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With the advent of functional magnetic resonance imaging (fMRI), it is now possible to evaluate brain activation and to isolate structures that may be involved in social perception Hemispheric Effects While photographs have been frequently studied to examine a participant's interpretation of facial expressions, social communication occurs in a dynamic and fluid setting. The use of videotaped vignettes that convey social interactions may be sensitive to the participant's ability to understand context as well as changing situations. Using fMRI, increased activation was found in the frontal-cingulate-parietal connections when faces which were morphed from a neutral emotion to fear or anger were viewed Key Words Right hemisphere ؒ Social interactions ؒ Adults ؒ Functional magnetic resonance imaging Abstract Objective: The main purpose of this study was to evaluate whole-brain and hemispheric activation in normal adult volunteers to videos depicting positive and negative social encounters. There are few studies that have utilized dynamic social stimuli to evaluate brain activation. Method: Twenty young adults viewed videotaped vignettes during an functional magnetic resonance imaging procedure. The vignettes included positive and negative interaction scenes of social encounters. Results: Significant right greater than left activation for positive and negative conditions was found for the social interaction videos in the amygdaloid complex, the inferior frontal gyrus, the fusiform gyrus, and the temporal gyri (p ! 0.0001). Conclusion: These findings support the hypothesis that the regions of the right hemisphere are more active in the interpretation of social information processing than those regions in the left hemisphere. This study is a first step in understanding processing of dynamic stimuli using ecologically appropriate stimuli that approximate the realtime social processing that is appropriate for use with populations who experience significant social problems

Smaller splenium in children with nonverbal learning disability compared to controls, high functioning autism and ADHD

The current study investigated morphological differences in the corpus callosum in children ages 8 to 18 years old with nonverbal learning disability (NLD; n = 19), high-functioning autism (HFA; n = 23), predominantly inattentive ADHD (ADHD:PI; n = 23), and combined type ADHD (ADHD:C; n = 25), as well as those demonstrating typical development (n = 57). Midsagittal area of the corpus callosum and five midsagittal anterior-to-posterior corpus callosum segments were examined using magnetic resonance imaging. Controlling for midsagittal brain area and age, no group differences were found for total corpus callosum area. This finding indicates that higher functioning children on the autistic spectrum do not have smaller corpus callosi as has been found in previous research with heterogeneous samples. Following segmentation of the corpus callosum, the NLD group was observed to have significantly smaller splenia compared to all other groups. Smaller splenia in the NLD group was associated with lower WASI PIQ scores but not WASI VIQ scores. Children with HFA were observed to have larger midbody areas than children with NLD and neurotypically developing children. Children with HFA and NLD demonstrated behavioral symptoms of inattention and hyperactivity similar to the ADHD groups indicating that corpus callosum differences seen in the NLD and HFA groups are not related to these behaviors

A critical review of the literature on NLD as a developmental disorder

The extant research on nonverbal learning disability (NLD) was analyzed in this review. Studies were defined for use in the review as those that appeared in a peer-reviewed journal and included participants characterized as having NLD. Each study also needed to provide a statistical analysis of dependent variables. An a priori system was used to evaluate the quality of the research. Of the 88 publications found, 32 met criteria for inclusion in the review, with 6 meeting full criteria as strong studies. The diagnostic criteria used and the research findings are briefly discussed, as are proposed guidelines for future research