Visual working memory and sensory processing in autistic children.

While atypical sensory processing is one of the more ubiquitous symptoms in autism spectrum disorder, the exact nature of these sensory issues remains unclear, with different studies showing either enhanced or deficient sensory processing. Using a well-established continuous cued-recall task that assesses visual working memory, the current study provides novel evidence reconciling these apparently discrepant findings. Autistic children exhibited perceptual advantages in both likelihood of recall and recall precision relative to their typically-developed peers. When autistic children did make errors, however, they showed a higher probability of erroneously binding a given colour with the incorrect spatial location. These data align with neural-architecture models for feature binding in visual working memory, suggesting that atypical population-level neural noise in the report dimension (colour) and cue dimension (spatial location) may drive both the increase in probability of recall and precision of colour recall as well as the increase in proportion of binding errors when making an error, respectively. These changes are likely to impact core symptomatology associated with autism, as perceptual binding and working memory play significant roles in higher-order tasks, such as communication.

A pupillometry study of multisensory social and linguistic processing in autism and typical development.

Autism spectrum disorder is a neurodevelopmental disorder that is characterized by impairments in social communication, restricted interests, and repetitive behaviors. Many studies have demonstrated atypical responses to audiovisual sensory inputs, particularly those containing sociolinguistic information. It is currently unclear whether these atypical responses are due to the linguistic nature of the inputs or the social aspect itself. Further, it is unclear how atypical sensory responses to sociocommunicative stimuli intersect with autism symptomatology. The current study addressed these outstanding questions by using pupillometry in mental age-matched children with and without autism (N = 71) to examine physiological responses to dynamic, audiovisual stimuli including social, sociolinguistic, socioemotional, and nonsocial stimuli, as well as to temporally manipulated stimuli. Data revealed group differences in pupillary responses with social stimuli but not nonsocial stimuli and, importantly, showed no variation through the inclusion of linguistic or emotional information. This suggests that atypical sensory responses are driven primarily by the inclusion of social information broadly. Further, individual responses to social stimuli were significantly correlated with a wide range of autism spectrum disorder symptomatology, including social communication, restricted interests and repetitive behaviors, and sensory processing issues. Pupillary responses to social but not nonsocial presentation were also capable of predicting diagnosis with a high level of selectivity, but only with marginal sensitivity. Finally, responses to the temporal manipulation did not yield any group differences, suggesting that while atypical multisensory temporal processing has been well documented in autism at the level of behavior and perception, these issues may be intact at the physiological level. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Vocal characteristics of 5-year-old children: proposed normative values based on a French-speaking population†.

Purpose: Previous research proposed normative data on gender- and age-specific voice acoustics for adults. Such reference values are lacking for children, particularly under the age of 6. This study was intended (1) to collect reliable normative data for the acoustic parameters of 5-year-old children's voices, and (2) to investigate potential gender-specific differences.Study: Prospective and cross-sectional.Methods: Acoustic analyses were done on the voices of 53 normophonic children (26 girls; 27 boys) aged 5;0-5;11 years, using Praat software. The fundamental frequency, local jitter, local shimmer, and noise-to-harmonics ratio (NHR) were measured on the sustained vowels [a], [i], and [u]. The highest frequency, lowest frequency, and frequency range were measured using ascending and descending glissandi on the vowel [a].Results: For the three sustained vowels, the mean fundamental frequency ranged from 255 Hz to 277 Hz, mean jitter ranged from 0.394% to 0.591%, mean shimmer ranged from 2.571% to 5.824%, and mean NHR ranged from 0.009 to 0.034. The frequency range was from 190 Hz to 750 Hz, which corresponds to 23.7 semitones. No gender difference was found, except for NHR on the vowel [a].Conclusions: The lack of gender differences - other than for NHR on the vowel [a] - led us to propose mixed norms for 5-year-old boys and girls combined.Implications: These normative data will allow clinicians to compare children's voice assessments to specific references in order to enhance diagnostic accuracy and measure therapy outcomes.

The cascading influence of multisensory processing on speech perception in autism.

It has been recently theorized that atypical sensory processing in autism relates to difficulties in social communication. Through a series of tasks concurrently assessing multisensory temporal processes, multisensory integration and speech perception in 76 children with and without autism, we provide the first behavioral evidence of such a link. Temporal processing abilities in children with autism contributed to impairments in speech perception. This relationship was significantly mediated by their abilities to integrate social information across auditory and visual modalities. These data describe the cascading impact of sensory abilities in autism, whereby temporal processing impacts multisensory information of social information, which, in turn, contributes to deficits in speech perception. These relationships were found to be specific to autism, specific to multisensory but not unisensory integration, and specific to the processing of social information.

