CHARACTERIZING SENSORY PROCESSING IN AUTISM SPECTRUM DISORDERS

Rationale: Autism is a neurodevelopmental disorder with onset prior to the age of three years characterized by qualitative impairments in social interaction and communication skill, along with a restricted repetitive and stereotyped pattern of behavior, interests, and activities. In addition to these core diagnostic features, aberrant sensory responding has also been widely reported in the literature describing children and adolescents with autism spectrum disorders (ASD). Aberrant sensory processing has, however, been infrequently studied compared to communication and cognition in autism and existing studies have had multiple methodological deficiencies, especially with sampling procedures. Purpose. The purpose of this study is to describe patterns of sensory processing found in children with an ASD to test the relationship(s) of these patterns to diagnostic and developmental variables. Method. Retrospective data collection was used to collect developmental and sensory processing variables of 400 children with an ASD. Sensory processing abilities were measured by the SSP. Results. The majority of the sample (80.5%) had a diagnosis of autism. The average age of the sample was 49.58 months. The adaptive, social, language, and motor developmental variables were consistent with diagnostic patterns in that the children with Asperger Disorder demonstrated higher developmental levels than the children with autism and PDD-NOS. Eighty-nine percent of the sample demonstrated some degree of sensory processing dysfunction on the SSP Total Score with the greatest difficulties reported on the Underresponsive/Seeks Sensation, Auditory Filtering, and Tactile Sensitivity sections. Exploratory factor analysis identified 6 parsimonious factors: Low Energy/Weak, Tactile and Movement Sensitivity, Taste/Smell Sensitivity, Auditory and Visual Sensitivity, Sensory Seeking/Distractibility, and Hypo-responsivity. These factor variables contributed to explaining the differences in five of six developmental variables of the sample that are associated with the diagnosis of autism. Receptive language, adaptive and expressive language performance were significantly correlated with sensory processing factor scores. Conclusions. Together, the sensory processing findings noted in this study describe a pattern of dysfunctional sensory modulation. These findings have significant implications for intervention programs involving individuals with an ASD, given the potential impact of these findings on a childs ability to maintain active engagement

Planning for End-Of-Life Satellite Disposal; The Story of a High Strain Composite Tip-Rolled De-Orbit Sail

In Q4 of 2017, Roccor of Longmont, Colorado was approached by an ESPA class spacecraft provider with the request to deliver a de-orbit sail within a six-month period. The 140kg spacecraft was to be placed in a circular ~750km, high inclination orbit and needed to deploy a drag device at the end-of-life with a surface area greater than 4m2. After a series of concept iterations with the customer, dual rectangular tip-roll sails were selected, each supported by a deployable High Strain Composite (HSC) boom and offset 45º from the spacecraft’s structure maximizing the cross-sectional area and aerodynamic stability. The rectangular sails, each measuring 4m x 0.5m, are named Roll-Out Composite, FCC Approved Life Limiting Deorbit Devices otherwise known as ROC-FALL. Their low-cost design boasts a simple and robust deployment mechanism utilizing few machined parts that is easily resettable to allow multiple deployment-cycle tests for mission assurance. This paper first provides a broad overview of the space debris problem and a summary of current technologies that are known for end-of-life satellite disposal. This paper then details the ROC-FALL design, and chronicles the recent flight build and lessons learned

Planning for End-Of-Life Satellite Disposal; The Story of a High Strain Composite Tip-Rolled De-Orbit Sail

In Q4 of 2017, Roccor of Longmont, Colorado was approached by an ESPA class spacecraft provider with the request to deliver a de-orbit sail within a six-month period. The 140kg spacecraft was to be placed in a circular ~750km, high inclination orbit and needed to deploy a drag device at the end-of-life with a surface area greater than 4m2. After a series of concept iterations with the customer, dual rectangular tip-roll sails were selected, each supported by a deployable High Strain Composite (HSC) boom and offset 45º from the spacecraft’s structure maximizing the cross-sectional area and aerodynamic stability. The rectangular sails, each measuring 4m x 0.5m, are named Roll-Out Composite, FCC Approved Life Limiting Deorbit Devices otherwise known as ROC-FALL. Their low-cost design boasts a simple and robust deployment mechanism utilizing few machined parts that is easily resettable to allow multiple deployment-cycle tests for mission assurance. This paper first provides a broad overview of the space debris problem and a summary of current technologies that are known for end-of-life satellite disposal. This paper then details the ROC-FALL design, and chronicles the recent flight build and lessons learned

