Sensory Processing in Autism: A Review of Neurophysiologic Findings

Department of Neurology, University of California, San Francisco, California 94143, USA.
Pediatric Research (Impact Factor: 2.31). 02/2011; 69(5 Pt 2):48R-54R. DOI: 10.1203/PDR.0b013e3182130c54
Source: PubMed


Atypical sensory-based behaviors are a ubiquitous feature of autism spectrum disorders (ASDs). In this article, we review the neural underpinnings of sensory processing in autism by reviewing the literature on neurophysiological responses to auditory, tactile, and visual stimuli in autistic individuals. We review studies of unimodal sensory processing and multisensory integration that use a variety of neuroimaging techniques, including electroencephalography (EEG), magnetoencephalography (MEG), and functional MRI. We then explore the impact of covert and overt attention on sensory processing. With additional characterization, neurophysiologic profiles of sensory processing in ASD may serve as valuable biomarkers for diagnosis and monitoring of therapeutic interventions for autism and reveal potential strategies and target brain regions for therapeutic interventions.

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Available from: Leighton Hinkley, Jul 10, 2014
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    • "Anatomical ROIs comprised: the anterior cingulate cortex (ACC) [Amaral et al., 2008; Dichter et al., 2009; Oblak et al., 2010; Thakkar et al., 2008], the caudate [Amaral et al., 2008; Langen et al., 2007; Sears et al., 1999], and the fusiform gyrus (FFG) [Amaral et al., 2008; Kwon et al., 2004; Oblak et al., 2010; van Kooten et al., 2008]. Functional ROIs were based on the neurosynth search terms " emotion regulation " (161 studies; k 5 404 voxels) [Mazefsky et al., 2013; Samson et al., 2012], " mentalizing " (124 studies; k 5 1,866 voxels) [Baron-Cohen, 1995; Frith, 2001], and " sensory " (949 studies; k 5 725 voxels) [Leekam et al., 2007; Marco et al., 2011; Tomchek and Dunn, 2007]. "
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    ABSTRACT: In humans, both language and fine motor skills are associated with left-hemisphere specialization, whereas visuospatial skills are associated with right-hemisphere specialization. Individuals with autism spectrum conditions (ASC) show a profile of deficits and strengths that involves these lateralized cognitive functions. Here we test the hypothesis that regions implicated in these functions are atypically rightward lateralized in individuals with ASC and, that such atypicality is associated with functional performance. Participants included 67 male, right-handed adults with ASC and 69 age- and IQ-matched neurotypical males. We assessed group differences in structural asymmetries in cortical regions of interest with voxel-based analysis of grey matter volumes, followed by correlational analyses with measures of language, motor and visuospatial skills. We found stronger rightward lateralization within the inferior parietal lobule and reduced leftward lateralization extending along the auditory cortex comprising the planum temporale, Heschl's gyrus, posterior supramarginal gyrus, and parietal operculum, which was more pronounced in ASC individuals with delayed language onset compared to those without. Planned correlational analyses showed that for individuals with ASC, reduced leftward asymmetry in the auditory region was associated with more childhood social reciprocity difficulties. We conclude that atypical cerebral structural asymmetry is a potential candidate neurophenotype of ASC. Hum Brain Mapp, 2015. © 2015 Wiley Periodicals, Inc.
    Human Brain Mapping 10/2015; DOI:10.1002/hbm.23023 · 5.97 Impact Factor
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    • "As many of these abnormalities have been replicated in samples of first-degree relatives of individuals with schizophrenia (Bedwell et al., 2003; Green et al., 2006; Bakanidze et al., 2013; Sponheim et al., 2013) and nonpsychiatric schizotypy (Aichert et al., 2012; Bedwell et al., 2013), they may reflect underlying vulnerability for schizophrenia and serve as useful biomarkers. However, visual processing deficits have also been reported in other psychiatric disorders, including autism (Marco et al., 2011), bipolar disorder (Yeap et al., 2009), and unipolar depression (Normann et al., 2007), and therefore may not be specific to the diagnostic category of schizophrenia. Existing studies on these relationships have primarily examined visual processing deficits within a single diagnostic category or construct, as compared to nonpsychiatric controls. "
