Auditory and Visual Statistical Learning Are Not Related to ADHD Symptomatology: Evidence From a Research Domain Criteria (RDoC) Approach

Statistical learning is an implicit process that allows individuals to track and predict incoming events from their environment. Given that information is highly structured over time, events become predictable, allowing these individuals to make better sense of their environment. Among the studies that have examined statistical learning in attention deficit/hyperactivity disorder (ADHD), findings have been mixed. Our goal was to examine whether increased ADHD symptomatology related to decreased auditory and visual statistical learning abilities. To investigate this, we examined the entire range of ADHD symptomatology using a Research Domain Criteria approach with a clinically reliable questionnaire in addition to well-established auditory and visual statistical learning paradigms. Total ADHD symptomatology was not related to auditory and visual statistical learning. An identical pattern emerged when inattention and hyperactivity components were separated, indicating that neither of these distinct behavioral symptoms of ADHD are related to statistical learning abilities. Findings from the current study converge with other studies but go beyond finding a lack of a significant relationship – through Bayesian analyses, these data provide novel evidence directly supporting the hypothesis that ADHD symptomatology and statistical learning are decoupled. This finding held for overall levels of ADHD symptomatology as well as the subdomains of inattention and hyperactivity, suggesting that the ability to pick up on patterns in both auditory and visual domains is intact in ADHD. Future work should consider investigating statistical learning in ADHD across ages and beyond auditory and visual domains

Auditory Sensory Filtering and Development in Children with Autism Spectrum Disorder

Sensory filtering is the process of separating and distilling relevant sensory information from irrelevant, which in turn greatly reduces the quantity of sensory information that is fully processed and leads to significant increases in efficiency. Atypical sensory filtering can result in sensory hypo- or hypersensitivity — atypical sensory filtering and hypo/hypersensitivity have been observed in people with autism. Atypical sensory filtering contributes to canonical symptoms in Autism. Sensory filtering can be measured in a few different ways, one of which is the Acoustic Startle Response (ASR). ASR is a reflexively produced muscular reaction to sudden auditory stimuli. Our study aims to manipulate characteristics of auditory stimuli (acoustic reactivity, PPI, and habituation) and observe their subsequent effects on the startle response. Furthermore, observe potential differences in the startle response after these manipulations between ASD and neurotypical children. Differences between these two groups has been observed in prior literature, such as Takahashi et al.\u27s papers in 2014 and 2016, but results have been mixed. Our study hopes to provide more clarity to these mixed findings, through hypothesising that autistic participants will display increased startle compared to neurotypical children under various manipulation\u27s. This research may provide further evidence of sensory filtering differences in ASD, alongside gaining a greater understanding of the underpinnings of symptomology

Behavioral, perceptual, and neural alterations in sensory and multisensory function in autism spectrum disorder.

Although sensory processing challenges have been noted since the first clinical descriptions of autism, it has taken until the release of the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) in 2013 for sensory problems to be included as part of the core symptoms of autism spectrum disorder (ASD) in the diagnostic profile. Because sensory information forms the building blocks for higher-order social and cognitive functions, we argue that sensory processing is not only an additional piece of the puzzle, but rather a critical cornerstone for characterizing and understanding ASD. In this review we discuss what is currently known about sensory processing in ASD, how sensory function fits within contemporary models of ASD, and what is understood about the differences in the underlying neural processing of sensory and social communication observed between individuals with and without ASD. In addition to highlighting the sensory features associated with ASD, we also emphasize the importance of multisensory processing in building perceptual and cognitive representations, and how deficits in multisensory integration may also be a core characteristic of ASD

A Systematic Review of Brainstem Contributions to Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a neurodevelopmental disorder that affects one in 66 children in Canada. The contributions of changes in the cortex and cerebellum to autism have been studied for decades. However, our understanding of brainstem contributions has only started to emerge more recently. Disruptions of sensory processing, startle response, sensory filtering, sensorimotor gating, multisensory integration and sleep are all features of ASD and are processes in which the brainstem is involved. In addition, preliminary research into brainstem contribution emphasizes the importance of the developmental timeline rather than just the mature brainstem. Therefore, the purpose of this systematic review is to compile histological, behavioral, neuroimaging, and electrophysiological evidence from human and animal studies about brainstem contributions and their functional implications in autism. Moreover, due to the developmental nature of autism, the review pays attention to the atypical brainstem development and compares findings based on age. Overall, there is evidence of an important role of brainstem disruptions in ASD, but there is still the need to examine the brainstem across the life span, from infancy to adulthood which could lead the way for early diagnosis and possibly treatment of ASD

Multisensory Integration and Autistic Traits Using Non-Sociolinguistic Information

Background: Sensory processing issues are one of the most common complaints in autism spectrum disorder (ASD). One area of sensory difficulties in ASD that has been the focus of intense research in recent years is multisensory integration (MSI), or the ability to bind auditory and visual information into a single, unified percept. While integration of social or linguistic information is consistently shown to be an area of difficulty in ASD, results are less clear with simple, non-sociolinguistic stimuli. This study aims to address this ambiguity by determining whether MSI of non-sociolinguistic sensory information is related to traits and symptomatology commonly associated with ASD. Methods: Sixty-five undergraduate students completed a behavioural audiovisual detection task and a battery of questionnaires assessing ASD-related traits and symptomatology. Multisensory enhancement (ME) was measured by comparing accuracy rates during audiovisual trials to the accuracy rate predicted by the unisensory conditions assuming independent processing: (AVacc-[Aacc+Vacc-(Aacc*Vacc)]). Results: Results revealed no relationship between ME of simple, non-sociolinguistic sensory information and autistic traits and symptomatology, with R-squared values ranging between 0.001-0.03. Discussion & Conclusion: While MSI issues are well established with sociolinguistic stimuli, these data suggest that these issues may be restricted to social or linguistic information. The lack of any relationship between ME and ASD traits spanned a range of symptoms, including repetitive behaviours, social communication, and sensory issues, suggesting MSI may be associated with autism symptomatology only when sociolinguistic information is present. Interdisciplinary Reflection: This research combines behavioural measures of sensory perception and diagnostic criteria used in clinical settings to assess ASD traits

