Heterogeneity of sensory features in autism spectrum disorder: Challenges and perspectives for future research

Global Sensory Features are Linked to Executive and Attentional Impairments in Autism Spectrum Disorders

Sensory features, executive and attentional impairments are frequently reported in individuals with autism spectrum disorders (ASD). However, little is known about their complex relationships. In this study, we aim to examine the executive and attentional difficulties related to distinct sensory profiles. We identified sensory profiles with a Latent Profile Analysis (LPA) based on scores on the Short Sensory Profile (SSP) questionnaire in 95 children with ASD aged 6 to 17 years. Executive and attention functions were assessed using the Behavior Rating Inventory of Executive Functions (BRIEF) questionnaire and Attention-Deficit Hyperactivity Disorder Rating Scale (ADHD-RS). A three-cluster solution based on raw SSP scores identified a "high'', a "medium" and a "low'' SSP profile. We found a significant relationship between executive functions, attentional skills and the global severity of sensory features, reinforcing findings of previous studies in the literature. A two-cluster solution based on normalized SSP (i.e. equalized for the global severity) identified distinct sensory profiles, mainly discriminated by the score of underresponsive/seeks sensation. We found no significant difference between these two clusters for the BRIEF and ADHD-RS related scores. Our study suggests that the heterogeneity of sensory features in ASD may not be explained by differences in executive and attention functions. Future studies are needed to refine the link between sensory features and executive functions in autism.

Approaches to improving mental health care for autistic children and young people: a systematic review and meta-analysis

Autistic children and young people (CYP) experience mental health difficulties but face many barriers to accessing and benefiting from mental health care. There is a need to explore strategies in mental health care for autistic CYP to guide clinical practice and future research and support their mental health needs. Our aim was to identify strategies used to improve mental health care for autistic CYP and examine evidence on their acceptability, feasibility, and effectiveness. A systematic review and meta-analysis were carried out. All study designs reporting acceptability/feasibility outcomes and empirical quantitative studies reporting effectiveness outcomes for strategies tested within mental health care were eligible. We conducted a narrative synthesis and separate meta-analyses by informant (self, parent, and clinician). Fifty-seven papers were included, with most investigating cognitive behavioral therapy (CBT)-based interventions for anxiety and several exploring service-level strategies, such as autism screening tools, clinician training, and adaptations regarding organization of services. Most papers described caregiver involvement in therapy and reported adaptations to communication and intervention content; a few reported environmental adjustments. In the meta-analyses, parent- and clinician-reported outcomes, but not self-reported outcomes, showed with moderate certainty that CBT for anxiety was an effective treatment compared to any comparison condition in reducing anxiety symptoms in autistic individuals. The certainty of evidence for effectiveness, synthesized narratively, ranged from low to moderate. Evidence for feasibility and acceptability tended to be positive. Many identified strategies are simple, reasonable adjustments that can be implemented in services to enhance mental health care for autistic individuals. Notable research gaps persist, however.

The effects of service dogs for children with autism spectrum disorder and their caregivers: a cross-sectional study

Introduction

Service dogs are an increasingly popular complementary intervention for children with autism spectrum disorder. However, despite increasing demand, there remains a lack of empirical research on their potential benefits. The purpose of this study was to evaluate the effects of service dogs on children with autism and their caregivers.

Methods

A total of N = 75 families of children with autism were recruited from a non-profit service dog provider in the US, including n = 39 families previously placed with a service dog and n = 36 families engaging in usual care while on the waitlist. Caregivers completed an online survey containing both self- and proxy-report standardized measures of child, caregiver, and family functioning. Linear regressions modeled the relationship between service dog presence and survey outcomes, controlling for relevant child and caregiver covariates.

Results

Results indicated that having a service dog was associated with significantly better child sleep behaviors, including better sleep initiation and duration and less sleep anxiety/co-sleeping with medium effect sizes. However, service dog presence was not significantly related to child withdrawal, negative emotionality, emotional self-control, hyperactivity, irritability, and lethargy with small effect sizes. For caregivers, having a service dog was not significantly related to standardized measures of caregiver strain, sleep disturbance, depression, or the impact of the child's condition on family functioning with small effect sizes. Supplemental matched case-control analyses confirmed these findings.

Discussion

In conclusion, service dogs were found to positively impact sleep behaviors among children with autism, but may not uniformly relate to other areas of child and caregiver wellbeing. Prospective longitudinal designs, larger sample sizes able to detect small effects, and studies that measure sleep using objective methods are needed to build on these findings.

Atypical Impact of Action Effect Delay on Motor Performance in Autism

Atypical sensory perception and motor impairments are primary features of autism spectrum disorder (ASD) that indicate atypical development and predict social and non-social challenges. However, their link is poorly understood. Sensory perception is often integrated with motor processes when a sensory effect is temporally contiguous with the motor response. Such sensory-motor coupling further improves motor behavior. Previous studies indicate alterations in sensory perception of action-effect temporal contiguity in ASD, which bares the question of how it may impact motor performance. People diagnosed with ASD and typically developed (TD) participants performed a speeded reaction-time task previously established to capture the facilitating impact of action's perceptual effect on motor response selection. The sensitivity of this mechanism to delays in the effect was measured, manipulating the action-effect temporal contiguity in a within-subject design. An immediate action effect (compared to a No-effect condition) facilitated response selection in the TD group. This facilitation effect was evident in the ASD group but did not show the typical sensitivity to the effect delay. While in the TD group, RT was shorter in the short (225ms) compared to the long (675ms) action effect delay condition, this distinguished pattern was absent in the ASD group. The findings provide supporting evidence that atypical motor performance in ASD results, at least in part, from an altered sensory perception of action effect temporal contiguity. We discuss the results in light of the reduced perceptual specialization account in ASD and its potential for undermining adaptive sensorimotor processes.

Early developmental profiles of sensory features and links to school-age adaptive and maladaptive outcomes: A birth cohort investigation

Sensory-based subtypes among autistic children have been well documented, but little is known about longitudinal sensory subtypes beyond autistic populations. This prospective study aimed to identify subtypes based on trajectories of parent-reported sensory features measured at 6-19 months, 3-4, and 6-7 years of age among a community-based birth cohort (N = 1,517), and to examine their associations with school-age clinical and adaptive/maladaptive outcomes on a subset sample (N = 389). Latent class growth analysis revealed five trajectory subtypes varying in intensity and change rates across three sensory domains. In contrast to an Adaptive-All Improving subtype (35%) with very low sensory features and overall better school-age outcomes, an Elevated-All Worsening subtype (3%), comprised of more boys and children of parents with less education, was associated with most elevated autistic traits and poorest adaptive/maladaptive outcomes. Three other subtypes (62% in total) were generally characterized by stable or improving patterns of sensory features at mild to moderate levels, and challenges in certain outcome domains. Our findings indicate that characterizing children based on early sensory trajectories may contribute to earlier detection of subgroups of children with sensory challenges who are more likely to experience developmental challenges by school age, followed by early targeted interventions for improved long-term outcomes.

Prolonged neural encoding of visual information in autism

Autism spectrum disorder (ASD) is associated with a hyper-focused visual attentional style, impacting higher-order social and affective domains. The understanding of such peculiarity can benefit from the use of multivariate pattern analysis (MVPA) of high-resolution electroencephalography (EEG) data, which has proved to be a powerful technique to investigate the hidden neural dynamics orchestrating sensory and cognitive processes. Here, we recorded EEG in typically developing (TD) children and in children with ASD during a visuo-spatial attentional task where attention was exogenously captured by a small (zoom-in) or large (zoom-out) cue in the visual field before the appearance of a target at different eccentricities. MVPA was performed both in the cue-locked period, to reveal potential differences in the modulation of the attentional focus, and in the target-locked period, to reveal potential cascade effects on stimulus processing. Cue-locked MVPA revealed that while in the TD group the pattern of neural activity contained information about the cue mainly before the target appearance, the ASD group showed a temporally sustained and topographically diffuse significant decoding of the cue neural response even after the target onset, suggesting a delayed extinction of cue-related neural activity. Crucially, this delayed extinction positively correlated with behavioral measures of attentional hyperfocusing. Results of target-locked MVPA were coherent with a hyper-focused attentional profile, highlighting an earlier and stronger decoding of target neural responses in small cue trials in the ASD group. The present findings document a spatially and temporally overrepresented encoding of visual information in ASD, which can constitute one of the main reasons behind their peculiar cognitive style.