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.

Linking Anxiety and Insistence on Sameness in Autistic Children: The Role of Sensory Hypersensitivity.

Sensory hypersensitivity and insistence on sameness (I/S) are common, co-occurring features of autism, yet the relationship between them is poorly understood. This study assessed the impact of sensory hypersensitivity on the clinical symptoms of specific phobia, separation anxiety, social anxiety and I/S for autistic and typically developing (TD) children. Parents of 79 children completed questionnaires on their child's difficulties related to sensory processing, I/S, and anxiety. Results demonstrated that sensory hypersensitivity mediated 67% of the relationship between symptoms of specific phobia and I/S and 57% of the relationship between separation anxiety and I/S. No relationship was observed between sensory hypersensitivity and social anxiety. These mediation effects of sensory hypersensitivity were found only in autistic children, not in TD children.

Multisensory speech perception in autism spectrum disorder: From phoneme to whole-word perception.

Speech perception in noisy environments is boosted when a listener can see the speaker's mouth and integrate the auditory and visual speech information. Autistic children have a diminished capacity to integrate sensory information across modalities, which contributes to core symptoms of autism, such as impairments in social communication. We investigated the abilities of autistic and typically-developing (TD) children to integrate auditory and visual speech stimuli in various signal-to-noise ratios (SNR). Measurements of both whole-word and phoneme recognition were recorded. At the level of whole-word recognition, autistic children exhibited reduced performance in both the auditory and audiovisual modalities. Importantly, autistic children showed reduced behavioral benefit from multisensory integration with whole-word recognition, specifically at low SNRs. At the level of phoneme recognition, autistic children exhibited reduced performance relative to their TD peers in auditory, visual, and audiovisual modalities. However, and in contrast to their performance at the level of whole-word recognition, both autistic and TD children showed benefits from multisensory integration for phoneme recognition. In accordance with the principle of inverse effectiveness, both groups exhibited greater benefit at low SNRs relative to high SNRs. Thus, while autistic children showed typical multisensory benefits during phoneme recognition, these benefits did not translate to typical multisensory benefit of whole-word recognition in noisy environments. We hypothesize that sensory impairments in autistic children raise the SNR threshold needed to extract meaningful information from a given sensory input, resulting in subsequent failure to exhibit behavioral benefits from additional sensory information at the level of whole-word recognition. Autism Res 2017. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. Autism Res 2017, 10: 1280-1290. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

Keeping time in the brain: Autism spectrum disorder and audiovisual temporal processing.

A growing area of interest and relevance in the study of autism spectrum disorder (ASD) focuses on the relationship between multisensory temporal function and the behavioral, perceptual, and cognitive impairments observed in ASD. Atypical sensory processing is becoming increasingly recognized as a core component of autism, with evidence of atypical processing across a number of sensory modalities. These deviations from typical processing underscore the value of interpreting ASD within a multisensory framework. Furthermore, converging evidence illustrates that these differences in audiovisual processing may be specifically related to temporal processing. This review seeks to bridge the connection between temporal processing and audiovisual perception, and to elaborate on emerging data showing differences in audiovisual temporal function in autism. We also discuss the consequence of such changes, the specific impact on the processing of different classes of audiovisual stimuli (e.g. speech vs. nonspeech, etc.), and the presumptive brain processes and networks underlying audiovisual temporal integration. Finally, possible downstream behavioral implications, and possible remediation strategies are outlined. Autism Res 2016, 9: 720-738. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

What do we know about suicidality in autism spectrum disorders? A systematic review.

Suicidality is a common and concerning issue across development, and there is a plethora of research on this topic among typically developing children and youth. Very little is known, however, about the nature of suicidality among individuals with autism spectrum disorders (ASDs). The purpose of the current study was to undertake a systematic literature review to assess the current state of the research literature to examine the prevalence of suicidality among individuals with ASD, related demographic and clinical profiles, and associated risk and protective factors. A literature search using key terms related to suicidality and ASD yielded 10 topical studies that were evaluated for the study objectives. Suicidality was present in 10.9-50% of the ASD samples identified in the systematic review. Further, several large-scale studies found that individuals with ASD comprised 7.3-15% of suicidal populations, a substantial subgroup. Risk factors were identified and included peer victimization, behavioral problems, being Black or Hispanic, being male, lower socioeconomic status, and lower level of education. Only one study reported on protective factors, and this is identified as a significant gap in the literature. Several methodological weaknesses were present in the current literature, such as lack of appropriate comparison groups and little to no use of empirically validated measures for ASD diagnosis and suicide assessment. Additional research is necessary to understand better how this unique population experiences and expresses suicidal tendencies. Recommendations for future research are discussed.