Conjunctive Visual Processing Appears Abnormal in Autism

Face processing in autism spectrum disorder (ASD) is thought to be atypical, but it is unclear whether differences in visual conjunctive processing are specific to faces. To address this, we adapted a previously established eye-tracking paradigm which modulates the need for conjunctive processing by varying the degree of feature ambiguity in faces and objects. Typically-developed (TD) participants showed a canonical pattern of conjunctive processing: High-ambiguity objects were processed more conjunctively than low-ambiguity objects, and faces were processed in an equally conjunctive manner regardless of ambiguity level. In contrast, autistic individuals did not show differences in conjunctive processing based on stimulus category, providing evidence that atypical visual conjunctive processing in ASD is the result of a domain general lack of perceptual specialization

The relationship between multisensory associative learning and multisensory integration

Integrating sensory information from multiple modalities leads to more precise and efficient perception and behaviour. The process of determining which sensory information should be perceptually bound is reliant on both low-level stimulus features, as well as multisensory associations learned throughout development based on the statistics of our environment. Here, we explored the relationship between multisensory associative learning and multisensory integration using encephalography (EEG) and behavioural measures. Sixty-one participants completed a three-phase study. First, participants were exposed to novel audiovisual shape-tone pairings with frequent and infrequent stimulus pairings and completed a target detection task. EEG recordings of the mismatch negativity (MMN) and P3 were calculated as neural indices of multisensory associative learning. Next, the same learned stimulus pairs were presented in audiovisual as well as unisensory auditory and visual modalities while both early (\u3c100 ms) and late neural indices of multisensory integration were recorded. Finally, participants completed an analogous behavioural speeded-response task, with behavioural indices of multisensory gain calculated using the Race Model. Significant relationships were found in fronto-central and occipital areas between neural measures of associative learning and both early and late indices of multisensory integration in frontal and centro-parietal areas, respectively. Participants who showed stronger indices of associative learning also exhibited stronger indices of multisensory integration of the stimuli they learned to associate. Furthermore, a significant relationship was found between neural index of early multisensory integration and behavioural indices of multisensory gain. These results provide insight into the neural underpinnings of how higher-order processes such as associative learning guide multisensory integration

The impact of multisensory integration deficits on speech perception in children with autism spectrum disorders.

Speech perception is an inherently multisensory process. When having a face-to-face conversation, a listener not only hears what a speaker is saying, but also sees the articulatory gestures that accompany those sounds. Speech signals in visual and auditory modalities provide complementary information to the listener (Kavanagh and Mattingly, 1974), and when both are perceived in unison, behavioral gains in in speech perception are observed (Sumby and Pollack, 1954). Notably, this benefit is accentuated when speech is perceived in a noisy environment (Sumby and Pollack, 1954). To achieve a behavioral gain from multisensory processing of speech, however, the auditory and visual signals must be perceptually bound into a single, unified percept. The most commonly cited effect that demonstrates perceptual binding in audiovisual speech perception is the McGurk effect (McGurk and MacDonald, 1976), where a listener hears a speaker utter the syllable “ba,” and sees the speaker utter the syllable “ga.” When these two speech signals are perceptually bound, the listener perceives the speaker as having said “da” or “tha,” syllables that are not contained in either of the unisensory signals, resulting in a perceptual binding, or integration, of the speech signals (Calvert and Thesen, 2004)

Investigating the Role of Inattention and/or Hyperactivity/impulsivity in Language and Social Functioning Using a Dimensional Approach

© 2020 Elsevier Inc. The current study parsed out the distinct components of attention-deficit/hyperactivity disorder (ADHD) symptomatology to examine differential relations with language and social ability. Using a research domain criteria (RDoC) framework, we administered standardized tests and previously developed and validated questionnaires to assess levels of inattention and/or hyperactivity/impulsivity symptomatology, language, social responsivity and social competency in 98 young adults. Those with higher inattention and/or hyperactivity/impulsivity symptomatology had reduced language comprehension, social responsivity, and social competency. Inattention and hyperactivity/impulsivity both predicted language comprehension, but not language production. Interestingly, inattention uniquely contributed to social responsiveness and social competency, but hyperactivity/impulsivity did not. Findings suggest that inattention and/or hyperactivity/impulsivity symptoms, inattention in particular, may be especially important for social skills programs geared towards individuals with attention limitations

Seeing the Forest and the Trees: Default Local Processing in Individuals with High Autistic Traits Does Not Come at the Expense of Global Attention.

Atypical sensory perception is one of the most ubiquitous symptoms of autism, including a tendency towards a local-processing bias. We investigated whether local-processing biases were associated with global-processing impairments on a global/local attentional-scope paradigm in conjunction with a composite-face task. Behavioural results were related to individuals\u27 levels of autistic traits, specifically the Attention to Detail subscale of the Autism Quotient, and the Sensory Profile Questionnaire. Individuals showing high rates of Attention to Detail were more susceptible to global attentional-scope manipulations, suggesting that local-processing biases associated with Attention to Detail do not come at the cost of a global-processing deficit, but reflect a difference in default global versus local bias. This relationship operated at the attentional/perceptual level, but not response criterion