Endogenous noise of neocortical neurons correlates with atypical sensory response variability in the Fmr1-/y mouse model of autism

Excessive neural variability of sensory responses is a hallmark of atypical sensory processing in autistic individuals with cascading effects on other core autism symptoms but unknown neurobiological substrate. Here, by recording neocortical single neuron activity in a well-established mouse model of Fragile X syndrome and autism, we characterized atypical sensory processing and probed the role of endogenous noise sources in exaggerated response variability in males. The analysis of sensory stimulus evoked activity and spontaneous dynamics, as well as neuronal features, reveals a complex cellular and network phenotype. Neocortical sensory information processing is more variable and temporally imprecise. Increased trial-by-trial and inter-neuronal response variability is strongly related to key endogenous noise features, and may give rise to behavioural sensory responsiveness variability in autism. We provide a novel preclinical framework for understanding the sources of endogenous noise and its contribution to core autism symptoms, and for testing the functional consequences for mechanism-based manipulation of noise.

Exploring the multidimensional nature of repetitive and restricted behaviors and interests (RRBI) in autism: neuroanatomical correlates and clinical implications

BACKGROUND

Repetitive and restricted behaviors and interests (RRBI) are core symptoms of autism with a complex entity and are commonly categorized into 'motor-driven' and 'cognitively driven'. RRBI symptomatology depends on the individual's clinical environment limiting the understanding of RRBI physiology, particularly their associated neuroanatomical structures. The complex RRBI heterogeneity needs to explore the whole RRBI spectrum by integrating the clinical context [autistic individuals, their relatives and typical developing (TD) individuals]. We hypothesized that different RRBI dimensions would emerge by exploring the whole spectrum of RRBI and that these dimensions are associated with neuroanatomical signatures-involving cortical and subcortical areas.

METHOD

A sample of 792 individuals composed of 267 autistic subjects, their 370 first-degree relatives and 155 TD individuals was enrolled in the study. We assessed the whole patterns of RRBI in each individual by using the Repetitive Behavior Scale-Revised and the Yale-Brown Obsessive Compulsive Scale. We estimated brain volumes using MRI scanner for a subsample of the subjects (n = 152, 42 ASD, 89 relatives and 13 TD). We first investigated the dimensionality of RRBI by performing a principal component analysis on all items of these scales and included all the sampling population. We then explored the relationship between RRBI-derived factors with brain volumes using linear regression models.

RESULTS

We identified 3 main factors (with 30.3% of the RRBI cumulative variance): Factor 1 (FA1, 12.7%) reflected mainly the 'motor-driven' RRBI symptoms; Factor 2 and 3 (respectively, 8.8% and 7.9%) gathered mainly Y-BOCS related items and represented the 'cognitively driven' RRBI symptoms. These three factors were significantly associated with the right/left putamen volumes but with opposite effects: FA1 was negatively associated with an increased volume of the right/left putamen conversely to FA2 and FA3 (all uncorrected p < 0.05). FA1 was negatively associated with the left amygdala (uncorrected p < 0.05), and FA2 was positively associated with the left parietal structure (uncorrected p = 0.001).

CONCLUSION

Our results suggested 3 coherent RRBI dimensions involving the putamen commonly and other structures according to the RRBI dimension. The exploration of the putamen's integrative role in RSBI needs to be strengthened in further studies.

Differentiating early sensory profiles in toddlers at elevated likelihood of autism and association with later clinical outcome and diagnosis

LAY ABSTRACT

Early sensory responsiveness may produce cascading effects on later development, but the relation between sensory profiles and autistic diagnosis remains unclear. In a longitudinal sample of toddlers at elevated likelihood for autism, we aimed to characterize sensory subgroups and their association with clinical outcomes later on. Three sensory subgroups were described and early sensory sensitivity plays a significant role in later development and diagnosis. This study supported the importance of examining different levels of sensory patterns to dissect the phenotypic heterogeneity in sensory processing. As sensory differences are associated with later developmental outcomes, these results may be critical when designing intervention needs and support for children at increased likelihood for neurodevelopmental disorders.

An Observed Assessment of Sensory Responsivity in Autism Spectrum Disorders: Associations with Diagnosis, Age, and Parent Report

Sensory features are common and impairing in autism spectrum disorder (ASD), but there are few observational sensory assessments that are valid across ages. We used the Sensory Processing 3-Dimensional (SP3-D) observed Assessment and parent-reported Inventory to examine sensory responsivity in 41 ASD and 33 typically-developing (TD) youth across 7-17 years. ASD youth had higher and more variable observed and reported sensory responsivity symptoms compared to TD, but the two measures were not correlated. Observed sensory over-responsivity (SOR) and sensory craving (SC) decreased with age in ASD, though SOR remained higher in ASD versus TD through adolescence. Results suggest that in ASD, the SP3-D Assessment can identify SOR through adolescence, and that there is value in integrating multiple sensory measures.

Examining the latent structure and correlates of sensory reactivity in autism: a multi-site integrative data analysis by the autism sensory research consortium

BACKGROUND

Differences in responding to sensory stimuli, including sensory hyperreactivity (HYPER), hyporeactivity (HYPO), and sensory seeking (SEEK) have been observed in autistic individuals across sensory modalities, but few studies have examined the structure of these "supra-modal" traits in the autistic population.

METHODS

Leveraging a combined sample of 3868 autistic youth drawn from 12 distinct data sources (ages 3-18 years and representing the full range of cognitive ability), the current study used modern psychometric and meta-analytic techniques to interrogate the latent structure and correlates of caregiver-reported HYPER, HYPO, and SEEK within and across sensory modalities. Bifactor statistical indices were used to both evaluate the strength of a "general response pattern" factor for each supra-modal construct and determine the added value of "modality-specific response pattern" scores (e.g., Visual HYPER). Bayesian random-effects integrative data analysis models were used to examine the clinical and demographic correlates of all interpretable HYPER, HYPO, and SEEK (sub)constructs.

RESULTS

All modality-specific HYPER subconstructs could be reliably and validly measured, whereas certain modality-specific HYPO and SEEK subconstructs were psychometrically inadequate when measured using existing items. Bifactor analyses supported the validity of a supra-modal HYPER construct (ωH = .800) but not a supra-modal HYPO construct (ωH = .653), and supra-modal SEEK models suggested a more limited version of the construct that excluded some sensory modalities (ωH = .800; 4/7 modalities). Modality-specific subscales demonstrated significant added value for all response patterns. Meta-analytic correlations varied by construct, although sensory features tended to correlate most with other domains of core autism features and co-occurring psychiatric symptoms (with general HYPER and speech HYPO demonstrating the largest numbers of practically significant correlations).

LIMITATIONS

Conclusions may not be generalizable beyond the specific pool of items used in the current study, which was limited to caregiver report of observable behaviors and excluded multisensory items that reflect many "real-world" sensory experiences.

CONCLUSION

Of the three sensory response patterns, only HYPER demonstrated sufficient evidence for valid interpretation at the supra-modal level, whereas supra-modal HYPO/SEEK constructs demonstrated substantial psychometric limitations. For clinicians and researchers seeking to characterize sensory reactivity in autism, modality-specific response pattern scores may represent viable alternatives that overcome many of these limitations.

Forwarding the Science of Sensory Features in Autism and Related Conditions

This editorial accompanies the JADD Special Issue on Sensory Features in Autism and Related Conditions: Developmental Approaches, Mechanisms and Targeted Interventions. The editorial is a commentary on the state of the science in sensory features in autism and related conditions and provides a synopsis of the information contained in the special issue including provocative thoughts about moving the field forward in this area.

Characterizing Sensory Phenotypes of Subgroups with a Known Genetic Etiology Pertaining to Diagnoses of Autism Spectrum Disorder and Intellectual Disability

We aimed to identify unique constellations of sensory phenotypes for genetic etiologies associated with diagnoses of autism spectrum disorder (ASD) and intellectual disability (ID). Caregivers reported on sensory behaviors via the Sensory Profile for 290 participants (younger than 25 years of age) with ASD and/or ID diagnoses, of which ~ 70% have a known pathogenic genetic etiology. Caregivers endorsed poor registration (i.e., high sensory threshold, passive behaviors) for all genetic subgroups relative to an "idiopathic" comparison group with an ASD diagnosis and without a known genetic etiology. Genetic profiles indicated prominent sensory seeking in ADNP, CHD8, and DYRK1A, prominent sensory sensitivities in SCN2A, and fewer sensation avoidance behaviors in GRIN2B (relative to the idiopathic ASD comparison group).

