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- P-ISSN1226-9654
- E-ISSN2733-466X
- KCI
ISSN : 1226-9654
Vol.20 No.4
Abstract
This research examined the role of midfrontal EEG asymmetry in the regulation of negative emotions. Frontal brain asymmetry(FBA), heart rate(HR), respiratory sinus asymmetry(RSA), and skin conductance level(SCL) were recorded during baseline, relaxation, worry induction, anticipation of impromptu speech task and recovery. The relative left activation group showed lower distress rating than the right activation group at the end of the anticipation period and after the speech task. Participants with relatively higher left activation showed lower HR, and higher RSA than those with relatively higher right activation group during worry and anticipation task. The relatively higher right activation delayed recovery from higher HR and lower RSA due to speech task. Compared with baseline, relaxation increased left midfrontal cortex activity, but both worrying and anticipation decreased left midfrontal EEG activity. Worrying and anticipation was associated with greater HR, lower RSA and greater SCR compared with both baseline and relaxation. These findings support the role of FBA in the negative emotion regulation. Implications and limitations of the research are discussed.
Abstract
Visual cues emitted from a speaker, such as mouth and lip movements, are critical aspects of sensory information that influence auditory speech perception in face to face conversation. The way in which these complex visual cues are processed remains to be elucidated. Here we apply fMRI to a cross-modal speech perception paradigm in order to determine how functional connectivity between brain areas changes depending on the type of visual cue. Data obtained from a previous fMRI study in which three conditions, closed mouth (CM), twitching mouth (TM), or speaking mouth (SM) were delivered during an auditory sentence perception task. Structural Equation Modeling (SEM) was used to estimate functional strengths of links in a network among the brain regions activated in these three conditions. The chosen brain areas, which were modeled only in the right hemisphere, consisted of visual areas (lingual gyrus and V5/MT), both anterior and posterior superior temporal sulci (aSTS and pSTS), and the area equivalent to left Broca’s area (rBroca’s). Significant differences were found for the functional linkages between V5/MT and rBroca’s area across the three conditions. The path from V5/MT to rBroca became positive both during the TM and SM conditions, whereas that in the CM condition was negative. However, the connection from rBroca to V5/MT became negative both during the TM and SM, whereas that in the CM condition was positive. Additional linguistic information, such as the mouth movements of the SM condition, resulted in increased statistical significance of these linkages relative to the TM condition. The dynamic changes in functional connectivity between V5/MT and Broca’s area in the right hemisphere may subserve the cross-modal processing of auditory speech by inhibiting irrelevant or interfering visual cues from mouth movement.
Abstract
This review aims to specify problems and to explain the reason why they occur when measuring event-related potentials (ERPs)--N2pc(N2 post-contralateral) component often used in recent studies of visual attention. For these purposes, an overview of N2pc measurement technique to observe an attention shift in visual search was provided, and several solutions for the problems were discussed. Presence of N2pc component is determined according to a more negative-going potential in EEG amplitude measured from the electrodes that are contralateral to the target than those ipsilateral, elicited about 200ms after the search array onset. Generally, the amplitude difference between the contra- and ipsilateral electrodes becomes maximal when attention shifts to the target location, and the moment of this attention shift can be sought by systematic tests of the amplitude and latency of N2pc component. N2pc measurement requires high signal-to-noise ratio, and this can be accomplished by minimizing any noise occurring when EEGs are initially recorded online. Eye movements to a target position can exaggerate the N2pc contra-ipsi difference and thus trials with saccades toward the target position are typically rejected rather than corrected. To minimize lateralized readiness potentials (LRPs) possibly evoked by any lateralized search target, it is recommended to use only one hand for responses while switching the hand across blocks to counterbalance handedness.
Abstract
In this study, the effects of cast shadow directions on visual search were investigated. Rensink and Cavanagh(2004) reported that search based on cast shadow can have a significant influence on the speed of visual search. Here we manipulated directions of cast shadow and arrangement positions, to test whether there is a preferred direction of illumination in the processing of cast shadow. Target and distracters had identical cast shadow directions, and target differed from distracters only in the orientation of cast shadow. In Experiment 1, two-dimensional shapes were used consisting of vertically oriented rectangles and quadrilateral, and in Experiment 2, three-dimensional cylinders were adopted. Results show that search was consistently slower for the normal ground arrangement than for the ceiling arrangement across the conditions. In addition, cast shadow directions had asymmetric effects on search time, depending on the object types. When the stimuli were arranged on the ground, search for the left-lit condition tended to be slower than for the right-lit condition in Experiment 1, whereas search for the left-lit condition tended to be faster than for the right-lit condition in Experiment 2. These findings imply that the processing of right-side cast shadow seems to be more influenced by objects' 2- or 3-dimensional property than that of left-side one. It is suggested possible differential processing related with the fact that human perceives as more familiar scene left-lit world where the shadow is cast on right-side.
