Optimized simultaneous ASL and BOLD functional imaging of the whole brain

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106990/1/jmri24273.pd

A Linear Structural Equation Model for Covert Verb Generation Based on Independent Component Analysis of fMRI Data from Children and Adolescents

Human language is a complex and protean cognitive ability. Young children, following well defined developmental patterns learn language rapidly and effortlessly producing full sentences by the age of 3 years. However, the language circuitry continues to undergo significant neuroplastic changes extending well into teenage years. Evidence suggests that the developing brain adheres to two rudimentary principles of functional organization: functional integration and functional specialization. At a neurobiological level, this distinction can be identified with progressive specialization or focalization reflecting consolidation and synaptic reinforcement of a network (Lenneberg, 1967; Muller et al., 1998; Berl et al., 2006). In this paper, we used group independent component analysis and linear structural equation modeling (McIntosh and Gonzalez-Lima, 1994; Karunanayaka et al., 2007) to tease out the developmental trajectories of the language circuitry based on fMRI data from 336 children ages 5–18 years performing a blocked, covert verb generation task. The results are analyzed and presented in the framework of theoretical models for neurocognitive brain development. This study highlights the advantages of combining both modular and connectionist approaches to cognitive functions; from a methodological perspective, it demonstrates the feasibility of combining data-driven and hypothesis driven techniques to investigate the developmental shifts in the semantic network

High-Tech Augmentative and Alternative Communication for Individuals with IDD and Complex Communication Needs: A Meta-Analysis (Variable Codes)

The attachment includes the operational definitions of the variable codes for the following article: The use of mobile technology is ubiquitous and is rapidly increasing in novel use. The use of mobile apps as augmentative and alternative communication (AAC) is rapidly expanding, both in the community and in the research literature. This article reports the social-communication outcome results of a meta-analysis of single-case experimental research on the use of high-tech AAC with individuals with intellectual and developmental disabilities, including autism spectrum disorder. Following inclusion determination, including excluding studies with poor design quality, raw data from 24 publications were extracted and included 89 A-B phase contrasts. Tau-U nonparametric, non-overlap effect size was used to aggregate the results across all studies for an omnibus and moderator analyses. Kendall’s S was calculated for confidence intervals, p-values, and standard error. The omnibus analysis indicated overall low to moderate positive effects on social-communication outcomes for high-tech AAC with people with IDD.The contents of this manuscript were developed under the Preparation of Leaders in Autism Across the Lifespan grant awarded by the U.S. Department of Education, Office of Special Education Programs (Grant No. H325D110046)

High-Tech Augmentative and Alternative Communication for Individuals with IDD and Complex Communication Needs: A Meta-Analysis (Search Terms)

Search Terms used in this manuscriptSearch Terms attached for the following paper: The use of mobile technology is ubiquitous and is rapidly increasing in novel use. The use of mobile apps as augmentative and alternative communication (AAC) is rapidly expanding, both in the community and in the research literature. This article reports the social-communication outcome results of a meta-analysis of single-case experimental research on the use of high-tech AAC with individuals with intellectual and developmental disabilities, including autism spectrum disorder. Following inclusion determination, including excluding studies with poor design quality, raw data from 24 publications were extracted and included 89 A-B phase contrasts. Tau-U nonparametric, non-overlap effect size was used to aggregate the results across all studies for an omnibus and moderator analyses. Kendall’s S was calculated for confidence intervals, p-values, and standard error. The omnibus analysis indicated overall low to moderate positive effects on social-communication outcomes for high-tech AAC with people with IDD.The contents of this manuscript were developed under the Preparation of Leaders in Autism Across the Lifespan grant awarded by the U.S. Department of Education, Office of Special Education Programs (Grant No. H325D110046)

Evidence that neurovascular coupling underlying the BOLD effect increases with age during childhood

Functional MRI using blood–oxygen‐level‐dependent (BOLD) imaging has provided unprecedented insights into the maturation of the human brain. Task‐based fMRI studies have shown BOLD signal increases with age during development (ages 5–18) for many cognitive domains such as language and executive function, while functional connectivity (resting‐state) fMRI studies investigating regionally synchronous BOLD fluctuations have revealed a developing functional organization of the brain from a local into a more distributed architecture. However, interpretation of these results is confounded by the fact that the BOLD signal is directly related to blood oxygenation driven by changes in blood flow and only indirectly related to neuronal activity, and may thus be affected by changing neuronal–vascular coupling. BOLD signal and cerebral blood flow (CBF) were measured simultaneously in a cohort of 113 typically developing awake participants ages 3–18 performing a narrative comprehension task. Using a novel voxelwise wild bootstrap analysis technique, an increased ratio of BOLD signal to relative CBF signal change with age (indicative of increased neuronal–vascular coupling) was seen in the middle temporal gyri and the left inferior frontal gyrus. Additionally, evidence of decreased relative oxygen metabolism (indicative of decreased neuronal activity) with age was found in the same regions. These findings raise concern that results of developmental BOLD studies cannot be unambiguously attributed to neuronal activity. Astrocytes and astrocytic processes may significantly affect the maturing functional architecture of the brain, consistent with recent research demonstrating a key role for astrocytes in mediating increased CBF following neuronal activity and for astrocyte processes in modulating synaptic connectivity. Hum Brain Mapp, 36:1–15, 2015 . © 2014 Wiley Periodicals, Inc .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110113/1/hbm22608.pd

High-Tech Augmentative and Alternative Communication for Individuals with IDD and Complex Communication Needs: A Meta-Analysis (Reference List)