The Sensory Observation Autism Rating Scale (SOAR): Developed using the PROMIS® framework

Autistic people experience the sensory world differently, impacting behavior. First-hand accounts and group-based research have found that sensory differences impact a range of things including family life, anxiety, participation, and daily living. Early sensory differences are widely reported to be associated with a cascade of developmental difference, suggesting that early autism diagnosis and sensory mapping could enable the provision of supports to facilitate flourishing. However, appropriate measurement tools are not available as all rely on proxy report or are observation measures which include limited modalities or domains and require the administration of stimuli. Therefore, following the gold-standard recommendations for measurement development outlined by the PROMIS® framework, we created the Sensory Observation Autism Rating scale (SOAR). We identified sensory behaviors across all primary domains and modalities through an extensive autism-sensory literature review and from focus groups with autism stakeholders. The initial item bank was then refined by an expert panel and through video coding five-minutes of free play from Autism Diagnostic Observation Schedule assessments of 105 age- and gender-matched autistic and developmentally delayed children (aged 13-36 months; 38 female). An additional 25% of the sample were double coded to investigate interrater reliability. Observational data and expert review supported the reduction of the item bank to 37 items. We propose that the refined SOAR has excellent face and ecological validity, along with interrater reliability (Intraclass correlation = 0.87-0.99). Following further data collection and refinement, SOAR has promise to fully characterize sensory behaviors in autistic children and indicate useful supports.

Tackling hypo and hyper sensory processing heterogeneity in autism: From clinical stratification to genetic pathways

As an integral part of autism spectrum symptoms, sensory processing issues including both hypo and hyper sensory sensitivities. These sensory specificities may result from an excitation/inhibition imbalance with a poorly understood of their level of convergence with genetic alterations in GABA-ergic and glutamatergic pathways. In our study, we aimed to characterize the hypo/hyper-sensory profile among autistic individuals. We then explored its link with the burden of deleterious mutations in a subset of individuals with available whole-genome sequencing data. To characterize the hypo/hyper-sensory profile, the differential Short Sensory Profile (dSSP) was defined as a normalized and centralized hypo/hypersensitivity ratio from the Short Sensory Profile (SSP). Including 1136 participants (533 autistic individuals, 210 first-degree relatives, and 267 controls) from two independent study samples (PARIS and LEAP), we observed a statistically significant dSSP mean difference between autistic individuals and controls, driven mostly by a high dSSP variability, with an intermediated profile represented by relatives. Our genetic analysis tended to associate the dSSP and the hyposensitivity with mutations of the GABAergic pathway. The major limitation was the dSSP difficulty to discriminate subjects with a similar quantum of hypo- and hyper-sensory symptoms to those with no such symptoms, resulting both in a similar ratio score of 0. However, the dSSP could be a relevant clinical score, and combined with additional sensory descriptions, genetics and endophenotypic substrates, will improve the exploration of the underlying neurobiological mechanisms of sensory processing differences in autism spectrum.

Self and caregiver report measurement of sensory features in autism spectrum disorder: a systematic review of psychometric properties

BACKGROUND

Unusual responses to sensory stimuli are considered a diagnostic symptom of autism spectrum disorder with mounting research efforts put towards understanding, characterizing, and treating such symptoms.

METHODS

This paper examines self and caregiver report tools used to measure sensory features in ASD through a systematic review of the psychometric evidence for their use. A total of 31 empirical papers were reviewed across 20 assessment tools. Substantial differences were identified in the specific sensory features defined across assessment tools. Sensory assessment questionnaires were evaluated against quality psychometric evidence criteria to provide a use recommendation.

RESULTS

Five assessments were identified to be "appropriate with conditions," while no sensory assessment tools were identified to have sufficient quality psychometric evidence to provide a recommendation of "Appropriate" for measuring sensory features in ASD.

CONCLUSION

Evidence from this review highlights potentially significant shortcomings among the current methods used to measure sensory features in ASD and suggests the need for more efforts in developing psychometrically sound sensory assessment tools for use in ASD populations.

Examining the Latent Structure and Correlates of Sensory Reactivity in Autism: A Multi-site Integrative Data Analysis by the Autism Sensory Research Consortium

Background Differences in responding to sensory stimuli, including sensory hyperreactivity (HYPER), hyporeactivity (HYPO), and sensory seeking (SEEK) have been observed in autistic individuals across sensory modalities, but few studies have examined the structure of these "supra-modal" traits in the autistic population. Methods Leveraging a combined sample of 3,868 autistic youth drawn from 12 distinct data sources (ages 3-18 years and representing the full range of cognitive ability), the current study used modern psychometric and meta-analytic techniques to interrogate the latent structure and correlates of caregiver-reported HYPER, HYPO, and SEEK within and across sensory modalities. Bifactor statistical indices were used to both evaluate the strength of a "general response pattern" factor for each supra-modal construct and determine the added value of "modality-specific response pattern" scores (e.g., Visual HYPER). Bayesian random-effects integrative data analysis models were used to examine the clinical and demographic correlates of all interpretable HYPER, HYPO and SEEK (sub)constructs. Results All modality-specific HYPER subconstructs could be reliably and validly measured, whereas certain modality-specific HYPO and SEEK subconstructs were psychometrically inadequate when measured using existing items. Bifactor analyses unambiguously supported the validity of a supra-modal HYPER construct (ω H  = .800), whereas a coherent supra-modal HYPO construct was not supported (ω H  = .611), and supra-modal SEEK models suggested a more limited version of the construct that excluded some sensory modalities (ω H  = .799; 4/7 modalities). Within each sensory construct, modality-specific subscales demonstrated substantial added value beyond the supra-modal score. Meta-analytic correlations varied by construct, although sensory features tended to correlate most strongly with other domains of core autism features and co-occurring psychiatric symptoms. Certain subconstructs within the HYPO and SEEK domains were also associated with lower adaptive behavior scores. Limitations: Conclusions may not be generalizable beyond the specific pool of items used in the current study, which was limited to parent-report of observable behaviors and excluded multisensory items that reflect many "real-world" sensory experiences. Conclusion Psychometric issues may limit the degree to which some measures of supra-modal HYPO/SEEK can be interpreted. Depending on the research question at hand, modality-specific response pattern scores may represent a valid alternative method of characterizing sensory reactivity in autism.

Effect of vibrostimulatory wearable technology on stereotyped behaviour in a child with autism and intellectual disability

The aim of the work has been to report on the effects of vibrostimulation, administered through wearable technology, on stereotyped behaviour of a child in middle childhood, with autism, intellectual disability and severe behaviour in the 'stereotypic behaviour' subscale of the Restricted and Repetitive Behaviour Revised Scale. He received vibrostimulation (210 Hz, 2.8 µm), with a continuous pattern of vibration: three vibrations of 700 ms, each separated by a rest period of 500 ms and a pause of 8000 ms. Vibration was delivered bilaterally by two devices, repeating the vibration pattern for 3 min. The measures were repeated four times alternately, with the device turned off and on. The outcome measure was frequency of stereotyed behaviour, which was evaluated for 3 min with and without vibrostimulation. The results and observations, over 3 min of stimulation, showed the disappearance of stereotyped movements during vibrostimulation and better precision in intentional hand movements. Subjectively, the child enjoyed vibrostimulation.

Brainstem white matter microstructure is associated with hyporesponsiveness and overall sensory features in autistic children

BACKGROUND

Elevated or reduced responses to sensory stimuli, known as sensory features, are common in autistic individuals and often impact quality of life. Little is known about the neurobiological basis of sensory features in autistic children. However, the brainstem may offer critical insights as it has been associated with both basic sensory processing and core features of autism.

