Annual Research Review: Understudied populations within the autism spectrum - current trends and future directions in neuroimaging research

In vivo translocator protein in females with autism spectrum disorder: a pilot study

Sex-based differences in the prevalence of autism spectrum disorder (ASD) are well-documented, with a male-to-female ratio of approximately 4:1. The clinical presentation of the core symptoms of ASD can also vary between sexes. Previously, positron emission tomography (PET) studies have identified alterations in the in vivo levels of translocator protein (TSPO)-a mitochondrial protein-in primarily or only male adults with ASD, with our group reporting lower TSPO relative to whole brain mean in males with ASD. However, whether in vivo TSPO levels are altered in females with ASD, specifically, is unknown. This is the first pilot study to measure in vivo TSPO in the brain in adult females with ASD using [11C]PBR28 PET-magnetic resonance imaging (MRI). Twelve adult females with ASD and 10 age- and TSPO genotype-matched controls (CON) completed one or two [11C]PBR28 PET-MRI scans. Females with ASD exhibited elevated [11C]PBR28 standardized uptake value ratio (SUVR) in the midcingulate cortex and splenium of the corpus callosum compared to CON. No brain area showed lower [11C]PBR28 SUVR in females with ASD compared to CON. Test-retest over several months showed stable [11C]PBR28 SUVR across time in both groups. Elevated regional [11C]PBR28 SUVR in females with ASD stand in stark contrast to our previous findings of lower regional [11C]PBR28 SUVR in males with ASD. Preliminary evidence of regionally elevated mitochondrial protein TSPO relative to whole brain mean in ASD females may reflect neuroimmuno-metabolic alterations specific to females with ASD.

Profiles of minimally verbal autistic children: Illuminating the neglected end of the spectrum

Heterogeneity among individuals on the autism spectrum is widely acknowledged as a barrier to develop effective interventions. Overcoming this challenge requires characterization of individual differences, especially for children that are minimally verbal and often excluded from research studies. Most studies that describe autistic subgroups identify a single minimally verbal verbal group based on a single identifying measure (e.g., ADOS module one or single item indicating absence of phrase speech). Determining personalized courses of intervention requires a more detailed understanding since a single intervention will not be effective for all who are minimally verbal. The present study identified comprehensive profiles of cognitive, language, and social communication skills within a large, diverse, group of minimally verbal children with autism. The analysis combined baseline data from two studies to yield a sample of 344 participants, who were 3 to 8 years old at the time of study onset, with 60% who identified as having a race/ethnicity other than White. Via latent profile analysis (LPA), a three-group model was identified as best fit to the data. Profile identification was dependent on a participant's combination of cognitive, expressive, and social communication characteristics, rather than a single domain. One group (n = 206) had global delays, while the other two groups (n = 95 and n = 43) had variable strengths in cognition and communication. Findings suggest that low-frequency/minimally verbal communicators with autism have heterogeneous characteristics that can be systematically organized.

Associations between Social Experiences and Psychological Health for Autistic Youth with Low IQ

PURPOSE

Social experiences are consistently associated with psychological health among autistic individuals. However, most extant studies on this topic exclude individuals with autism who have lower IQ or are otherwise unable to self-report. The current study addresses this gap by examining associations of negative peer experiences and social participation with psychological health among autistic youth with low IQ.

METHODS

An online survey was collected from 268 parents of autistic adolescents and adults ages 15-25. Negative peer experiences included measures of peer victimization and being ignored. Social participation was assessed by the amount of participation and parents' perceptions of whether their youth felt the amount of participation was meeting their needs. Psychological health was assessed by parents' report of their youth's psychological quality of life, as well as whether they felt their son/daughter was currently depressed.

RESULTS

Results suggested low rates of social participation in this sample, with relatively high rates of being ignored. Regression analysis found that lower rates of peer victimization and more activities in which parents perceived that the amount of time was meeting their youth's needs was associated with higher psychological quality of life and lower likelihood that parents felt their son/daughter was depressed.

CONCLUSION

Though youth with autism and low IQ are often excluded from interventions aimed at improving social experiences, these findings suggest that promoting positive social experiences and ameliorating negative ones might be an avenue to improving psychological health in this group.