The attached document lists the references for the following article: The use of mobile technology is ubiquitous and is rapidly increasing in novel use. The use of mobile apps as augmentative and alternative communication (AAC) is rapidly expanding, both in the community and in the research literature. This article reports the social-communication outcome results of a meta-analysis of single-case experimental research on the use of high-tech AAC with individuals with intellectual and developmental disabilities, including autism spectrum disorder. Following inclusion determination, including excluding studies with poor design quality, raw data from 24 publications were extracted and included 89 A-B phase contrasts. Tau-U nonparametric, non-overlap effect size was used to aggregate the results across all studies for an omnibus and moderator analyses. Kendall’s S was calculated for confidence intervals, p-values, and standard error. The omnibus analysis indicated overall low to moderate positive effects on social-communication outcomes for high-tech AAC with people with IDD.The contents of this manuscript were developed under the Preparation of Leaders in Autism Across the Lifespan grant awarded by the U.S. Department of Education, Office of Special Education Programs (Grant No. H325D110046)

High-Tech Augmentative and Alternative Communication for Individuals with IDD and Complex Communication Needs: A Meta-Analysis (Design Quality Review)

The attachment includes the description of the design quality review for the following paper: The use of mobile technology is ubiquitous and is rapidly increasing in novel use. The use of mobile apps as augmentative and alternative communication (AAC) is rapidly expanding, both in the community and in the research literature. This article reports the social-communication outcome results of a meta-analysis of single-case experimental research on the use of high-tech AAC with individuals with intellectual and developmental disabilities, including autism spectrum disorder. Following inclusion determination, including excluding studies with poor design quality, raw data from 24 publications were extracted and included 89 A-B phase contrasts. Tau-U nonparametric, non-overlap effect size was used to aggregate the results across all studies for an omnibus and moderator analyses. Kendall’s S was calculated for confidence intervals, p-values, and standard error. The omnibus analysis indicated overall low to moderate positive effects on social-communication outcomes for high-tech AAC with people with IDD.The contents of this manuscript were developed under the Preparation of Leaders in Autism Across the Lifespan grant awarded by the U.S. Department of Education, Office of Special Education Programs (Grant No. H325D110046)

Reading acceleration training changes brain circuitry in children with reading difficulties

Introduction: Dyslexia is characterized by slow, inaccurate reading. Previous studies have shown that the Reading Acceleration Program (RAP) improves reading speed and accuracy in children and adults with dyslexia and in typical readers across different orthographies. However, the effect of the RAP on the neural circuitry of reading has not been established. In the current study, we examined the effect of the RAP training on regions of interest in the neural circuitry for reading using a lexical decision task during fMRI in children with reading difficulties and typical readers. Methods: Children (8–12 years old) with reading difficulties and typical readers were studied before and after 4 weeks of training with the RAP in both groups. Results: In addition to improvements in oral and silent contextual reading speed, training-related gains were associated with increased activation of the left hemisphere in both children with reading difficulties and typical readers. However, only children with reading difficulties showed improvements in reading comprehension, which were associated with significant increases in right frontal lobe activation. Conclusions: Our results demonstrate differential effects of the RAP on neural circuits supporting reading in both children with reading difficulties and typical readers and suggest that the intervention may stimulate use of typical neural circuits for reading and engage compensatory pathways to support reading in the developing brain of children with reading difficulties

Interplay between morphology and frequency in lexical access: the case of the base frequency effect

A major issue in lexical processing concerns storage and access of lexical items. Here we make use of the base frequency effect to examine this. Specifically, reaction time to morphologically complex words (words made up of base and suffix, e.g., agree+able) typically reflects frequency of the base element (i.e., total frequency of all words in which agree appears) rather than surface word frequency (i.e., frequency of agreeable itself). We term these complex words decomposable. However, a class of words termed whole-word do not show such sensitivity to base frequency (e.g., serenity). Using an event-related MRI design, we exploited the fact that processing low-frequency words increases BOLD activity relative to high frequency ones, and examined effects of base frequency on brain activity for decomposable and whole-word items. Morphologically complex words, half high and half low base frequency, were compared to match high and low frequency simple monomorphemic words using a lexical decision task. Morphologically complex words increased activation in the left inferior frontal and left superior temporal cortices versus simple words. The only area to mirror the behavioral distinction between the decomposable and the whole-word types was the thalamus. Surprisingly, most frequency-sensitive areas failed to show base frequency effects. This variety of responses to frequency and word type across brain areas supports an integrative view of multiple variables during lexical access, rather than a dichotomy between memory-based access and on-line computation. Lexical access appears best captured as interplay of several neural processes with different sensitivities to various linguistic factors including frequency and morphological complexity

Greater Utilization of Neural-Circuits Related to Executive Functions is Associated with Better Reading: A Longitudinal fMRI Study Using the Verb Generation Task

Introduction: Reading is an acquired- developmental ability that relies on intact language and executive function skills. Verbal fluency tasks (such as verb generation) also engage language and executive function skills. Performance of such tasks matures with normal language development, and is independent of reading proficiency. In this longitudinal fMRI study, we aim to examine the association between maturation of neural circuits supporting both executive functions and language (assessed using verb generation) with reading proficiency achieved in adolescence with a focus on left lateralization typical for language proficiency. Methods: Normalized fMRI data from the verb generation task was collected from sixteen healthy children at ages 7, 11 and 17 years and was correlated with reading scores at 17 years of age. Lateralization indices were calculated in key language, reading and executive function-related regions in all age groups. Results: Typical development was associated with (i) increasingly left lateralized patterns in language regions (ii) more profound left lateralized activation for reading and executive function-related regions when correlating with reading scores, (iii) greater involvement of frontal and parietal regions (in older children), and of the anterior frontal cortex (in younger children). Conclusions: We suggest that reading and verb generation share mutual neural-circuits during development with major reliance on regions related to executive functions and reading. The results are discussed in the context of the dual-networks architecture model