METHODS

Diffusion-weighted imaging (DWI) and parent-report of sensory features were acquired from 133 children (61 autistic children with and 72 non-autistic children, 6-11 years-old). Leveraging novel DWI processing techniques, we investigated the relationship between sensory features and white matter microstructure properties (free-water-elimination-corrected fractional anisotropy [FA] and mean diffusivity [MD]) in precisely delineated brainstem white matter tracts. Follow-up analyses assessed relationships between microstructure and sensory response patterns/modalities and analyzed whole brain white matter using voxel-based analysis.

RESULTS

Results revealed distinct relationships between brainstem microstructure and sensory features in autistic children compared to non-autistic children. In autistic children, more prominent sensory features were generally associated with lower MD. Further, in autistic children, sensory hyporesponsiveness and tactile responsivity were strongly associated with white matter microstructure in nearly all brainstem tracts. Follow-up voxel-based analyses confirmed that these relationships were more prominent in the brainstem/cerebellum, with additional sensory-brain findings in the autistic group in the white matter of the primary motor and somatosensory cortices, the occipital lobe, the inferior parietal lobe, and the thalamic projections.

LIMITATIONS

All participants communicated via spoken language and acclimated to the sensory environment of an MRI session, which should be considered when assessing the generalizability of this work to the whole of the autism spectrum.

CONCLUSIONS

These findings suggest unique brainstem white matter contributions to sensory features in autistic children compared to non-autistic children. The brainstem correlates of sensory features underscore the potential reflex-like nature of behavioral responses to sensory stimuli in autism and have implications for how we conceptualize and address sensory features in autistic populations.

Re-Examining Labels in Neurocognitive Research: Evidence from Bilingualism and Autism as Spectrum-Trait Cases

Despite the fact that the urge to investigate bilingualism and neurodevelopmental disorders as continuous indices rather than categorical ones has been well-voiced among researchers with respect to research methodological approaches, in the recent literature, when it comes to examining language, cognitive skills and neurodivergent characteristics, it is still the case that the most prevalent view is the categorisation of adults or children into groups. In other words, there is a categorisation of individuals, e.g., monolingual vs. bilingual children or children with typical and atypical/non-typical/non-neurotypical development. We believe that this labelling is responsible for the conflicting results that we often come across in studies. The aim of this review is to bring to the surface the importance of individual differences through the study of relevant articles conducted in bilingual children and children with autism, who are ideal for this study. We concur with researchers who already do so, and we further suggest moving away from labels and instead shift towards the view that not everything is either white or black. We provide suggestions as to how this shift could be implemented in research, while mostly aiming at starting a discourse rather than offering a definite path.

A longitudinal exploratory study of changes in sensory processing in children with ASD from the ELENA cohort

Atypical sensory processing (SP) is a diagnostic criterion of autism spectrum disorder (ASD). However, little is known about its course during development. In this exploratory longitudinal study, we aimed to investigate the course of SP among children with ASD and identify clinical variables associated with changes. We used a subsample of 51 children with confirmed ASD, aged from 3 to 10 years, recruited from the ELENA cohort. SP was assessed using the Sensory Profile questionnaire at baseline and three years later. Our preliminary results highlight the heterogeneity of the evolution of SP during the children's development and the existence of three subgroups based on the course of SP (improvement, stable, and worsening). In addition, the children's adaptive skills and maladaptive behaviors were related to the course of SP. These results could be confirmed in future studies with a larger sample size using a longitudinal approach to capture individual variability in SP. In addition, our results highlight the importance of accounting for temporal changes in the sensory needs of individuals with ASD in clinical practice.

Exploring Effects of Sensory Garments on Participation of Children on the Autism Spectrum: A Pretest-Posttest Repeated Measure Design

Objective

Autistic children experience sensory challenges that interfere with participation and increase parent stress. Sensory-based interventions are used to address children's behaviors affected by sensory processing difficulties, but research is limited regarding use of sensory garments to support participation of autistic children. This study explored sensory garment effects on participation, parental competence, and perceived stress of autistic children and their parents.

Method

Twenty-one children were recruited and 17 males with ASD and atypical sensory processing patterns completed the 14-week study. The Canadian Occupational Performance (COPM) and Goal Attainment Scaling (GAS) were used to set and monitor participation goals. After a baseline period, children wore sensory garment(s) for 8 weeks. The COPM, GAS, Parent Stress Index-Short Form (PSI-SF), and Parent Sense of Competence Scale (PSOC) were administered four times (prebaseline, before and after the intervention, and three weeks postintervention).

Results

There were moderate to large significant differences in both COPM and GAS scores after the intervention and from the beginning to the end of the study indicating sensory garments may improve participation of autistic children. There were no significant differences in PSI or PSOC at any timepoint. Two children rejected the garments.

Conclusions

Parent- or child-selected sensory garments may improve participation in individually meaningful activities for children who can tolerate wearing them. Children's improvement in participation did not improve parent stress or competence, possibly due to the passive nature of the intervention. More research is needed explore the influence of heterogeneous sensory patterns on response to intervention.

A Multidimensional Investigation of Sensory Processing in Autism: Parent- and Self-Report Questionnaires, Psychophysical Thresholds, and Event-Related Potentials in the Auditory and Somatosensory Modalities

Background

Reconciling results obtained using different types of sensory measures is a challenge for autism sensory research. The present study used questionnaire, psychophysical, and neurophysiological measures to characterize autistic sensory processing in different measurement modalities.

Methods

Participants were 46 autistic and 21 typically developing 11- to 14-year-olds. Participants and their caregivers completed questionnaires regarding sensory experiences and behaviors. Auditory and somatosensory event-related potentials (ERPs) were recorded as part of a multisensory ERP task. Auditory detection, tactile static detection, and tactile spatial resolution psychophysical thresholds were measured.

Results

Sensory questionnaires strongly differentiated between autistic and typically developing individuals, while little evidence of group differences was observed in psychophysical thresholds. Crucially, the different types of measures (neurophysiological, psychophysical, questionnaire) appeared to be largely independent of one another. However, we unexpectedly found autistic participants with larger auditory Tb ERP amplitudes had reduced hearing acuity, even though all participants had hearing acuity in the non-clinical range.

Limitations

The autistic and typically developing groups were not matched on cognitive ability, although this limitation does not affect our main analyses regarding convergence of measures within autism.

Conclusion

Overall, based on these results, measures in different sensory modalities appear to capture distinct aspects of sensory processing in autism, with relatively limited convergence between questionnaires and laboratory-based tasks. Generally, this might reflect the reality that laboratory tasks are often carried out in controlled environments without background stimuli to compete for attention, a context which may not closely resemble the busier and more complex environments in which autistic people's atypical sensory experiences commonly occur. Sensory questionnaires and more naturalistic laboratory tasks may be better suited to explore autistic people's real-world sensory challenges. Further research is needed to replicate and investigate the drivers of the unexpected association we observed between auditory Tb ERP amplitudes and hearing acuity, which could represent an important confound for ERP researchers to consider in their studies.

Atypical sensory processing features in children with autism, and their relationships with maladaptive behaviors and caregiver strain

Atypical sensory processing occurs in up to 97% of children on the autism spectrum. Children who are on the autism spectrum also commonly demonstrate challenging behaviors, and their caregivers report increased levels of strain in daily life. The aim of this study was to explore four sensory processing features; seeking, avoiding, sensitivity, and registration, and their relationships with maladaptive behaviors in children with autism, as well as with caregiver strain. Participants comprised 75 children with autism aged 7–12 years (M = 7.81). Caregivers completed three questionnaire measures examining child sensory processing, maladaptive behaviors, and perceptions of caregiver strain. We found avoiding significantly associated with irritability. Avoiding also displayed the strongest relationship with global caregiver strain. Avoiding and seeking were strongly related to hyperactivity/noncompliance (components of maladaptive behavior). A multiple regression was performed to explore how atypical sensory processing features and maladaptive behaviors together predicted caregiver strain. Together, maladaptive behaviors and sensory features accounted for 58% of the variance in total caregiver strain. The only significant individual predictor of total caregiver strain was sensory avoiding, which uniquely accounted for 5.76% of the variation. The findings suggest that atypical sensory processing is associated with overall caregiver strain, above that explained by maladaptive behaviors. Implications for targeted support for the benefit of the child, parents and family unit are discussed.