The latent structure of the Delis-Kaplan system for autism

A core feature of autism is deficits in executive functioning (EF), including difficulty with planning, cognitive flexibility, and working memory. Despite a growing need for evidence-based assessments of EF for autism populations, statistical models of many commonly used measures of EF, including the Delis-Kaplan Executive Function System (D-KEFS), have not been investigated for a sample of autistic participants. The purpose of this study was to address a gap in the literature regarding the latent structure of the D-KEFS in a sample of autistic individuals. The D-KEFS is one of the most widely used clinical assessments of executive function, but its factor structure has not been examined in a sample of autistic participants. Reliability analyses were performed for sample subgroups based on participants' clinical and demographic characteristics, including IQ, autism severity, age, and race/ethnicity. Verbal Fluency (VF) was found to consistently decrease or not affect the overall reliability score. Additionally, one- and two-factor structure models were tested for the D-KEFS with a sample of autistic participants. The one-factor model was not found to be a good fit for the data. However, the two-factor model, with Cognitive Flexibility and Abstraction latent factors, was found to fit the data relatively well. This two-factor model was reexamined excluding the VF observed variable, resulting in a better overall model fit. Communication deficits are a common feature of autism, which explains why the VF task, that requires participants to produce novel words, may not be an adequate measure of executive function for autism populations.

Vowel distinctiveness as a concurrent predictor of expressive language function in autistic children

Speech ability may limit spoken language development in some minimally verbal autistic children. In this study, we aimed to determine whether an acoustic measure of speech production, vowel distinctiveness, is concurrently related to expressive language (EL) for autistic children. Syllables containing the vowels [i] and [a] were recorded remotely from 27 autistic children (4;1-7;11) with a range of spoken language abilities. Vowel distinctiveness was calculated using automatic formant tracking software. Robust hierarchical regressions were conducted with receptive language (RL) and vowel distinctiveness as predictors of EL. Hierarchical regressions were also conducted within a High EL and a Low EL subgroup. Vowel distinctiveness accounted for 29% of the variance in EL for the entire group, RL for 38%. For the Low EL group, only vowel distinctiveness was significant, accounting for 38% of variance in EL. Conversely, in the High EL group, only RL was significant and accounted for 26% of variance in EL. Replicating previous results, speech production and RL significantly predicted concurrent EL in autistic children, with speech production being the sole significant predictor for the Low EL group and RL the sole significant predictor for the High EL group. Further work is needed to determine whether vowel distinctiveness longitudinally, as well as concurrently, predicts EL. Findings have important implications for the early identification of language impairment and in developing language interventions for autistic children.

Predicting Problematic Behavior in Autism Spectrum Disorder Using Medical History and Environmental Data

Autism spectrum disorder (ASD), characterized by social, communication, and behavioral abnormalities, affects 1 in 36 children according to the CDC. Several co-occurring conditions are often associated with ASD, including sleep and immune disorders and gastrointestinal (GI) problems. ASD is also associated with sensory sensitivities. Some individuals with ASD exhibit episodes of challenging behaviors that can endanger themselves or others, including aggression and self-injurious behavior (SIB). In this work, we explored the use of artificial intelligence models to predict behavior episodes based on past data of co-occurring conditions and environmental factors for 80 individuals in a residential setting. We found that our models predict occurrences of behavior and non-behavior with accuracies as high as 90% for some individuals, and that environmental, as well as gastrointestinal, factors are notable predictors across the population examined. While more work is needed to examine the underlying connections between the factors and the behaviors, having reasonably accurate predictions for behaviors has the potential to improve the quality of life of some individuals with ASD.

The Predictive Relationship Between Sensory Reactivity and Depressive Symptoms in Young Autistic Children with Few to No Words

Depression and sensory reactivity are both common in autism. However, there is little understanding of the predictive relationship between these factors, or the nature of this relationship in autistic children who speak few to no words. This study set out to explore the longitudinal relationship between sensory reactivity and depressive symptoms in 33 young autistic children who speak few to no words. We found positive correlations between depressive symptoms and hyper-reactivity and sensory seeking at both timepoints, and across timepoints. We further found a bidirectional predictive relationship between depressive symptoms and sensory seeking. These results implicate sensory seeking in the development of depressive symptoms in young autistic children who use few to no words. Our findings have important implications for preventative mental health interventions, especially for those with a developmental language delay.