Diffusion tensor tractography in children with sensory processing disorder: potentials for devising machine learning classifiers

The “sensory processing disorder” (SPD) refers to brain's inability to organize sensory input for appropriate use. In this study, we determined the diffusion tensor imaging (DTI) microstructural and connectivity correlates of SPD, and apply machine learning algorithms for identification of children with SPD based on DTI/tractography metrics. A total of 44 children with SPD and 41 typically developing children (TDC) were prospectively recruited and scanned. In addition to fractional anisotropy (FA), mean diffusivity (MD), and radial diffusivity (RD), we applied probabilistic tractography to generate edge density (ED) and track density (TD) from DTI maps. For identification of children with SPD, accurate classification rates from a combination of DTI microstructural (FA, MD, AD, and RD), connectivity (TD) and connectomic (ED) metrics with different machine learning algorithms – including naïve Bayes, random forest, support vector machine, and neural networks – were determined. In voxel-wise analysis, children with SPD had lower FA, ED, and TD but higher MD and RD compared to TDC – predominantly in posterior white matter tracts including posterior corona radiata, posterior thalamic radiation, and posterior body and splenium of corpus callosum. In stepwise penalized logistic regression, the only independent variable distinguishing children with SPD from TDC was the average TD in the splenium (p < 0.001). Among different combinations of machine learning algorithms and DTI/connectivity metrics, random forest models using tract-based TD yielded the highest accuracy in classification of SPD – 77.5% accuracy, 73.8% sensitivity, and 81.6% specificity. Our findings demonstrate impaired microstructural and connectivity/connectomic integrity in children with SPD, predominantly in posterior white matter tracts, and with reduced TD of the splenium of corpus callosum as the most distinctive pattern. Applying machine learning algorithms, these connectivity metrics can be used to devise novel imaging biomarkers for neurodevelopmental disorders

Neurobiological foundations of multisensory integration in people with autism spectrum disorders: the role of the medial prefrontal cortex.

This review aims to relate the sensory processing problems in people with autism spectrum disorders (ASD), especially multisensory integration (MSI), to the role of the medial prefrontal cortex (mPFC) by exploring neuroanatomical findings; brain connectivity and Default Network (DN); global or locally directed attention; and temporal multisensory binding. The mPFC is part of the brain¿s DN, which is deactivated when attention is focused on a particular task and activated on rest when spontaneous cognition emerges. In those with ASD, it is hypoactive and the higher the social impairment the greater the atypical activity. With an immature DN, cross-modal integration is impaired, resulting in a collection of disconnected fragments instead of a coherent global perception. The deficit in MSI may lie in the temporal synchronization of neural networks. The time interval in which the stimulation of one sensory channel could influence another would be higher, preventing integration in the typical shorter time range. Thus, the underconnectivity between distant brain areas would be involved in top-down information processes (relying on global integration of data from different sources) and would enhance low level perception processes such as over focused attention to s

Construction and validation of an developmental profile assessment tool for children with autistic spectrum disorder