Developmental trajectories of sensory patterns from infancy to school age in a community sample and associations with autistic traits

This prospective study examined the latent growth trajectories of sensory patterns among a North Carolina birth cohort (N = 1517; 49% boys, 87% White) across infancy (6-19 months), preschool (3-4 years), and school years (6-7 years). Change rates of sensory hyper- and hyporesponsiveness better differentiated children with an autism diagnosis or elevated autistic traits from those with other developmental conditions, including non-autistic children with sensory differences. More sensory hyper- and hyporesponsiveness at infancy followed by steeper increases differentially predicted more autistic traits at school age. Further, children of parents with higher education tended to show stable or improving trajectories. These findings highlight the importance of tracking sensory patterns from infancy for facilitating early identification of associated challenges and tailored support for families.

Interindividual Differences in Cortical Thickness and Their Genomic Underpinnings in Autism Spectrum Disorder

OBJECTIVE

Autism spectrum disorder (ASD) is accompanied by highly individualized neuroanatomical deviations that potentially map onto distinct genotypes and clinical phenotypes. This study aimed to link differences in brain anatomy to specific biological pathways to pave the way toward targeted therapeutic interventions.

METHODS

The authors examined neurodevelopmental differences in cortical thickness and their genomic underpinnings in a large and clinically diverse sample of 360 individuals with ASD and 279 typically developing control subjects (ages 6-30 years) within the EU-AIMS Longitudinal European Autism Project (LEAP). The authors also examined neurodevelopmental differences and their potential pathophysiological mechanisms between clinical ASD subgroups that differed in the severity and pattern of sensory features.

RESULTS

In addition to significant between-group differences in "core" ASD brain regions (i.e., fronto-temporal and cingulate regions), individuals with ASD manifested as neuroanatomical outliers within the neurotypical cortical thickness range in a wider neural system, which was enriched for genes known to be implicated in ASD on the genetic and/or transcriptomic level. Within these regions, the individuals' total (i.e., accumulated) degree of neuroanatomical atypicality was significantly correlated with higher polygenic scores for ASD and other psychiatric conditions, and it scaled with measures of symptom severity. Differences in cortical thickness deviations were also associated with distinct sensory subgroups, especially in brain regions expressing genes involved in excitatory rather than inhibitory neurotransmission.

CONCLUSIONS

The study findings corroborate the link between macroscopic differences in brain anatomy and the molecular mechanisms underpinning heterogeneity in ASD, and provide future targets for stratification and subtyping.

An German Short-Version of the "Sensory Perception Quotient" for Adults With Autism Spectrum Disorder

Sensory features in autism spectrum disorder (ASD) have received increasing interest in clinical work and research during the recent years. With the Sensory Perception Quotient (SPQ), Tavasolli and colleagues have produced a self-rating scale for adults with ASD that measures sensory hyper-sensitivity in different sensory modalities, without also tapping cognitive or motivational aspects that precede or follow autistic sensory experiences. Here, we present the results of a translation of the SPQ to German and its short version as well as their validation in samples of autistic or neuro-typical participants. We, furthermore, present the psychometric properties and validities of Tavasolli's original SPQ-short version as well as an alternative short version based on different psychometric item-selection criteria. We can show here that our alternative SPQ-short version, overlapping with the original short-version in 61% of its items, exhibits superior reliabilities, reasonable concurrent validities with other related measures. It, furthermore, exhibits excellent differentiation between autistic and non-autistic samples, underscoring its utility as a screening instrument in research and a clinical instrument to supplement the ASD diagnostic process.

Longitudinal Changes in Cortical Thickness in Adolescents with Autism Spectrum Disorder and Their Association with Restricted and Repetitive Behaviors

The neuroanatomy of autism spectrum disorder (ASD) shows highly heterogeneous developmental trajectories across individuals. Mapping atypical brain development onto clinical phenotypes, and establishing their molecular underpinnings, is therefore crucial for patient stratification and subtyping. In this longitudinal study we examined intra- and inter-individual differences in the developmental trajectory of cortical thickness (CT) in childhood and adolescence, and their genomic underpinnings, in 33 individuals with ASD and 37 typically developing controls (aged 11–18 years). Moreover, we aimed to link regional atypical CT development to intra-individual variations in restricted and repetitive behavior (RRB) over a two-year time period. Individuals with ASD showed significantly reduced cortical thinning in several of the brain regions functionally related to wider autism symptoms and traits (e.g., fronto-temporal and cingulate cortices). The spatial patterns of the neuroanatomical differences in CT were enriched for genes known to be associated with ASD at a genetic and transcriptomic level. Further, intra-individual differences in CT correlated with within-subject variability in the severity of RRBs. Our findings represent an important step towards characterizing the neuroanatomical underpinnings of ASD across development based upon measures of CT. Moreover, our findings provide important novel insights into the link between microscopic and macroscopic pathology in ASD, as well as their relationship with different clinical ASD phenotypes.

Exploring Sensory Subgroups in Typical Development and Autism Spectrum Development Using Factor Mixture Modelling

This study uses factor mixture modelling of the Short Sensory Profile (SSP) at two time points to describe subgroups of young autistic and typically-developing children. This approach allows separate SSP subscales to influence overall SSP performance differentially across subgroups. Three subgroups were described, one including almost all typically-developing participants plus many autistic participants. SSP performance of a second, largely-autistic subgroup was predominantly shaped by a subscale indexing behaviours of low energy/weakness. Finally, the third subgroup, again largely autistic, contained participants with low (or more “atypical”) SSP scores across most subscales. In this subgroup, autistic participants exhibited large P1 amplitudes to loud sounds. Autistic participants in subgroups with more atypical SSP scores had higher anxiety and more sleep disturbances.

Differentiation of autism spectrum disorder and mood or anxiety disorder

Autism spectrum disorder shares many symptoms with other mental health disorders, and comorbid disorders such as mood and anxiety disorders are common, making the diagnostic process challenging. We aimed to explore the diagnostic accuracy of two standard autism spectrum disorder diagnostic instruments and to identify those behavioral items that best differentiate between autism spectrum disorder and mood and anxiety disorder in a naturalistic sample of patients utilizing autism spectrum disorder specialist services. The study included data of 847 participants (5–65 years of age, n = 586 with autism spectrum disorder, n = 261 with mood and anxiety disorder) all evaluated with the Autism Diagnostic Observation Schedule in the context of the diagnostic process. Data of the Autism Diagnostic Interview–Revised were available for 428 participants (5–51 years of age, n = 367 with autism spectrum disorder, n = 61 with mood and anxiety disorder). By means of binominal logistic regressions and an ensemble feature selection, we identified a subset of items that best differentiated between autism spectrum disorder and mood and anxiety disorder. Overall, the results indicate that a combination of communicational deficits and unusual and/or inappropriate social overtures differentiates autism spectrum disorder and mood and anxiety disorder. Aspects of social cognition are also relevant. Limitations of the current study and implications for research and practice are discussed.

The impact of atypical sensory processing on adaptive functioning within and beyond autism: The role of familial factors

LAY ABSTRACT

Individuals diagnosed with autism tend to process sensory information differently than individuals without autism, resulting for instance in increased sensitivity to sounds or smells. This leads to challenges in everyday life and may restrict the individual's daily functioning. How direct this link is, however, is currently unclear. We investigated this question in 289 twins of whom 60 were diagnosed with autism and further 61 were diagnosed with other neurodevelopmental disorders. We looked at the association between unusual sensory processing and adaptive skills, both across individuals and within-twin pairs, testing whether individuals with higher levels of atypical sensory processing showed reduced adaptive skills compared to their twins. Since twins share 50%-100% of their genes and part of their environment (e.g. family background), associations within-twin pairs are free from effects of these familial factors. We found that an increased sensitivity to, as well as the avoiding of, sensory input (hyper-responsiveness) was linked to reduced adaptive skills across individuals-but not within-twin pairs. We also found an association between the degree to which individuals seek for sensory input (sensation seeking) and reduced adaptive skills, but only in individuals diagnosed with autism. The results suggest that sensory hyper-responsiveness has negative effects on individuals' general ability to function, but that this link is influenced by familial factors and hence not direct. In addition, sensation seeking behaviors might have a negative impact on adaptive skills specifically in autistic individuals.