Brain-Computer Interface Training of mu EEG Rhythms in Intellectually Impaired Children with Autism: A Feasibility Case Series

Prior studies show that neurofeedback training (NFT) of mu rhythms improves behavior and EEG mu rhythm suppression during action observation in children with autism spectrum disorder (ASD). However, intellectually impaired persons were excluded because of their behavioral challenges. We aimed to determine if intellectually impaired children with ASD, who were behaviorally prepared to take part in a mu-NFT study using conditioned auditory reinforcers, would show improvements in symptoms and mu suppression following mu-NFT. Seven children with ASD (ages 6-8; mean IQ 70.6 ± 7.5) successfully took part in mu-NFT. Four cases demonstrated positive learning trends (hit rates) during mu-NFT (learners), and three cases did not (non-learners). Artifact-creating behaviors were present during tests of mu suppression for all cases, but were more frequent in non-learners. Following NFT, learners showed behavioral improvements and were more likely to show evidence of a short-term increase in mu suppression relative to non-learners who showed little to no EEG or behavior improvements. Results support mu-NFT's application in some children who otherwise may not have been able to take part without enhanced behavioral preparations. Children who have more limitations in demonstrating learning during NFT, or in providing data with relatively low artifact during task-dependent EEG tests, may have less chance of benefiting from mu-NFT. Improving the identification of ideal mu-NFT candidates, mu-NFT learning rates, source analyses, EEG outcome task performance, population-specific artifact-rejection methods, and the theoretical bases of NFT protocols, could aid future BCI-based, neurorehabilitation efforts.

Linguistic markers of autism spectrum conditions in narratives: A comprehensive analysis

Background & Aims: Narratives are regularly elicited as part of standardized assessments for autism spectrum conditions (ASC) such as the ADOS, but have rarely been utilized as linguistic data in their own right. We here aimed for a specific and comprehensive quantitative linguistic profile of such narratives across nominal, verbal, and clausal domains of grammatical organization, and error patterns. Methods: We manually transcribed and annotated narratives elicited from the ADOS from a sample of bilingual autistic Spanish-Catalan children (n = 18), matched with typically developing controls (n = 18) on vocabulary-based verbal IQ. Results: Results revealed fewer relative clauses and more frequent errors in referential specificity and non-relational content-word choice in ASC. Frequent error types are also discussed qualitatively. Conclusions & Implications: These findings, based on more finegrained linguistically defined variables, help to disentangle previous inconsistencies in the literature, and to better situate language changes in the spectrum of neurocognitive changes in this population.

Overview of Services for Autism Spectrum Disorders (ASD) in Low- and Middle-Income Countries (LMICs) and among Immigrants and Minority Groups in High-Income Countries (HICs)

Autism spectrum disorder (ASD) prevalence is rising [...].

Default mode and fronto-parietal network associations with IQ development across childhood in autism

Background

Intellectual disability affects approximately one third of individuals with autism spectrum disorder (autism). Yet, a major unresolved neurobiological question is what differentiates autistic individuals with and without intellectual disability. Intelligence quotients (IQs) are highly variable during childhood. We previously identified three subgroups of autistic children with different trajectories of intellectual development from early (2–3½ years) to middle childhood (9–12 years): (a) persistently high: individuals whose IQs remained in the normal range; (b) persistently low: individuals whose IQs remained in the range of intellectual disability (IQ < 70); and (c) changers: individuals whose IQs began in the range of intellectual disability but increased to the normal IQ range. The frontoparietal (FPN) and default mode (DMN) networks have established links to intellectual functioning. Here, we tested whether brain regions within the FPN and DMN differed volumetrically between these IQ trajectory groups in early childhood.