Nos últimos anos a investigação tem dado particular relevância às alterações do Processamento Sensorial nas crianças com perturbações do espectro do autismo (PEA) e a literatura refere que entre 42% a 88% das crianças com PEA apresentam este tipo de disfunção. Nesta linha foi definido um projeto de investigação centrado na construção de uma escala que avalie a tradicional tríade que caracteriza as crianças com PEA (Interação, Comunicação e Comportamento e interesses repetitivos e estereotipados), enriquecida pela inclusão de um novo domínio: o Processamento Sensorial. Com a construção e validação desta escala pretendemos que pais e profissionais utilizem colaborativamente um instrumento de avaliação da intervenção que lhes permita monitorizar o processo de apoio e adequar as suas práticas. Neste artigo descrevemos os procedimentos e os resultados das sucessivas fases de construção do instrumento, desde as análises iniciais mais qualitativas até aos estudos centrados na análise quantitativa dos itens.During the last few years, research has focused on changes in Sensory Processing in children with Autistic Spectrum Disorder (ASD). As a result, literature has shown that between 42% and 88% of children with ASD present this type of disorder. Based on these findings, a research project was designed centring on the construction of a tool to assess the traditional triad that characterizes children with ASD (Interaction, Communication and Behaviour and Repetitive and Stereotyped Interests), to which was added a new domain: Sensory Processing. By constructing and validating this assessment tool, the intention is for parents and professionals to collaboratively apply this intervention assessment instrument in order to monitor the support process and adapt their practices. In this paper, we describe procedures and results of the successive stages entailed in constructing this instrument, from the first primarily qualitative analyses up to the studies centred on the quantitative item analysis.Fundação para a Ciência e Tecnologia (FCT)ABPEE - Associação Brasileira de Pesquisadores em Educação EspecialConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CAPESMinistério da Educação - BrasilMinistério da Ciência e da Tecnologia - BrasilGoverno Federal - Brasi

How Sensory Experiences Affect Adolescents with an Autistic Spectrum Condition within the Classroom

Sensory processing difficulties are consistently reported amongst individuals with an autistic spectrum condition (ASC); these have a significant impact on daily functioning. Evidence in this area comes from observer reports and first-hand accounts; both have limitations. The current study used the Adolescent/Adult Sensory Profile (AASP; Brown and Dunn in The Adolescent/Adult Sensory Profile: self questionnaire. Pearson, 2002a), and a qualitative questionnaire to investigate sensory issues in school children with ASC. The AASP found that the participants’ mean scores were outside normal parameters. Participants reported difficulties in at least one sensory domain, with hearing affecting them the most. Content analysis revealed sensory sensitivity to affect the participant’s learning and that sensory experiences were largely negative. Results suggest that schools need to create sensory profiles for each individual with ASC

Sensorimotor Difficulties Are Associated with the Severity of Autism Spectrum Conditions

Present diagnostic criteria for autism spectrum conditions (ASC) include social communication and interaction difficulties, repetitive behaviour and movement, and atypical sensory responsivity. Few studies have explored the influence of motor coordination and sensory responsivity on severity of ASC symptoms. In the current study, we explore whether sensory responsivity and motor coordination differences can account for the severity of autistic behaviours in children with ASC. 36 children took part: 18 (13 male, 5 female) with ASC (ages 7-16: mean age 9.93 years) and 18 (7 male, 11 female) typically developing (TD) children (ages 6-12; mean age 9.16 years). Both groups completed a battery of assessments that included motor coordination, sensory responsivity, receptive language, non-verbal reasoning and social communication measures Children with ASC also completed the Autism Diagnostic Observation Schedule and Autism Diagnostic Interview – Revised.. Results showed that children with ASC scored significantly lower on receptive language, coordination and sensory responsivity and a sensorimotor subscale, Modulation of Activity (MoA) compared to the TD group. In the ASC group, MoA significantly predicted ASC severity across all ASC measures; receptive language and sensory responsivity significantly predicted parental reported autism measures; and coordination significantly predicted examiner observed reported scores. Additionally, specific associations were found between the somatosensory perceptive modalities and ASC severity. The results show that sensorimotor skills are associated with severity of ASC symptoms; furthering the need to research sensorimotor integration in ASC and also implying that diagnosis of ASC should also include the assessment of both coordination deficit and atypical sensory responsivity

A Close Eye on the Eagle-Eyed Visual Acuity Hypothesis of Autism

Autism spectrum disorders (ASD) have been associated with sensory hypersensitivity. A recent study reported visual acuity (VA) in ASD in the region reported for birds of prey. The validity of the results was subsequently doubted. This study examined VA in 34 individuals with ASD, 16 with schizophrenia (SCH), and 26 typically developing (TYP). Participants with ASD did not show higher VA than those with SCH and TYP. There were no substantial correlations of VA with clinical severity in ASD or SCH. This study could not confirm the eagle-eyed acuity hypothesis of ASD, or find evidence for a connection of VA and clinical phenotypes. Research needs to further address the origins and circumstances associated with altered sensory or perceptual processing in ASD