Assessing general and autism-relevant quality of life in autistic adults: A psychometric investigation using item response theory

Although many interventions and services for autistic people have the ultimate goal of improving quality of life (QoL), there is relatively little research on how best to assess this construct in the autistic population, and existing scales designed for non-autistic individuals may not assess all meaningful facets of QoL in the autistic population. To address this need, the autism spectrum QoL form (ASQoL) was recently developed as a measure of the autism-relevant quality of life. However, the psychometrics of the ASQoL have not been examined beyond the authors' initial validation study, and important properties such as measurement invariance/differential item functioning (DIF) have not yet been tested. Using data from 700 autistic adults recruited from the Simons Foundation's SPARK cohort, the current study sought to perform a comprehensive independent psychometric evaluation of the ASQoL using item response theory, comparing its performance to a newly-proposed brief measure of general QoL (the WHOQOL-4). Our models revealed substantial DIF by sex and gender in the ASQoL, which caused ASQoL scores to grossly underestimate the self-reported QoL of autistic women. Based on a comparison of latent variable means, we demonstrated that observed sex/gender differences in manifest ASQoL scores were the result of statistical artifacts, a claim that was further supported by the lack of significant group differences on the sex/gender-invariant WHOQOL-4. Our findings indicate that the ASQoL composite score is psychometrically problematic in its current form, and substantial revisions may be necessary before valid and meaningful inferences can be made regarding autism-relevant aspects of QoL. LAY SUMMARY: Quality of life (QoL) is an extremely important outcome for autistic people, but many of the tools that are used to measure it does not take into account how QoL may be different for autistic people. Using data from 700 autistic adults, we examined the measurement properties of the autism spectrum quality of life form (ASQoL), a new measure of QoL designed specifically for autistic people. Our results indicate that the ASQoL shows a pronounced sex/gender bias, which causes it to underestimate QoL in autistic women. This bias needs to be eliminated before the ASQoL can be successfully used to measure QoL in the autistic population.

Using Clustering to Examine Inter-individual Variability in Topography of Auditory Event-Related Potentials in Autism and Typical Development

Although prior studies have compared sensory event-related potential (ERP) responses between groups of autistic and typically-developing participants, it is unclear how heterogeneity contributes to the results of these studies. The present study used examined individual differences in these responses. 130 autistic children and 81 typically-developing children, aged between 2 and 5 years, listened to tones at four identity levels while 61-channel electroencephalography was recorded. Hierarchical clustering was used to group participants based on rescaled ERP topographies between 51 and 350 ms. The hierarchical clustering analysis revealed substantial heterogeneity. Some of the seven clusters defined in this analysis were characterized by prolonged fronto-central positivities and/or weak or absent N2 negativities. However, many other participants fell into clusters in which N2 responses were present at varying latencies. Atypical response morphologies such as absent N2 responses and/or prolonged positive-going responses found in some autistic participants may account for prior research findings of attenuated N2 amplitudes in autism. However, there was also considerable overlap between groups, with participants of both groups appearing in all clusters. These results emphasize the utility of using clustering to explore individual differences in brain responses, which can expand on and clarify the results of analyses of group mean differences.

Sex differences in sensory processing in children with autism spectrum disorder

Despite the high prevalence of sensory processing difficulties in children with autism spectrum disorder (ASD), little research has focused on the sex differences in sensory processing. Furthermore, there is a lack of knowledge on the female‐specific symptoms of ASD, contributing to later referral, diagnosis and intervention. In this study, we examined the sex differences in sensory processing symptoms in large cohorts of ASD children (N = 168; 26 females, 142 males) and typically developing (TD) children (N = 439; 209 females, 230 males). For this, we translated the sensory processing measure (SPM) and SPM – Preschool (SPM‐P) Home Forms to French. The SPM/SPM‐P are parent/caregiver questionnaires that assess typical behavioral responses to sensory stimuli. Overall, our results showed that the magnitude of the differences in sensory processing between males and females is larger in ASD children relative to TD children, with females showing more severe symptoms in Hearing, as well as Balance and Motion subscales. Additionally, linear discriminant analysis showed that the SPM/SPM‐P are good at discriminating TD children from ASD, children with higher accuracy rates for females than for males. These findings are discussed in light of the heterogeneity of sensory processing difficulties present in ASD. Overall, our results suggest that there seem to be female‐specific profiles in sensory processing difficulties in ASD. Implications of findings concerning sex differences in sensory processing and their potential for improving identification and diagnosis of ASD females are discussed.

Selective Mutism and Its Relations to Social Anxiety Disorder and Autism Spectrum Disorder

In current classification systems, selective mutism (SM) is included in the broad anxiety disorders category. Indeed, there is abundant evidence showing that anxiety, and social anxiety in particular, is a prominent feature of SM. In this article, we point out that autism spectrum problems in addition to anxiety problems are sometimes also implicated in SM. To build our case, we summarize evidence showing that SM, social anxiety disorder (SAD), and autism spectrum disorder (ASD) are allied clinical conditions and share communalities in the realm of social difficulties. Following this, we address the role of a prototypical class of ASD symptoms, restricted and repetitive behaviors and interests (RRBIs), which are hypothesized to play a special role in the preservation and exacerbation of social difficulties. We then substantiate our point that SM is sometimes more than an anxiety disorder by addressing its special link with ASD in more detail. Finally, we close by noting that the possible involvement of ASD in SM has a number of consequences for clinical practice with regard to its classification, assessment, and treatment of children with SM and highlight a number of directions for future research.

COVID-19 health and social care access for autistic people: European policy review

BACKGROUND

The global COVID-19 pandemic has had an unprecedented impact on European health and social care systems, with demands on testing, hospital and intensive care capacity exceeding available resources in many regions. This has led to concerns that some vulnerable groups, including autistic people, may be excluded from services.

METHODS

We reviewed policies from 15 European member states, published in March-July 2020, pertaining to (1) access to COVID-19 tests; (2) provisions for treatment, hospitalisation and intensive care units (ICUs); and (3) changes to standard health and social care. In parallel, we analysed survey data on the lived experiences of 1301 autistic people and caregivers.

RESULTS

Autistic people experienced significant barriers when accessing COVID-19 services. First, despite being at elevated risk of severe illness due to co-occurring health conditions, there was a lack of accessibility of COVID-19 testing. Second, many COVID-19 outpatient and inpatient treatment services were reported to be inaccessible, predominantly resulting from individual differences in communication needs. Third, ICU triage protocols in many European countries (directly or indirectly) resulted in discriminatory exclusion from lifesaving treatments. Finally, interruptions to standard health and social care left over 70% of autistic people without everyday support.

CONCLUSIONS

The COVID-19 pandemic has further exacerbated existing healthcare inequalities for autistic people, probably contributing to disproportionate increases in morbidity and mortality, mental health and behavioural difficulties, and reduced quality of life. An urgent need exists for policies and guidelines on accessibility of COVID-19 services to be updated to prevent the widespread exclusion of autistic people from services, which represents a violation of international human rights law.

Two Faces of a Coin? A Systematic Review of Source Monitoring and Its Relationship with Memory in Autism

The ability to discriminate the origin of stimuli, known as source monitoring, is crucial for self–other distinction and the integration of internally generated and externally generated experiences. Despite its valence, evidence on source monitoring in autism is yet scarce and unclear. We systematically reviewed literature concerning source monitoring in autism and its relationship with other constructs, such as memory type, encoding effects, social cognition, general intelligence, and clinical factors. Source-monitoring performance (operationalized as error or accuracy) was reduced in autistic participants in 9 of the 15 studies that met the inclusion criteria. When explicitly investigated, free-recall memory impairments in autism were shown to influence source monitoring deficits. General intelligence was another important factor linked to source-monitoring performance. Conversely, other memory types or encoding effects were not impaired in autism, and no univocal association could be found with source monitoring. Social cognition and clinical symptoms were rarely assessed in spite of their possible involvement in source monitoring. The heterogeneity of the task design, outcome measures and demographical factors limited study comparability. As a research framework on source monitoring as a construct of primary interest in autism is still lacking, we propose preliminary indications for future investigations based on the collected findings.