Methods

We conducted multivariate distance matrix regression to examine the brain regions within the FPN (11 regions x 2 hemispheres) and the DMN (12 regions x 2 hemispheres) in 48 persistently high (18 female), 108 persistently low (32 female), and 109 changers (39 female) using structural MRI acquired at baseline. FPN and DMN regions were defined using networks identified in Smith et al. (Proc Natl Acad Sci U S A 106:13040–5, 2009). IQ trajectory groups were defined by IQ measurements from up to three time points spanning early to middle childhood (mean age time 1: 3.2 years; time 2: 5.4 years; time 3: 11.3 years).

Results

The changers group exhibited volumetric differences in the DMN compared to both the persistently low and persistently high groups at time 1. However, the persistently high group did not differ from the persistently low group, suggesting that DMN structure may be an early predictor for change in IQ trajectory. In contrast, the persistently high group exhibited differences in the FPN compared to both the persistently low and changers groups, suggesting differences related more to concurrent IQ and the absence of intellectual disability.

Conclusions

Within autism, volumetric differences of brain regions within the DMN in early childhood may differentiate individuals with persistently low IQ from those with low IQ that improves through childhood. Structural differences in brain networks between these three IQ-based subgroups highlight distinct neural underpinnings of these autism sub-phenotypes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11689-022-09460-y.

Language level predicts perceptual categorization of complex reversible events in children

Language plays a well-documented role in perceptual object categorization, but little is known about its role in the categorization of complex events. We explored this here with a perspective from age or developmentally appropriate language capacities in neurotypical children between the ages of two and four years (N = 21), and from delayed language development in a clinical group of children (N = 20), whose verbal mental ages (VMA) often fell far below their chronological ages (CAs). All participants watched two demonstrations of a series of transitive events (e.g. tiger jumps over a girl). The toy agents were then moved out of sight, and participants had to act out the same event type, based on a different tiger and girl that were selected among two distractors. We aimed to determine how mastery of this task relates to CA in the neurotypical group, and whether task performance in the clinical group was predicted by VMA and a standardized measure of grammatical comprehension. Results from a series of logistic mixed-effect regression models showed that neurotypical children start to perform correctly on this task with a chance of around 50% during their third year of CA but reach ceiling performance only during their fourth. A similar pattern emerged for VMA in the clinical group, despite a wide range of CAs and diagnoses. In addition, grammatical comprehension predicted performance. These patterns suggest that language competence plays a role in the perceptual categorization and encoding of complex reversible events.

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Mental representations of complex event types were investigated.

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An event imitation task was used in children with and without language disorders.

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Chronological age and verbal mental age both predicted performance.

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Grammatical comprehension in the clinical group did as well.

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Cognizing complex events may be linguistically conditioned.

Verbal Ability, Behavior Problems, and Mother-Child Relationship Quality in Autism Spectrum Disorder

This study examined differences in mother-child relationship quality and parent-rated child behavior problems based on child verbal status (i.e., minimally verbal versus verbal) in mothers and their adolescent and adult children with autism spectrum disorder (n = 219 dyads; child M_age = 25.38 years, SD = 10.22). Relationship quality was assessed via parent-reported maternal burden and mother-child closeness, and coded speech samples ascertaining maternal critical and positive remarks regarding the child. Groups did not differ in relationship quality. The verbal group was more likely to display disruptive and socially inappropriate behaviors, but otherwise the groups did not differ in behavior problems. Verbal status moderated the relationship between behavior problems and negative (maternal burden, critical remarks) but not positive (mother-child closeness, positive remarks) aspects of relationship quality.

White matter microstructural and morphometric alterations in autism: implications for intellectual capabilities

Background

Neuroimage literature of autism spectrum disorder (ASD) has a moderate-to-high risk of bias, partially because those combined with intellectual impairment (II) and/or minimally verbal (MV) status are generally ignored. We aimed to provide more comprehensive insights into white matter alterations of ASD, inclusive of individuals with II (ASD-II-Only) or MV expression (ASD-MV).

Methods

Sixty-five participants with ASD (ASD-Whole; 16.6 ± 5.9 years; comprising 34 intellectually able youth, ASD-IA, and 31 intellectually impaired youth, ASD-II, including 24 ASD-II-Only plus 7 ASD-MV) and 38 demographic-matched typically developing controls (TDC; 17.3 ± 5.6 years) were scanned in accelerated diffusion-weighted MRI. Fixel-based analysis was undertaken to investigate the categorical differences in fiber density (FD), fiber cross section (FC), and a combined index (FDC), and brain symptom/cognition associations.