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    ABSTRACT: Visual processing abnormalities have been reported across a range of psychotic and mood disorders, but are typically examined within a particular disorder. The current study used a novel transdiagnostic approach to examine diagnostic classes, clinician-rated current symptoms, and self-reported personality traits in relation to visual processing abnormalities. We examined transient visual-evoked potentials (VEPs) from 48 adults (56% female), representing a wide range of psychotic and mood disorders, as well as individuals with no history of psychiatric disorder. Stimuli were low contrast check arrays presented on green and red backgrounds. Pairwise comparisons between individuals with schizophrenia-spectrum disorders (SSD), chronic mood disorders (CMD), and nonpsychiatric controls (NC) revealed no overall differences for either P1 or N1 amplitude. However, there was a significant interaction with the color background in which the NC group showed a significant increase in P1 amplitude to the red, vs. green, background, while the SSD group showed no change. This was related to an increase in social anhedonia and general negative symptoms. Stepwise regressions across the entire sample revealed that individuals with greater apathy and/or eccentric behavior had a reduced P1 amplitude. These relationships provide clues for uncovering the underlying causal pathology for these transdiagnostic symptoms.
    09/2015; DOI:10.1016/j.psychres.2015.09.004
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    • "communication and interaction, and by restricted interests and repetitive behaviors (American Psychiatric Association, 2013). Over the last few decades, interest in perceptual atypicalities in AS has increased, reflected by recent reviews (Simmons et al., 2009; Berhmann et al., 2006; Dakin and Frith, 2006; Marco et al., 2011) and theoretical articles (Pellicano and Burr, 2012; Markram and Markram, 2010; Van de Cruys et al., 2014; Mottron et al., 2014). Clinically, greater importance has been recently placed on the presence of non-social, visually-related diagnostic criteria of AS in the DSM 5; i.e., hyper-or hyporeactivity to sensory input, or unusual interests in sensory aspects of the environment, such as intense preoccupation to light or spinning objects (American Psychiatric Association, 2013). "
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    ABSTRACT: Background: Most investigations of visuo-perceptual abilities in the Autism Spectrum (AS) are level-specific, using tasks that selectively solicit either lower- (i.e., spatial frequency sensitivity), mid- (i.e., pattern discrimination) or higher-level processes (i.e., face identification) along the visual hierarchy. Less is known about how alterations at one level of processing (i.e., low-level) interact with that of another (i.e., mid-level). The aim of this study was to assess whether manipulating the physical properties (luminance vs. texture) of local contour elements of a mid-level, visual pattern interferes with the discrimination of that pattern in a differential manner for individuals with AS. Methods: Twenty-nine AS individuals and thirty control participants (range 14-27 years) were asked to discriminate between perfect circles and Radial Frequency Patterns (RFP) of two, three, five, and 10 radial frequencies (RF), or deformations along the pattern's contour. When RFP have few deformations (< five RF), a global, pattern analysis is needed for shape discrimination. Conversely, when RFP contain many deformations (≥ 10 RF), discrimination is dependent on the analysis of local deformations along the RFP contour. The effect of manipulating RF on RFP discrimination was assessed for RFP whose local contour elements were defined by either luminance or texture information, the latter previously found less efficiently processed in AS individuals. Results: Two separate mixed factorial ANOVAs [2 (Group) x 4 (RF)] were conducted on mean deformation thresholds for luminance- and texture-defined conditions. A significant Group x RF interaction was found for the luminance-defined condition where thresholds were higher in the AS group for the two and three RF conditions; no between-group differences were found for the five and 10 RF conditions. A significant main effect of group was identified for the texture-defined condition, where mean thresholds were higher for the AS group across all RF conditions assessed (two, three, five and 10); a Group x RF interaction effect was not found. Performance for each RFP condition was not affected across group by either chronological age or intelligence, as measured by either Weschler scales or Raven Progressive Matrices. Conclusions: The ability of AS individuals to discriminate a circular pattern is differentially affected by the availability (number of deformations along the RFP contour) and type (luminance versus texture) of local, low-level elements defining its contour. Performance is unaffected in AS when RFP discrimination is dependent on the analysis of local deformations of luminance-defined contour elements, but decreased across all RF conditions when local contour elements are texture-defined. These results suggest that efficient pattern perception in AS is functionally related to the efficacy with which its local elements are processed, indicative of an early origin for altered mid-level, pattern perception in AS.
    Neuropsychologia 09/2015; 77. DOI:10.1016/j.neuropsychologia.2015.09.022 · 3.30 Impact Factor
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