12 research outputs found
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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 Ř’ Social interactions Ř’ Adults Ř’ 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
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The corpus callosum and reading : an MRI volumetric study
textResearchers have long been interested in the role of the corpus callosum in reading disorder, but existing studies have yielded inconsistent results. Some have found larger corpus callosa in those with reading disorder, others have found smaller corpus callosa, and some have found no differences in the corpus callosa of persons with and without reading disability. Some possible problems with past studies include failure to control for whole brain size, intelligence, gender, lateral dominance, and the presence of other syndromes such as Attention Deficit Hyperactivity Disorder. The current study is an examination of the corpus callosum in 68 readers nested in 24 families. Data were centered around the family mean so that the variance within families could be determined. Corpus callosum volumes were measured and controlled for whole brain volume, intelligence, and gender. A series of regressions were used to determine whether the volume of the corpus callosum significantly contributed to the variance in oral reading, phonological processing, and rapid naming. The midsagittal slice was segmented into fifths, and similar regressions were performed. A logistic regression was used to determine whether variation in corpus callosum volume could predict RD and no RD group membership. Finally, left and right volumes were compared and a correlation between corpus callosum volume and area at the midsagittal slice were conducted. Results suggest that better readers within families have larger corpus callosum areas in the midsagittal slice at the midbody. Better phonological processors within families had smaller corpus callosum volumes, but a problem with restricted range for phonological processing scores renders this finding unreliable. Rapid naming scores appear to be unrelated to the corpus callosum in this sample. Differences in the corpus callosum are not robust enough to predict diagnostic group and there appears to be no differences between left and right hemisphere volumes of the corpus callosum. Measurements of area at the midsagittal slice are highly correlated with the volumetric measurements suggesting that for subsequent studies, area at the midsagittal slice may be sufficient.Educational Psycholog
An updated review of neuroimaging studies of children and adolescents with perinatally acquired HIV
A recent review of neuroimaging studies related to perinatally acquired human immunodeficiency virus (HIV) infection by Hoare and colleagues (Metabolic Brain Disease 29:221–229, 2014) included studies published between 1995 and 2012, with all but two studies being published in or before 2006. Although the review synthesized the extant research available at the time, the findings may not be relevant to the current population of children and adolescents who are HIV positive due to more recent advances in antiretroviral medication and new medication guidelines. As such, the purpose of this paper was to extend the findings of Hoare and colleagues by reviewing the imaging literature that has been published since 2012 and to compare the more recent studies to the earlier ones. The results were that 11 articles met criteria for inclusion in this review. The majority of studies were cross-sectional and analyzed MRI data.. Samples included children and adolescents of nearly all ages. Studies differed widely on the inclusion and reporting of clinical variables. Imaging was focused primarily on white matter, and white matter issues such as lesions, poor tract integrity, and reduced volume were found in samples of children and adolescents of various age ranges. Two studies compared the cognitive functioning of children with HIV to controls, and both found that children with HIV perform more poorly than their non-infected peers on various cognitive tasks. Based on the findings of this review, recommendations for future imaging research are made
Nonverbal Learning Disabilities
Increasing numbers of children and adolescents are being diagnosed with nonverbal learning disabilities (NLD), yet clinicians and educators have few scientific resources to guide assessment and intervention. This book presents up-to-date knowledge on the nature of NLD and how to differentiate it from DSM-5 disorders such as autism spectrum disorder and developmental coordination disorder. Effective strategies for helping K-12 students and their families address the challenges of NLD in and outside of the classroom are illustrated with vivid case material. The authors thoughtfully consider controversies surrounding NLD, discuss why the diagnosis is not included in the current DSM and ICD classification systems, and identify important directions for future research
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
Confirmatory Factor Structure of the Kaufman Assessment Battery for Children-Second Edition: Consistency With Cattell-Horn-Carroll Theory
The Kaufman Assessment Battery for Children-Second Edition (KABC-II) is a departure from the original KABC in that it allows for interpretation via two theoretical models of intelligence. This study had two purposes: to determine whether the KABC-II measures the same constructs across ages and to investigate whether those constructs are consistent with Cattell-Horn-Carroll (CHC) theory. Multiple-sample analyses were used to test for equality of the variance-covariance matrices across the 3- to 18-year-old sample. Higher-order confirmatory factor analyses were used to compare the KABC-II model with rival CHC models for children ages 6 to 18. Results show that the KABC-II measures the same constructs across all ages. The KABC-II factor structure for school-age children is aligned closely with five broad abilities from CHC theory, although some inconsistencies were found. Models without time bonuses fit better than those with time bonuses. The results provide support for the construct validity of the KABC-II. Additional research is needed to more completely understand the measurement of fluid reasoning and the role of time bonuses on some tasks. © 2007 American Psychological Association
Higher Order, Multisample, Confirmatory Factor Analysis Of The Wechsler Intelligence Scale For Children - Fourth Edition: What Does It Measure?
The recently published fourth edition of the Wechsler Intelligence Scale for Children (WISC-IV) represents a considerable departure from previous versions of the scale. The structure of the instrument has changed, and some subtests have been added and others deleted. The technical manual for the WISC-IV provided evidence supporting this new structure, but questions about consistency of measurement across ages and the nature of the constructs measured by the test remain. This research was designed to determine whether the WISC-IV measures the same constructs across its 11-year age span and to explicate the nature of those constructs. The results suggest that the WISC-IV indeed measures consistent constructs across ages. The scoring structure of the test was not supported in these analyses, however. Comparison of theory-derived alternative models suggests a model more closely aligned with CattellHom-Carroll theory provides a better fit to the WISC-IV standardization data than does the existing WISC-IV structure. In particular, it appears that the WISC-IV measures crystallized ability (Gc), visual processing (Gv), fluid reasoning (Gf), short-term memory (Gsm), and processing speed (Gs); some abilities are well measured, others are not. We recommend that users regroup the Perceptual Reasoning tests, and Arithmetic, to better reflect the constructs measured by the WISC-IV. Specific suggestions are also provided for interpretation of WISC-IV scores. Copyright 2006 by the National Association of School Psychologists