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To identify valid measures of vocal development in young children with autism spectrum disorder in the early stages of language learning, we evaluated the convergent validity, divergent validity, and sensitivity to change (across 12 months) of two measures of vocal communication and two measures of vocal complexity through conventional coding of communication samples. Participants included 87 children with autism spectrum disorder (M = 23.42 months at entry). All four vocal variables demonstrated consistent evidence of convergent validity, divergent validity, and sensitivity to change with large effect sizes for convergent validity and sensitivity to change. The results highlight the value of measuring vocal communication and vocal complexity in future studies.
Purpose The purpose of this study was to evaluate if higher quantity, diversity, and grammatical informativeness of verb phrases in parent follow-in utterances (i.e., utterances that mapped onto child attentional leads) were significantly related to later expressive verb vocabulary in children with autism spectrum disorder (ASD). Method We examined these associations in a sample of 31 toddlers with ASD and their parents in a longitudinal correlational study. Key aspects of parents' verb input were measured in 2 video-recorded 15-min parent-child free-play sessions. Child expressive verb vocabulary was measured using parent report. Results An aggregate variable composed of the quantity, diversity, and grammatical informativeness of parent verb input in follow-in utterances across the 2 parent-child sessions strongly and positively predicted later child expressive verb vocabulary, total R = .25, even when early child expressive verb vocabulary was controlled, R change = .17. Parent follow-in utterances without verbs were not significantly related to later child expressive verb vocabulary, R = .001. Conclusions These correlational findings are initial steps toward developing a knowledge base for how strong verb vocabulary skills might be facilitated in children with ASD.
Atypical responses to tactile stimulation have been linked to core domains of dysfunction in individuals with autism spectrum disorder (ASD) and phenotypic traits associated with ASD in neurotypical individuals. We investigated (a) the extent to which two psychophysically derived measures of tactile sensitivity-detection threshold and dynamic range-relate to traits associated with ASD and (b) whether those relations vary according to the presence of self-reported sensory hypersensitivities in neurotypical individuals. A narrow dynamic range was associated with increased autism-related traits in individuals who reported greater sensory hypersensitivity. In contrast, in individuals less prone to sensory hypersensitivity, a narrow dynamic range was associated with reduced autism-related traits. Findings highlight the potential importance of considering dynamic psychophysical metrics in future studies.
The relation between caregiver follow-in utterances with verbs presented in different states of dyadic engagement and later child expressive verb vocabulary in children with autism spectrum disorder (ASD) was examined in 29 toddlers with ASD and their caregivers. Caregiver verb input in follow-in utterances presented during higher order supported joint engagement (HSJE) accounted for a significant, large amount of variance in later child verb vocabulary; R= .26. This relation remained significant when controlling for early verb vocabulary or verb input in lower support engagement states. Other types of talk in follow-in utterances in HSJE did not correlate with later verb vocabulary. These findings are an important step towards identifying interactional contexts that facilitate verb learning in children with ASD.
The human dopamine (DA) transporter (hDAT) mediates clearance of DA. Genetic variants in hDAT have been associated with DA dysfunction, a complication associated with several brain disorders, including autism spectrum disorder (ASD). Here, we investigated the structural and behavioral bases of an ASD-associated in-frame deletion in hDAT at N336 (∆N336). We uncovered that the deletion promoted a previously unobserved conformation of the intracellular gate of the transporter, likely representing the rate-limiting step of the transport process. It is defined by a "half-open and inward-facing" state (HOIF) of the intracellular gate that is stabilized by a network of interactions conserved phylogenetically, as we demonstrated in hDAT by Rosetta molecular modeling and fine-grained simulations, as well as in its bacterial homolog leucine transporter by electron paramagnetic resonance analysis and X-ray crystallography. The stabilization of the HOIF state is associated both with DA dysfunctions demonstrated in isolated brains of expressing hDAT ∆N336 and with abnormal behaviors observed at high-time resolution. These flies display increased fear, impaired social interactions, and locomotion traits we associate with DA dysfunction and the HOIF state. Together, our results describe how a genetic variation causes DA dysfunction and abnormal behaviors by stabilizing a HOIF state of the transporter.
