Siekyeong Kim

Volume of hippocampal subfields in patients with alcohol dependence

Alcohol-induced hippocampal atrophy has been well documented in many studies and is known to affect various subfields. Given the functional heterogeneity of these subfields, we investigated the precise effects of alcohol-induced damage in these areas. Twenty-six male patients with alcohol dependence (alcohol group) and twenty-six age-matched male healthy social drinkers were recruited from a mental health hospital and the community respectively, with the aim of comparing the hippocampal subfields between groups. Each participant underwent a 3T MRI scan. Hippocampal subfield volumes were estimated using an automated procedure and drinking history recorded using Lifetime Drinking History, Alcohol Use Disorder Identification Test, and the Brief Michigan Alcoholism Screening Test. The alcohol group showed a lower total hippocampus volume, specifically in the left presubiculum, fimbria, and bilateral subiculum. Regression analysis assessing the influence of age and group showed that group was a more significant factor than age in most subfields. Our findings suggest that alcohol dependence alters hippocampal subfield volumes. Further longitudinal studies on the interaction of structural and neurocognitive changes would improve our understanding of brain structural changes resulting from long-term alcohol consumption.

A Study of Covert Narcissism in Adolescent Internet Addiction : Relationship to Anonymity, Presence, Interactivity, and Achievement Motivation

Objectives:This study compared covert narcissistic propensity in adolescents with internet addiction tendency to normal adolescents. Further, we investigated the correlation between such propensities and anonymity in cyberspace, presence feeling and interactivity in internet gaming, and achievement motivation in adolescents with internet addiction tendencies. Methods:Male middle school students with internet addiction tendencies (Addiction Tendency Group, N=27) and normal stu- dents (Control Group, N=29) were recruited. The scale of internet use, Covert Narcissism Scale, scale of achievement motiva- tion, scale of anonymity in cyberspace, scale of presence feeling in internet games, and the scale of interactivity in internet games were administered. A comparison of the average scores and correlation analyses were performed. Results:1) Compared with Control Group, the Addiction Tendency Group showed significantly higher scores on all subscales of the Covert Narcissism Scale, and both the scale of presence feeling and that of interactivity in internet games. Further, the score on the scale of achievement motivation for the Addiction Tendency Group was significantly lower than that of the Control Group. 2) In the Addiction Tendency Group, the scores on several subscales of the Covert Narcissism Scale were significantly positively correlated with the scores on the scale of presence feeling in internet games, anonymity in cyberspace, and interac- tivity in internet games. However, in the Control Group, the scores of several subscales on the Covert Narcissism Scale were sig- nificantly negatively correlated with the score on the scale of achievement motivation, and was significantly positively correlat - ed with the score on the scale of interactivity in internet games. There were no other significant correlations between the scores on the subscales of the Covert Narcissism Scale and the scores of either presence feeling in internet games or anonymity in cy- berspace.

Disrupted Control Network Connectivity in Abstinent Patients with Alcohol Dependence

Objective Alcohol causes damage to the brain and is associated with various functional impairments. However, much of the brain damage can be reversed by abstaining for enough time. This study aims to investigate the patterns and degrees of brain function in abstinent patients with alcohol dependence by using resting-state functional connectivity. Methods 26 male patients with alcohol dependence (alcohol group) and 28 age-matched male healthy volunteers (control group) were recruited from a mental hospital and the community, respectively. Using 3T MRI scan data, the resting-state functional connectivity of the task-negative and task-positive networks was determined and compared between the groups. Results There were no significant group differences in the resting-state functional connectivity in the default mode or in the salience and sensorimotor networks. Compared with the control group, the alcohol group showed significantly lower functional connectivity in the executive control network, especially in the cingulo-opercular network and, in some regions of interest, the dorsal attention network. Conclusion This finding suggests that some brain networks do not normalize their functions after abstinence from drinking, and these results may be helpful in future research to investigate the mechanisms for craving alcohol and alcohol relapse prevention.

An fMRI Study Investigating Adolescent Brain Activation by Rewards and Feedback

Objective This study aimed to investigate the adolescent brain activation patterns in response to performance feedback (PF), social reward (SR) and monetary reward (MR) and their association with psychological factors. Methods Functional magnetic resonance imaging (fMRI) was performed while middle school boys (n=15) performed tests pertained to PF, SR and MR. The brain activation pattern in each condition was investigated, and the extent of brain activation in each of the three conditions was compared at once. Results The caudate and the dorsal prefrontal area were activated in all three conditions. Furthermore, the cuneus showed significantly greater activation in the PF condition than the SR or MR condition. And the self - related areas, such as the right precentral gyrus and paracenral lobule, were more activated in the SR condition than the PF or MR condition. The left middle frontal gyrus was more activated in the MR condition than the PF or SR condition. Conclusion Not only various reward stimuli but also feedback stimulus might commonly activate dorsal prefrontal and subcortical area in adolescents. Moreover, several different brain activation patterns were also observed in each condition. The results of this study could be applied to planning of learning and teaching strategy for adolescents in various ways.

