
- E-ISSN2733-466X
- KCI
ISSN : 1226-9654
Vol.31 No.2
Abstract
We investigated the long-term effects of combined stress using adolescent and adult rats and determined whether there were differential effects depending developmental periods. The combined stress consisted of social isolation and chasing stress. The adolescent (5-weeks old) and adult (8-weeks old) rats were isolated three days prior to chasing stress. Both groups of the rats were assigned to social isolation (SI) or social isolation + chasing stress (SI+C) treatment. Chasing stress is a novel stress paradigm developed by the authors, in which the rats were chased by a fast-approaching robotic construct in an inescapable donut-shaped maze. Three weeks following the chasing stress, the rats were examined for long-term memory of the chasing tone, anxiety-like behavior, and new fear learning. In the chasing tone test, the adolescent SI+C showed a lower level of freezing in response to the chasing tone itself than the adult SI+C. However, there were no differences in freezing levels during inter-trial intervals. In the elevated plus-maze (EPM) test, the adolescent SI+C exhibited increased anxiety-related behaviors, but the adult SI+C did not. In the fear conditioning using footshock, the adult SI+C showed sensitized responses, whereas the adolescent SI+C showed impairment of new fear learning. In sum, the combined stress experienced during adolescence caused long-term disability in reacting properly to a warning cue as well as increased anxiety-related behavior. On the contrary, these effects were not induced by the same treatment during adulthood. Therefore, we propose that combined stress during adolescence, which consisted of social isolation and chasing stress, could be employed as an animal model of anxiety with consideration of the vulnerability of adolescents to anxiety disorders. Further studies are warranted to prove the utility of the new model and the underlying brain mechanism.
Abstract
Signed languages are generally more dominant in visual modality than spoken languages. This study (N=29) examined whether the “tip of the fingers (TOF)” phenomenon for sign language would parallel to the “tip of the tongue (TOT)” phenomenon for spoken language. TOF occurred among Korean signers, and specifically, Korean signers were more likely to retrieve a target sign’s hand shape, location and orientation than to retrieve its movement. The existence of TOFs supported a separation between semantic and phonological representations in Korean Sign Language. The link between meaning and phonology was activated automatically for high iconic properties of a sign. These results were consistent with those of previous research on American Sign Language.
Abstract
We investigated event-related potential generators in the P300-based guilty knowledge test using Korean sentences, which had an ‘object-complement-verb’ or a ‘subject-object-verb’ structure. Twenty-six participants were divided into a guilty group and an innocent group. Thirteen guilty participants performed a mock theft, and 13 innocent participants committed a crimeless act. During electroencephalogram recording, 3 kinds of stimuli were visually presented: target, probe, which included crime-relevant information, and irrelevant. The results of event-related potentials showed that the P300 amplitude for the probe sentence was larger than the irrelevant sentence in the guilty group; however, the innocent group did not show such difference. The equivalent current dipole analysis for the probe found a group difference of dipole location and power. In both groups, the sources of probe of verb element were determined to be located in the superior frontal gyrus. The guilty participants exhibited significant alterations in the hemispheric asymmetry of dipole power for the probe of verb element. This result seems to reflect that guilty participants have crime-relevant information and pay more attention to the probe compared to the innocent participants. This study also shows hemispheric asymmetry in the deceptive response using sentences.
Abstract
Impaired working memory (WM) is the most reliably reported cognitive dysfunction in schizophrenia. Past research have revealed that increased novelty or salience of visual stimuli could facilitate the WM process, which is not clear in schizophrenia yet. In the present study, we investigated WM performance of healthy people and patients with schizophrenia using biological motion (BM), which is unique motion stimulli carrying rich social information. Experiment 1 examined WM accuracy for BM and non-BM stimuli in low- and high-memory load conditions. In experiment 2, we investigated WM for BM, non-BM and static polygon stimuli in three different delay conditions. The results showed that overall performance was worse in the patients group. WM accuracy for BM stimuli did not drop and remained higher than those for the other stimuli regardless of increasing memory load and delay in control group. Patients group also showed higher accuracy for BM stimuli than the other stimuli across the conditions but it decreased with incresing load and delay, unlike controls. Our findings suggest that socially-relevant stimuli such as BM could facilitate WM in schizophrenia and it may provide a clue of target for cognitive remediation strategies.
Abstract
This study was designed to investigate the age-related differences in valence and arousal ratings for stimulus materials. In this study, older (n=50) and young adults (n=50) rated 54 emotional faces in terms of valence and arousal using a 7-point scale. Older adults reported happy and neutral faces as being more positive and angry faces as being more negative than young adults did. A similar pattern was evident for arousal. Older adults rated negative and neutral faces as being more arousing than young adults did. This suggests that the older adults have a tendency to respond to emotional faces more extremely. Furthermore, whereas older adults showed a linear association between valence and arousal, young adults showed a U-shaped function. Clinical implications and limitations of the current findings are discussed.