[Far beyond nutrients: experiences and connections with autistic children based on cooking and sharing meals]

This study examined ways to expand the analysis of diet in autistic children, widely considered inadequate according to food selectivity and/or difficulty interacting at mealtimes, attributed to alterations in sensorial processing and social, communicative, and cognitive difficulties. From an ethnographic perspective, a participant observational study was performed with field diary records and cooking workshops with autistic children and adolescents, aimed at analyzing the relations established by the children with the food and utensils, physical space, and between each other and the adults. The records were analyzed based on Bondía's notion of experience and Actor-Network Theory. The resulting data showed singularities in performing cooking tasks and accepting recipes. Some children did not eat the foods, but smelled, licked, and handled the ingredients in moments of experimentation through mediation by the educators, facilitating connection by the children with food and eating. The interactions established with foods and utensils highlight the importance of food and eating as mediators of the connection between autistic children and their peers, with adults, and with the world. This experience broke with the homogenizing value assigned to autistic children's difficulties with interaction and reinforced commensality as a tool for building networks of care. To conceive eating for these children from an expanded perspective means to value subjectivity, the relationship to food, and interaction with others at mealtimes, far beyond the biological understanding of the nutrients.

Touch and olfaction/taste differentiate children carrying a 16p11.2 deletion from children with ASD

Background

Sensory processing atypicalities are frequent in Autism Spectrum Disorder (ASD) and neurodevelopmental disorders (NDD). Different domains of sensory processing appear to be differentially altered in these disorders. In this study, we explored the sensory profile of two clinical cohorts, in comparison with a sample of typically developing children.

Methods

Behavioral responses to sensory stimuli were assessed using the Sensory Processing Measure (parent-report questionnaire). We included 121 ASD children, 17 carriers of the 16p11.2 deletion (Del 16p11.2) and 45 typically developing (TD) children. All participants were aged between 2 and 12 years. Additional measures included the Tactile Defensiveness and Discrimination Test-Revised, Wechsler Intelligence Scales and Autism Diagnostic Observation Schedule (ADOS-2). Statistical analyses included MANCOVA and regression analyses.

Results

ASD children score significantly higher on all SPM subscales compared to TD. Del16p11.2 also scored higher than TD on all subscales except for tactile and olfactory/taste processing, in which they score similarly to TD. When assessing sensory modulation patterns (hyper-, hypo-responsiveness and seeking), ASD did not significantly differ from del16p11.2. Both groups had significantly higher scores across all patterns than the TD group. There was no significant association between the SPM Touch subscale and the TDDT-R.

Limitations

Sensory processing was assessed using a parent-report questionnaire. Even though it captures observable behavior, a questionnaire does not assess sensory processing in all its complexity. The sample size of the genetic cohort and the small subset of ASD children with TDDT-R data render some of our results exploratory. Divergence between SPM Touch and TDDT-R raises important questions about the nature of the process that is assessed.

Conclusions

Touch and olfaction/taste seem to be particularly affected in ASD children compared to del16p11.2. These results indicate that parent report measures can provide a useful perspective on behavioral expression. Sensory phenotyping, when combined with neurobiological and psychophysical methods, might have the potential to provide a better understanding of the sensory processing in ASD and in other NDD.

Somatosensory Temporal Discrimination in Autism Spectrum Disorder

Sensory differences are common in Autism Spectrum Disorder (ASD). While there is no well-accepted method to measure sensory differences objectively, there is accumulating evidence from recent years concerning sensory perception, including data concerning temporal discrimination thresholds of individuals with ASD as measured by different measures. The somatosensory temporal discrimination (STD) test measures the threshold at which an individual can temporally discriminate multiple tactile stimuli delivered in succession. We aimed to investigate tactile perception in ASD and hypothesized that children with ASD have impaired STD related to their subjective sensory symptoms and daily difficulties. Thirty adolescents with ASD and 30 typically developed subjects were recruited. The Childhood Autism Rating Scale, Strengths and Difficulties Questionnaire, and Adolescent/Adult Sensory Profile were implemented before STD evaluation. Average somatosensory detection (1.48 ± 0.42) and discrimination thresholds (112.70 ± 43.45) of the children with ASD were significantly higher (P = 0.010, P = 0.001, respectively) than those of the controls (1.18 ± 0.42, 79.95 ± 31.60, respectively). Sensory seeking scores of the ASD group (40.8 ± 7.60) were significantly lower (P = 0.024) than those of the control group (45.83 ± 9.17). However, the psychophsycal thresholds did not have any statistically significant relationships with subjective sensory symptoms or daily difficulties. This study demonstrates impaired sensory processing in ASD evaluated by STD and its lack of relationship with subjective sensory symptoms and daily difficulties. This psychophysical evidence of increased STD thresholds and decreased sensory seeking profile supports the disturbances in the regulation of sensory processing in ASD. LAY SUMMARY: Sensory differences are common in autism; however, there is no well-accepted method to measure them objectively. This study aims to investigate somatosensory differences and their relation with sensory and emotional/behavioral difficulties of children with autism. We show that autistic children have higher tactile discrimination thresholds and fewer sensory seeking behaviors. This supports the presence of impairments in sensory processing in autism. Measuring the sensory differences may help understanding clinical symptoms and neurobiological underpinings of autism. Autism Res 2021, 14: 656-667. © 2021 International Society for Autism Research and Wiley Periodicals LLC.

A review of decreased sound tolerance in autism: Definitions, phenomenology, and potential mechanisms

Atypical behavioral responses to environmental sounds are common in autistic children and adults, with 50-70 % of this population exhibiting decreased sound tolerance (DST) at some point in their lives. This symptom is a source of significant distress and impairment across the lifespan, contributing to anxiety, challenging behaviors, reduced community participation, and school/workplace difficulties. However, relatively little is known about its phenomenology or neurocognitive underpinnings. The present article synthesizes a large body of literature on the phenomenology and pathophysiology of DST-related conditions to generate a comprehensive theoretical account of DST in autism. Notably, we argue against conceptualizing DST as a unified construct, suggesting that it be separated into three phenomenologically distinct conditions: hyperacusis (the perception of everyday sounds as excessively loud or painful), misophonia (an acquired aversive reaction to specific sounds), and phonophobia (a specific phobia of sound), each responsible for a portion of observed DST behaviors. We further elaborate our framework by proposing preliminary neurocognitive models of hyperacusis, misophonia, and phonophobia that incorporate neurophysiologic findings from studies of autism.

Motor functioning in developmental psychopathology: A review of autism as an example context

BACKGROUND

Motor development research has seen substantial recent growth. However, much remains to be understood about the nature and extent of motor impairments in neurodevelopmental disorders, including their potential as early markers and/or causal determinants of downstream functioning in other domains.

AIMS AND METHODS

In this narrative review, drawing primarily on the autism literature by way of example, we review current accounts of the nature and consequences of motor functioning. We consider conventional approaches to measurement and study design, and current limited approaches to tackling heterogeneity.

CONCLUSIONS AND IMPLICATIONS

We argue that ongoing adherence to traditional diagnostic outcome classification stands in the face of mounting evidence that characteristics of neurodevelopmental disorders lie on a continuum with variability in the general population, and that three broad research avenues stand to offer a better understanding of motor functioning: The use of technology and advanced statistical methods for a more nuanced understanding of motor abilities; exploiting the prospective longitudinal tracking of at-risk infants to understand developmental consequences of early motor difference; and employing randomized controlled trials to test the utility of motor therapies whilst also testing causal hypotheses about the role of motor functioning.

The autism advantage at work: A critical and systematic review of current evidence

BACKGROUND

Despite difficulties entering the workforce, people on the autism spectrum are often successful. Furthermore, they are suggested to bring unique abilities (e.g., attention to detail, tolerance for repetitive tasks) related to the repetitive and restrictive behaviours and interests (RRBI) diagnostic domain, that may be advantageous in employment.

AIMS

This critical and systematic review examined evidence supporting the superior workplace performance of employees on the autism spectrum, particularly regarding the RRBI domain.

METHOD AND PROCEDURES

A systematic review (PRISMA guidelines) evaluated empirical peer-reviewed studies that assess employees on the autism spectrum's performance in the workplace or on work-specific tasks. Nine databases were searched, with additional papers identified from reference lists and consultation.

OUTCOMES AND RESULTS

Two quantitative and four qualitative papers met criteria. Results reflect themes; attention to detail, tolerance of repetitive tasks, special/circumscribed interests, other RRBI related advantages/concerns.