Obtaining stable estimates of caregiver-child joint engagement states is of interest for researchers who study development and early intervention in young children with autism spectrum disorder (ASD). However, studies to date have offered little guidance on the numbers of sessions and coders necessary to obtain sufficiently stable estimates of these constructs. We used procedures derived from G theory to carry out a generalizability study, in which we partitioned error variance between two facets of our system for measuring joint engagement states: session and coder. A decision study was then conducted to determine the number of sessions and coders required to obtain g coefficients of 0.80, an a priori threshold set for acceptable stability. This process was conducted separately for 10 infant siblings of children with ASD (Sibs-ASD) and 10 infants whose older sibling did not have ASD (Sibs-TD), and for two different joint engagement states; lower- and higher-order supported joint engagement (LSJE and HSJE, respectively). Results indicated that, in the Sibs-ASD group, four sessions and one coder was required to obtain acceptably stable estimates for HSJE; only one session and one coder were required for LSJE. In the Sibs-TD group, two sessions and one coder were required for HSJE; seven sessions and two coders were required for LSJE. Implications for measurement in future research are discussed. Autism Res 2019, 12: 495-504 © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: This study offers guidance for researchers who measure joint engagement between caregivers and infants who have an older sibling with ASD, and who have older siblings who are TD.
© 2019 International Society for Autism Research, Wiley Periodicals, Inc.
An ever-growing literature has aimed to determine how individuals with autism spectrum disorder (ASD) differ from their typically developing (TD) peers on measures of multisensory integration (MSI) and to ascertain the degree to which differences in MSI are associated with the broad range of symptoms associated with ASD. Findings, however, have been highly variable across the studies carried out to date. The present work systematically reviews and quantitatively synthesizes the large literature on audiovisual MSI in individuals with ASD to evaluate the cumulative evidence for (a) group differences between individuals with ASD and TD peers, (b) correlations between MSI and autism symptoms in individuals with ASD and (c) study level factors that may moderate findings (i.e., explain differential effects) observed across studies. To identify eligible studies, a comprehensive search strategy was employed using the ProQuest search engine, PubMed database, forwards and backwards citation searches, direct author contact, and hand-searching of select conference proceedings. A significant between-group difference in MSI was evident in the literature, with individuals with ASD demonstrating worse audiovisual integration on average across studies compared to TD controls. This effect was moderated by mean participant age, such that between-group differences were more pronounced in younger samples. The mean correlation between MSI and autism and related symptomatology was also significant, indicating that increased audiovisual integration in individuals with ASD is associated with better language/communication abilities and/or reduced autism symptom severity in the extant literature. This effect was moderated by whether the stimuli were linguistic versus non-linguistic in nature, such that correlation magnitudes tended to be significantly greater when linguistic stimuli were utilized in the measure of MSI. Limitations and future directions for primary and meta-analytic research are discussed.
Copyright © 2018 Elsevier Ltd. All rights reserved.
Research shows that children with autism spectrum disorder (ASD) differ in their behavioral patterns of responding to sensory stimuli (i.e., sensory responsiveness) and in various other aspects of sensory functioning relative to typical peers. This study explored relations between measures of sensory responsiveness and multisensory speech perception and integration in children with and without ASD. Participants were 8-17 year old children, 18 with ASD and 18 matched typically developing controls. Participants completed a psychophysical speech perception task, and parents reported on children's sensory responsiveness. Psychophysical measures (e.g., audiovisual accuracy, temporal binding window) were associated with patterns of sensory responsiveness (e.g., hyporesponsiveness, sensory seeking). Results indicate that differences in multisensory speech perception and integration covary with atypical patterns of sensory responsiveness.
The Short Sensory Profile (SSP) is one of the most commonly used measures of sensory features in children with autism spectrum disorder (ASD), but psychometric studies in this population are limited. Using confirmatory factor analysis, we evaluated the structural validity of the SSP subscales in ASD children. Confirmatory factor models exhibited poor fit, and a follow-up exploratory factor analysis suggested a 9-factor structure that only replicated three of the seven original subscales. Secondary analyses suggest that while reliable, the SSP total score is substantially biased by individual differences on dimensions other than the general factor. Overall, our findings discourage the use of the SSP total score and most subscale scores in children with ASD. Implications for future research are discussed.
Sensory processing differences, including responses to auditory, visual, and tactile stimuli, are ideal targets for early detection of neurodevelopmental risks, such as autism spectrum disorder. However, most existing studies focus on the audiovisual paradigm and ignore the sense of touch. In this paper, we present a multisensory delivery system that can deliver audio, visual, and tactile stimuli in a controlled manner and capture peripheral physiological, eye gaze, and electroencephalographic response data. The novelty of the system is the ability to provide affective touch. In particular, we have developed a tactile stimulation device that delivers tactile stimuli to infants with precisely controlled brush stroking speed and force on the skin. A usability study of 10 3-20 month-old infants was conducted to investigate the tolerability and feasibility of the system. Results have shown that the system is well tolerated by infants and all the data were collected robustly. This paper paves the way for future studies charting the sensory response trajectories in infancy.