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The purpose of this study was to measure the average corpus callosum volume of normal Koreans (aged in their 20s or 40s) and to analyze the effects of gender, age, and body parameters, such as height and weight on corpus callosum size. Magnetic resonance brain images were recorded for 68 people in their 20s (29 men, 39 women) and 91 in their 40s (36 men, 55 women). Intracranial volume was calculated using cerebral size and corpus callosum volume was normalized by covariance method. To investigate the effect of gender and age on corpus callosum volume, two-way analysis of variance, which used gender (two levels) and age (two levels) as independent variables, was employed. Multiple regression analysis was carried out to investigate the effect of body parameters, such as height and weight, according to the age and gender on the changes in corpus callosum volume. The average corpus callosum volume of Korean men (11.09 cm3) was larger than that of Korean women (9.61 cm3). There was no significant difference in corpus callosum volume between 20s (10.43 cm3) and 40s (10.12 cm3). There was a positive relationship between body weight and corpus callosum volume for 20s, but not for 40s. [ABSTRACT FROM AUTHOR]

Emotions are experienced differently by individuals, and thus, it is important to account for individuals' experienced emotions to understand their physiological responses to emotional stimuli. The present study investigated the physiological responses to a fear-inducing stimulus and examined whether these responses can predict experienced fear. A total of 230 participants were presented with neutral and fear-inducing film clips, after which they self-rated their experienced emotions. Physiological measures (skin conductance level and response: SCL, SCR, heart rate: HR, pulse transit time: PTT, fingertip temperature: FT, and respiratory rate: RR) were recorded during the stimuli presentation. We examined the correlations between the physiological measures and the participants' experienced emotional intensity, and performed a multiple linear regression to predict fear intensity based on the physiological responses. Of the participants, 92.5% experienced the fear emotion, and the average intensity was 5.95 on a 7-point Likert scale. Compared to the neutral condition, the SCL, SCR, HR, and RR increased significantly during the fear-inducing stimulus presentation whereas FT and PTT decreased significantly. Fear intensity correlated positively with SCR and HR and negatively with SCL, FT, PTT, and RR. The multiple linear regression demonstrated that fear intensity was predicted by a combination of SCL, SCR, HR, FT, and RR. Our findings indicate that the physiological responses to experiencing fear are associated with cholinergic, sympathetic, and α-adrenergic vascular activation as well as myocardial β-sympathetic excitation, and support the use of multimodal physiological signals for quantifying emotions. [ABSTRACT FROM AUTHOR]

This study investigated what effect a 30% oxygen administration had on visuospatial cognitive performance and cerebral activation and lateralization using fMRI. Eight college students were selected as the subjects for this study. An oxygen dispenser that provided 21% and 30% oxygen at a constant rate of 8L/min was developed. In order to measure the performance level of visuospatial cognition, two psychological tests were also developed. The experiment consisted of two runs, one for a visuospatial cognition task with normal air (21% oxygen) and the other for a visuospatial cognition task with hyperoxic air (30% oxygen). Functional brain images were taken with a 3T MRI using the single-shot EPI method. The results of the visuospatial behavioral analysis reveal that accuracy rates were enhanced with 30% oxygen administration when compared to 21% oxygen. There were more activations observed at the bilateral occipital, parietal, and frontal lobes with 30% oxygen administration. However, decreased cerebrum lateralization was observed with 30% oxygen administration in the same regions compared with 21% oxygen administration. Thus, it is concluded that the positive effect on the visuospatial cognitive performance level by the highly concentrated oxygen administration resulted from an increase of cerebrum activation and a decrease of cerebrum lateralization. [ABSTRACT FROM AUTHOR]