The Genetic Factors Affecting Drinking Behaviors of Korean Young Adults with Variant Aldehyde Dehydrogenase 2 Genotype

Objective We determined whether aldehyde dehydrogenase 2 (ALDH2) activity alters the way in which drinking behaviors are affected by gene polymorphisms of other alcohol-metabolizing enzymes and serotonin-related proteins. Methods Through a follow-up survey with a cohort comprising 551 university freshmen over a period of 6 years, we examined the genetic factors affecting drinking behaviors. In 2000, drinking behaviors were assessed and tryptophan hydroxylase (TPH) and ALDH2 gene polymorphisms were determined. Drinking behaviors were repeated in 2006 (n=150), and the gene polymorphisms of ADH1B, ADH1C, CYP2E1, 5-HTR2A 1438A/G, and 5-HTR2A IVS2 were also determined. Results In 2000, the variant and wild-type ALDH2 groups exhibited little difference in terms of drinking frequency and problem drinking. Furthermore, some genotypes influenced only the variant group: ADH1B*2/*2 was associated with a lower drinking frequency, and CYP2E1 c2 allele was associated with an increased risk of problem drinking. In 2006, drinking frequency and risk of problem drinking were significantly lower in the variant group than in the wild-type group. However, the TPH AA genotype disturbed that difference, meaning that the subjects in the variant group had developed a similar level of risk of problem drinking to that in the wild-type group. Conclusion Korean university freshmen who were identified as a variant group drank as frequently as those in the wild-type group. For the subsequent 6 years they drank less frequently, thus decreasing the risk of problem drinking. However, that frequency drop was interrupted in those with gene polymorphisms such as ADH1B*1, CYP2E1 c2, and TPH A.

Autism and Beauty: Neural Correlates of Aesthetic Experiences in Autism Spectrum Disorder

Objectives: The purpose of this study was to investigate whether the neural activity of autism spectrum disorder (ASD) patients is different from that of normal individuals when performing aesthetic judgments. Methods: We recruited typical ASD patients without savant skills (ASD group, n=17) and healthy controls (HC group, n=19) for an functional magnetic resonance imaging study. All subjects were scanned while performing aesthetic judgment tasks on two kinds of artwork (magnificent landscape images and fractal images). Differences in brain activation between the two groups were assessed by contrasting neural activity during the tasks. Results: The aesthetic judgment score for all images was significantly lower in the ASD group than in the HC group. During the aesthetic judgment tasks, the ASD group showed less activation than the HC group in the anterior region of the superior frontal gyrus, and more activation in the temporoparietal area and insula, regardless of the type of images being judged. In addition, during the aesthetic judgment task for the fractal images, the ASD group exhibited greater neural activity in the amygdala and the posterior region of the middle/inferior temporal gyrus (Brodmann area 37) than the HC group. Conclusion: The results of this study suggest that the brain activation patterns associated with aesthetic experiences in ASD patients may differ from those of normal individuals.

Surface-Based Parameters of Brain Imaging in Male Patients with Alcohol Use Disorder

Objective The structural alteration of brain shown in patients with alcohol use disorder (AUD) can originate from both alcohol effects and genetic or developmental processes. We compared surface-based parameters of patients with AUD with healthy controls to prove the applicability of surface-based morphometry with head size correction and to determine the areas that were sensitive to brain alteration related to AUD. Methods Twenty-six abstinent male patients with AUD (alcohol group, mean abstinence=13.2 months) and twenty-eight age-matched healthy participants (control group) were recruited from an inpatient mental hospital and community. All participants underwent a 3T MRI scan. Surface-based parameters were determined by using FreeSurfer. Results Every surface-based parameter of the alcohol group was lower than the corresponding control group parameter. There were large group differences in the whole brain, grey and white matter volume, and the differences were more prominent after head size correction. Significant group differences were shown in cortical thicknesses in entire brain regions, especially in parietal, temporal and frontal areas. There were no significant group differences in surface areas, but group difference trends in surface areas of the frontal and parietal cortices were shown after head size correction. Conclusion Most of the surface-based parameters in alcohol group were altered because of incomplete recovery from chronic alcohol exposure and possibly genetic or developmental factors underlying the risk of AUD. Surface-based morphometry with controlling for head size is useful in comparing the volumetric parameters and the surface area to a lesser extent in alcohol-related brain alteration.