Abstract
Data from our laboratory indicate that application of the mu agonist DAMGO into the basolateral complex of amygdala (BLA) suppresses tail flick reflexes in anesthetized rats. This DAMGO-induced antinociception can be blocked by pretreatment of the BLA with the nonselective opioid antagonist naltrexone, the mu opioid antagonist β-FNA, or the G protein inhibitor pertussis toxin, suggesting that DAMGO's interaction with G protein-coupled mu receptors in the BLA leads to production of antinociception. The present study employing the gene control strategy was conducted to further investigate the direct action of DAMGO on the mu receptors in the BLA. Intra-BLA application of antisense oligodeoxynucleotides (ODN) against mu receptors blocked antinociception following intra-BLA injection of DAMGO. The amount of [3H]-DAMGO binding to mu receptors in the amygdala was also reduced in the antisense ODN-pretreated rats. These data confirm the idea that antinociception induced by DAMGO in the BLA results from a direct interaction of DAMGO with mu receptors in the amygdala.
Abstract
This study examined the effects of amygdala inactivation on the expression of conditioned fear and the performance of active avoidance. Rats, with chronic cannulae placed bilaterally in the amygdala, were given 30 active avoidance training trials for 3 days and 1 or 2 days later tested for conditioned fear and active avoidance immediately after muscimol or buffer injection into the amygdala. As a result, activity to the CS in the amygdala inactivation group was larger than that of controls while performance of active avoidance was not different. In other words, amygdala inactivation impaired expression of conditioned fear but not active avoidance response. These findings suggest that both memory storage and memory modulation, different view about the role of amygdala, are correct in part and the discrepancy between the two stems from the task difference in part. Thus, amygdala seems to be the locus of CS-US association and, at the same time, modulates memory consolidation in other brain regions. It means that neural mechanisms for the expression of conditioned fear and the performance of active avoidance are not the same.
Abstract
This study compared data from web-based psychological experiments and self-reporting questionnaires with data from laboratory experiments and paper-pencil tests to verify the validity of web-based psychological assessment. In study 1, a total of 14 subjects participated in a comparative experiment, in which each participant performed both laboratory and two types of web-based attention tasks(IOR and CPT). The results of paired-sample t-test, there were no significant differences between the measurements for two different formats. This result may show the equivalence of the results from the two types of experiments(lab-based and web-based). In study 2, we examined paired-sample t-test and test-retest pearson correlation of each self-reported questionnaire subscale to evaluate if there were statistically significant differences between paper-pencil and web-based formats. The results revealed that mean subscales for two formats were not significantly different and subscale scores were highly correlated with each other. This results also suggested that web-based questionnaire data can be dealt equivalently with paper-pencil administered data.
Abstract
This study investigated whether participants adopted different categorization strategies to learn categories according to their cognitive styles. At first, participants were classified into two types of processor, analytic processors and wholistic processors by Riding(1991)'s cognitive style analysis(CSA). Manipulating linear separability of category structure, learning speed of two processors were compared in Experiment 1. Results showed that analytic processors learned linearly separated categories more quickly than wholistic processors, and wholistic processors reminded learned exemplars more accurately than analytic processors. In Experiment 2, Analyzing categorization patterns of subjects individually, hypothesis was tested that two processors used different categorization strategies to learn categories. Experiment 2's hypothesis was confirmed partially. In conclusion, analytic processors learned categories by focusing attention on relevant features and wholistic processors by comparing similarity between new exemplar and learned exemplars.
Abstract
An experiment was conducted to examine the conceptual systems for Korean-English unbalanced bilinguals. The main focus was to examine whether the conceptual systems of Korean and English words are shared or independent. A primed lexical decision task was used and two types of semantic priming were compared: within-language and cross-language. The pattern of priming was very different, which suggests that Korean and English conceptual systems are not the same for Korean-English unbalanced bilinguals. Instead, it seems that they are connected but independent systems.