Abnormal Brain Activity in Social Reward Learning in Children with Autism Spectrum Disorder: An fMRI Study

PURPOSE: We aimed to determine whether Autism Spectrum Disorder (ASD) would show neural abnormality of the social reward system using functional MRI (fMRI). MATERIALS AND METHODS: 27 ASDs and 12 typically developing controls (TDCs) participated in this study. The social reward task was developed, and all participants performed the task during fMRI scanning. RESULTS: ASDs and TDCs with a social reward learning effect were selected on the basis of behavior data. We found significant differences in brain activation between the ASDs and TDCs showing a social reward learning effect. Compared with the TDCs, the ASDs showed reduced activity in the right dorsolateral prefrontal cortex, right orbitofrontal cortex, right parietal lobe, and occipital lobe; however, they showed increased activity in the right parahippocampal gyrus and superior temporal gyrus. CONCLUSION: These findings suggest that there might be neural abnormality of the social reward learning system of ASDs. Although this study has several potential limitations, it presents novel findings in the different neural mechanisms of social reward learning in children with ASD and a possible useful biomarker of high-functioning ASDs.

Abnormal Activation of the Social Brain Network in Children with Autism Spectrum Disorder: An fMRI Study

OBJECTIVE: The aim of this study is to investigate abnormal findings of social brain network in Korean children with autism spectrum disorder (ASD) compared with typically developing children (TDC). METHODS: Functional magnetic resonance imaging (fMRI) was performed to examine brain activations during the processing of emotional faces (happy, fearful, and neutral) in 17 children with ASD, 24 TDC. RESULTS: When emotional face stimuli were given to children with ASD, various areas of the social brain relevant to social cognition showed reduced activation. Specifically, ASD children exhibited less activation in the right amygdala (AMY), right superior temporal sulcus (STS) and right inferior frontal gyrus (IFG) than TDC group when fearful faces were shown. Activation of left insular cortex and right IFG in response to happy faces was less in the ASD group. Similar findings were also found in left superior insular gyrus and right insula in case of neutral stimulation. CONCLUSION: These findings suggest that children with ASD have different processing of social and emotional experience at the neural level. In other words, the deficit of social cognition in ASD could be explained by the deterioration of the capacity for visual analysis of emotional faces, the subsequent inner imitation through mirror neuron system (MNS), and the ability to transmit it to the limbic system and to process the transmitted emotion.

An fMRI Study Regarding the 'Theory of Mind' in Korean Schizophrenic Patients Using a First Order False Belief Task / 신경정신의학

OBJECTIVES: The aim of this study was to investigate brain activation during a Korean language-based 'theory of mind (TOM)' task and fMRI in Korean schizophrenic patients. METHODS: Fourteen Korean schizophrenic patients and 15 normal controls participated in this study. For all participants, several clinical states and psychosocial functions were evaluated. The subjects were then scanned while performing Korean language-based fMRI tasks. The tasks were comprised of conditions-first order false belief (TOM task), physical causality, and unrelated situations. Imaging data were analyzed using SPM2 software (uncorrected p<0.005, extent threshold kappa=10). RESULTS: 1) Compared with the control group, the patient group showed significantly poorer performance on the TOM task, and no significant correlation between TOM and empathic abilitiesy. 2) In the patient group, there were no significantly activated brain regions associated with the TOM task as compared to the physical causality task. With respect to between-group differences, the patient group showed significantly less activation of the left medial frontal region (primarily BA 8) and signifcantly different activation of the left precuneus (BA 7) associated with the TOM task. CONCLUSION: These results suggest that Korean schizophreniac patients show different brain activity associated with TOM functions, especially with respect to the Korean language-based first order false belief tasks.

Functional MRI Study on Perceiving Orthographic Structure and Simplified Semantic Pictures

The different perceiving patterns of each picture, alphabetic words and Chinese characters, were widely investigated psychophysically. The more precise localisation can be done in terms of brain activity using functional image technique such as PET and fMRI recently. Until now, there was no fMRI study to make direct comparison between perception of single Chinese character and simplified pictures (pictograph). We have made direct comparison of these two components using modern magnetic resonance techniques. We cannot confirm the right hemispheric dominance for perception of single Chinese character and pictographs. These two kinds of perceiving pattern can be underlying different mechanism.