CONCLUSIONS AND IMPLICATIONS

Due to the nature and quality of the identified studies there is currently no strong evidence supporting or negating a workplace autism advantage. This review highlights the need for more research and urges constraint in utilising stereotypes that may not apply to all on the autism spectrum, arguing an individual differences approach to supporting autism strengths at work.

Identification of Longitudinal Sensory Subtypes in Typical Development and Autism Spectrum Development Using Growth Mixture Modelling

BACKGROUND

Prior longitudinal investigations of trajectories of sensory features in Autism Spectrum Development (ASD) have not explored heterogeneity. The present study explores initial levels and trajectories of sensory features in ASD as well as, for comparison, typical development.

METHOD

Growth mixture modelling was used to explore classes of autistic and typically-developing participants based on caregiver-reported total sensory behaviours on the Short Sensory Profile (SSP) at two time points, when children were aged 2-5 and 4-10 years of age, respectively.

RESULTS

Three classes are described: a mixed class of autistic and typically-developing participants with few problematic sensory behaviours ("Stable Mild"), a mostly-autistic class with more problematic sensory features ("Stable Intense"), and a small class of autistic participants whose sensory features reportedly worsened ("Increasingly Intense"). Autistic participants in the Stable Intense class exhibited high anxiety, while autistic participants in the Increasingly Intense class appeared to obtain high scores on cognitive assessments.

CONCLUSIONS

The heterogeneity of sensory features and challenges found in the present study may suggest that practitioners should conduct individualized assessments of sensory features in ASD. Furthermore, practitioners should be aware of links between sensory features and anxiety in ASD, which may imply that sensory accommodations and supports could protect against anxiety. Finally, the worsening of sensory features over time in the Increasingly Intense subgroup may indicate a need for continued monitoring of changes in sensory features, perhaps especially as sensory environments change during periods of transition.

Dissecting the phenotypic heterogeneity in sensory features in autism spectrum disorder: a factor mixture modelling approach

BACKGROUND

Heterogeneity in the phenotypic presentation of autism spectrum disorder (ASD) is apparent in the profile and the severity of sensory features. Here, we applied factor mixture modelling (FMM) to test a multidimensional factor model of sensory processing in ASD. We aimed to identify homogeneous sensory subgroups in ASD that differ intrinsically in their severity along continuous factor scores. We also investigated sensory subgroups in relation to clinical variables: sex, age, IQ, social-communication symptoms, restricted and repetitive behaviours, adaptive functioning and symptoms of anxiety and attention-deficit/hyperactivity disorder.

METHODS

Three hundred thirty-two children and adults with ASD between the ages of 6 and 30 years with IQs varying between 40 and 148 were included. First, three different confirmatory factor models were fit to the 38 items of the Short Sensory Profile (SSP). Then, latent class models (with two-to-six subgroups) were evaluated. The best performing factor model, the 7-factor structure, was subsequently used in two FMMs that varied in the number of subgroups: a two-subgroup, seven-factor model and a three-subgroup and seven-factor model.

RESULTS

The 'three-subgroup/seven-factor' FMM was superior to all other models based on different fit criteria. Identified subgroups differed in sensory severity from severe, moderate to low. Accounting for the potential confounding effects of age and IQ, participants in these sensory subgroups had different levels of social-communicative symptoms, restricted and repetitive behaviours, adaptive functioning skills and symptoms of inattention and anxiety.

LIMITATIONS

Results were derived using a single parent-report measure of sensory features, the SSP, which limits the generalisability of findings.

CONCLUSION

Sensory features can be best described by three homogeneous sensory subgroups that differ in sensory severity gradients along seven continuous factor scores. Identified sensory subgroups were further differentiated by the severity of core and co-occurring symptoms, and level of adaptive functioning, providing novel evidence on the associated clinical correlates of sensory subgroups. These sensory subgroups provide a platform to further interrogate the neurobiological and genetic correlates of altered sensory processing in ASD.

Autism Adversely Affects Auditory Joint Engagement During Parent-toddler Interactions

This study documents the early adverse effects of autism spectrum disorder (ASD) on auditory joint engagement-the sharing of sounds during interactions. A total of 141 toddlers (49 typically developing [TD], 46 with ASD, and 46 with non-ASD developmental disorders [DD]; average age 22.6 months) were observed during a semi-naturalistic play session with a parent. Reactions to four types of sounds-speech about the child, instrumental music, animal calls, and mechanical noises-were observed before and as parents tried to scaffold joint engagement with the sound. Toddlers with ASD usually appeared aware of a new sound, often alerting to and orienting toward it. But compared to TD toddlers and toddlers with DD, they alerted and oriented less often to speech, a difference not found with the other sounds. Furthermore, toddlers with ASD were far less likely to spontaneously try to share the sound with the parents and to engage with the parent and the sound when parents tried to share it with them. These findings reveal how ASD can have significant effects on shared experiences with nonvisible targets in the environment that attract toddlers' attention. Future studies should address the association between auditory joint engagement difficulties and variations in multimodal joint engagement, sensory profiles, and ASD severity and the reciprocal influence over time of auditory joint engagement experience and language development. LAY SUMMARY: Like most toddlers, toddlers with autism spectrum disorder often alert when they hear sounds like a cat's meow or a train's rumble. But they are less likely to alert when they hear their own name, and they are far less likely to share new sounds with their parents. These findings raise important questions about how toddlers with autism spectrum disorder experience their everyday auditory world, including how they share it with parents who can enrich this experience.

Defining clusters of young autistic and typically developing children based on loudness-dependent auditory electrophysiological responses

BACKGROUND

Autistic individuals exhibit atypical patterns of sensory processing that are known to be related to quality of life, but which are also highly heterogeneous. Previous investigations of this heterogeneity have ordinarily used questionnaires and have rarely investigated sensory processing in typical development (TD) alongside autism spectrum development (ASD).

METHODS

The present study used hierarchical clustering in a large sample to identify subgroups of young autistic and typically developing children based on the normalized global field power (GFP) of their event-related potentials (ERPs) to auditory stimuli of four different loudness intensities (50, 60, 70, 80 dB SPL): that is, based on an index of the relative strengths of their neural responses across these loudness conditions.

RESULTS

Four clusters of participants were defined. Normalized GFP responses to sounds of different intensities differed strongly across clusters. There was considerable overlap in cluster assignments of autistic and typically developing participants, but autistic participants were more likely to display a pattern of relatively linear increases in response strength accompanied by a disproportionately strong response to 70 dB stimuli. Autistic participants displaying this pattern trended towards obtaining higher scores on assessments of cognitive abilities. There was also a trend for typically developing participants to disproportionately fall into a cluster characterized by disproportionately/nonlinearly strong 60 dB responses. Greater auditory distractibility was reported among autistic participants in a cluster characterized by disproportionately strong responses to the loudest (80 dB) sounds, and furthermore, relatively strong responses to loud sounds were correlated with auditory distractibility. This appears to provide evidence of coinciding behavioral and neural sensory atypicalities.

LIMITATIONS

Replication may be needed to verify exploratory results. This analysis does not address variability related to classical ERP latencies and topographies. The sensory questionnaire employed was not specifically designed for use in autism. Hearing acuity was not measured. Variability in sensory responses unrelated to loudness is not addressed, leaving room for additional research.

CONCLUSIONS

Taken together, these data demonstrate the broader benefits of using electrophysiology to explore individual differences. They illuminate different neural response patterns and suggest relationships between sensory neural responses and sensory behaviors, cognitive abilities, and autism diagnostic status.

Language Performance in Preschool-Aged Boys with Nonsyndromic Autism Spectrum Disorder or Fragile X Syndrome

In the present study, language performance on standardized assessments (e.g., overall verbal performance, receptive and expressive vocabulary) and spontaneous language produced in play was compared between preschool-aged boys with autism spectrum disorder (nASD, n = 25) and boys with fragile X syndrome (FXS, n = 16). At the group-level, we observed weaknesses in the language skills of boys with nASD relative to those with FXS (e.g., when considering raw score performance, standard score performance relative to nonverbal cognitive skills, frequency of talk in play), after controlling for nonverbal IQ and ASD symptom severity. Moreover, although individually most children in both groups demonstrated language delays relative to CA-expectations, language delays relative to nonverbal level-expectations were more common in boys with nASD.