Abstract
Two experiments were conducted to examine how visual complexity and character structure influence Hangul perception. To this end, we manipulated visual complexity using a perimetric complexity metric and character structure in Experiment 1. We used only consonants as stimuli in Experiment 2. We implemented a trigram presentation method where participants were asked to report the presented trigram as accurately as possible. In Experiment 1, the results showed that accuracy rates in the simple visual complexity condition were higher that those in the complex condition, and that when visual complexity was controlled, the effect of character structure was significant such that the CV stimuli showed lower accuracy rates than the CVC stimuli did. In Experiment 2 where the trigrams consisted of only consonants demonstrated that overall accuracy was higher in Experiment 2 than Experiment 1, and that it was higher when the stimuli were presented in the right visual field relative to when they were in the left visual field. We discussed these results in relationship with findings in previous literature, especially with respect to the crucial role of visual complexity in perceptual processes in Korean.
Abstract
This study investigated that the somatizing tendency group would have both attentional biases and memory biases for somatic-symptom words. As a result of previous studies, the tendency of somatization consistently showed a tendency of bias in somatic symptoms-related words. The purpose of this study is to investigate the bias of somatic symptoms-related words using probing task. Also, the aim of this study indicates that significant impairment in memory inhibiting affects people of somatizing tendency group differently from the normal people. The subjects were college students who showed high somatizing tendency at Somatic Symptoms Index(SSI-3/5) developed by Rief in 1996. As a result, First, the somatizing tendency group presented significant short reaction time for somatic-symptoms words in 2000m sec. Second, The results of the test show that the RIF effect both types of words(somatic symptoms related & neutral) has been found on control group. The RIF effect of somatic symptoms words, however, has failed to affect the test result of the somatizing group. In other words, the somatizing tendency group more remembered the somatic-symptom words than the neutral words. These results suggested that the somatizing patients group have both attentional biases and memory biases for somatic-symptom words. Therefore, the hypothesis in which the somatizing patients group would have both attentional biases and memory biases for somatic-symptom words was partly supported
Abstract
The purpose of this study was to investigate the relationship between the self-reported aggressiveness level measured by the Korean version of Aggression Questionnaire (K-AQ), and the computerized cognitive tasks (emotion perception task and mental rotation task). Participants were divided into three groups according to their self-reported aggressiveness levels (low-range, middle-range, and high-range), and their performances in the two computerized cognitive tasks were examined. Results demonstrated that in emotion perception task, the low-range K-AQ score group showed a lower bias score toward negative emotion perception compared to middle-range and high-range groups. This suggests that there was an increase in the tendency of participants to show a negative emotional bias to a certain extent with increased level of self-reported aggressiveness, and the level of negative emotional bias seems to be maintained once the aggressiveness level reaches the higher-end of the spectrum. However, there was no significant group difference for the bias score toward positive emotion perception. In mental rotation task, there was a significant group difference in response times, where participants in the middle-range aggression group showed slower response times compared to both low-range and high-range groups. But, there was no group differences in their accuracy rates. This suggests that visuo-spatial representation ability may not be static in nature but it seems to decline to a certain extent in accordance to the aggressiveness level. This exploratory study has examined the negative emotion perception bias and visuo-spatial representation ability in relation to the level of aggression by dividing the aggressiveness level into three levels. The implications of investigating human emotion on a continuous spectrum is discussed.
Abstract
The current study aimed to examine how the anxious mood state affects human directional choice. For this purpose, we employed a version of the spatial Stroop task and tested the effect of the induced anxious mood state on the facilitation and interference effects. In an experiment, neutral and anxious picture-and-sound sets were employed to manipulate different moods between two groups. After the mood induction, participants performed a version of the spatial Stroop task that included congruent, neutral, and incongruent trials. The results showed that an anxious mood enhanced the facilitation effect, but reduced the interference effect. In contrast, the conflict adaptation effect was not influenced by the anxious mood. These findings suggest that an anxious mood can accelerate target processing through enhancing focused attention but not inhibitory control. The practical implications for human directional choice in an evacuation situation are discussed.
Abstract
The expression ‘what looks good tastes good’ implies a close relationship between taste and visual information. In particular, color information has been considered to significantly influence taste perception. The current study explored the effects of color information on the taste perception of chocolate, a representative favorite food. A preliminary experiment exploring color-taste associations found that yellow is strongly associated with sour tastes and green with bitter tastes. These colors were selected as stimuli in the main experiment. Two batches of white chocolate were colored with flavorless yellow and green food coloring, respectively, while a third batch was left uncolored as a control stimuli. This process yielded three colors of chocolate with the same taste. After eating one randomly assigned piece of chocolate of the three colors, each participant was asked to rate its sweet, sour, and bitter characteristics on a seven-point scale. The study found that the yellow chocolate scored a significantly higher sour rating than chocolates with the other colors. These results show that expectations based on color information can influence the taste perception of chocolate.