Variable sensory perception in autism

Abstract

Autism is associated with sensory and cognitive abnormalities. Individuals with autism generally show normal or superior early sensory processing abilities compared to healthy controls, but deficits in complex sensory processing. In the current opinion paper, it will be argued that sensory abnormalities impact cognition by limiting the amount of signal that can be used to interpret and interact with environment. There is a growing body of literature showing that individuals with autism exhibit greater trial-to-trial variability in behavioural and cortical sensory responses. If multiple sensory signals that are highly variable are added together to process more complex sensory stimuli, then this might destabilise later perception and impair cognition. Methods to improve sensory processing have shown improvements in more general cognition. Studies that specifically investigate differences in sensory trial-to-trial variability in autism, and the potential changes in variability before and after treatment, could ascertain if trial-to-trial variability is a good mechanism to target for treatment in autism.

Thermal Perceptual Thresholds are typical in Autism Spectrum Disorder but Strongly Related to Intra-individual Response Variability

“…Although we have described a robust relationship between variability and detection threshold in this paradigm, it is beyond the scope of this study to determine the underlying cause of this effect. These data, alongside the significant group differences in GMD , seem to support the hypothesis that sensory features of ASD are the result of more unreliable perception, as reflected in increased trial-to-trial variability 41–44 . Noisier perceptions in ASD could theoretically delay perceptual decision-making and increase detection thresholds to a small degree 61 .…”

“…We also extended the work of prior authors by examining the degree to which psychophysical thresholds are associated with individual differences in age, sex, IQ, and common measures of autism symptomatology (ADOS-2 Calibrated Severity Score [CSS] 34–36 , Social Responsiveness Scale – Second Edition [SRS-2] 37 ), including sensory features (Adolescent/Adult Sensory Profile [AASP] 38,39 and Sensory Profile [SP] 40 quadrant scores, as well as a one-item measure of sensory hyperresponsivity derived from the SRS-2). Lastly, as some studies have linked ASD to increasingly noisy and variable perceptions 41–44 , we investigated diagnostic group differences in intra-individual variability in warm and cool threshold temperatures across individual trials of our experimental task (as measured by Gini’s Mean Difference [ GMD ] 45–47 ), as well as the relationships between GMD values and detection thresholds derived from those same trials.…”

The Potential of Trial-by-Trial Variabilities of Ongoing-EEG, Evoked Potentials, Event Related Potentials and fMRI as Diagnostic Markers for Neuropsychiatric Disorders

“…The theme of “neuronal variability” is of great importance in the characterization of the “inter and intra-subject variability,” a concept that is becoming crucial to understand neuronal adaptation and plasticity in aging, and many pathological conditions of the brain. There are many comprehensive reviews about the “inter and intra-subject variability” of many behavioral and brain signals, in patients with neurological disorders and healthy controls (MacDonald et al, 2006, 2009; Faisal et al, 2008; Fontanini and Katz, 2008; Geurts et al, 2008; Vanrullen et al, 2011; Dykiert et al, 2012; Tamm et al, 2012; Garrett et al, 2013; Kofler et al, 2013; Dinstein et al, 2015; Dhawale et al, 2017; Ouyang et al, 2017; Tian et al, 2017; Haigh, 2018). However, there are no reviews focused on the “inter and intra-subject variability” for evoked potentials (EP) or event related potentials (ERP).…”

Explorations and perspectives on the neurobiological bases of autism spectrum disorder

“…This is a readily testable hypothesis, as the prediction is that there will be higher trial‐to‐trial variance in the sensory‐perceptual responses of individuals with an ASD, which can be measured with high fidelity using modern neurophysiological techniques such as functional imaging and event‐related potentials (ERPs). However, as reviewed by Haigh, the literature is inconclusive when it comes to the so‐called neural unreliability thesis (Haigh, ). Haigh suggests that increased variance in the neural response in ASD may be more apparent for complex vs. simple stimuli and may also be more apparent under conditions that are more demanding.…”

“…Basic sensory‐perceptual anomalies are a recurrent theme in ASD and lend themselves very well to investigation with current neurophysiological and neuroimaging techniques. Here, a set of studies report on such diverse processes as auditory spatial processing, pain anticipation, and error registration (Gu et al ., ; Kim et al ., ; Lodhia et al ., ), and an opinion piece by Sarah Haigh of the University of Pittsburgh presents evidence both for and against what we call the ‘neural unreliability’ hypothesis, the notion that initial cortical sensory responses to repeated events are more variable across trials in ASD (Dinstein et al ., ; Haigh et al ., , ; Butler et al ., ; Haigh, ).…”