Results

ASD-Whole had reduced FD in the anterior and posterior corpus callosum and left cerebellum Crus I, and smaller FDC in right cerebellum Crus II, compared to TDC. ASD-IA, relative to TDC, had no significant discrepancies, while ASD-II showed almost identical alterations to those from ASD-Whole vs. TDC. ASD-II-Only had greater FD/FDC in the isthmus splenium of callosum than ASD-MV. Autistic severity negatively correlated with FC in right Crus I. Nonverbal full-scale IQ positively correlated with FC/FDC in cerebellum VI. FD/FDC of the right dorsolateral prefrontal cortex showed a diagnosis-by-executive function interaction.

Limitations

We could not preclude the potential effects of age and sex from the ASD cohort, although statistical tests suggested that these factors were not influential. Our results could be confounded by variable psychiatric comorbidities and psychotropic medication uses in our ASD participants recruited from outpatient clinics, which is nevertheless closer to a real-world presentation of ASD. The outcomes related to ASD-MV were considered preliminaries due to the small sample size within this subgroup. Finally, our study design did not include intellectual impairment-only participants without ASD to disentangle the mixture of autistic and intellectual symptoms.

Conclusions

ASD-associated white matter alterations appear driven by individuals with II and potentially further by MV. Results suggest that changes in the corpus callosum and cerebellum are key for psychopathology and cognition associated with ASD. Our work highlights an essential to include understudied subpopulations on the spectrum in research.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13229-022-00499-1.

Large-scale differences in functional organization of left- and right-handed individuals using whole-brain, data-driven analysis of connectivity

Handedness influences differences in lateralization of language areas as well as dominance of motor and somatosensory cortices. However, differences in whole-brain functional connectivity (i.e., functional connectomes) due to handedness have been relatively understudied beyond pre-specified networks of interest. Here, we compared functional connectomes of left- and right-handed individuals at the whole brain level. We explored differences in functional connectivity of previously established regions of interest, and showed differences between primarily left- and primarily right-handed individuals in the motor, somatosensory, and language areas using functional connectivity. We then proceeded to investigate these differences in the whole brain and found that the functional connectivity of left- and right-handed individuals are not specific to networks of interest, but extend across every region of the brain. In particular, we found that connections between and within the cerebellum show distinct patterns of connectivity. To put these effects into context, we show that the effect sizes associated with handedness differences account for a similar amount of individual differences in the connectome as sex differences. Together these results shed light on regions of the brain beyond those traditionally explored that contribute to differences in the functional organization of left- and right-handed individuals and underscore that handedness effects are neurobiologically meaningful in addition to being statistically significant.

Globally elevated excitation-inhibition ratio in children with autism spectrum disorder and below-average intelligence

Background

Altered neuronal excitation–inhibition (E–I) balance is strongly implicated in ASD. However, it is not known whether the direction and degree of changes in the E–I ratio in individuals with ASD correlates with intellectual disability often associated with this developmental disorder. The spectral slope of the aperiodic 1/f activity reflects the E–I balance at the scale of large neuronal populations and may uncover its putative alternations in individuals with ASD with and without intellectual disability.

Methods

Herein, we used magnetoencephalography (MEG) to test whether the 1/f slope would differentiate ASD children with average and below–average (< 85) IQ. MEG was recorded at rest with eyes open/closed in 49 boys with ASD aged 6–15 years with IQ ranging from 54 to 128, and in 49 age-matched typically developing (TD) boys. The cortical source activity was estimated using the beamformer approach and individual brain models. We then extracted the 1/f slope by fitting a linear function to the log–log-scale power spectra in the high-frequency range.

Results

The global 1/f slope averaged over all cortical sources demonstrated high rank-order stability between the two conditions. Consistent with previous research, it was steeper in the eyes-closed than in the eyes-open condition and flattened with age. Regardless of condition, children with ASD and below-average IQ had flatter slopes than either TD or ASD children with average or above-average IQ. These group differences could not be explained by differences in signal-to-noise ratio or periodic (alpha and beta) activity.

Limitations

Further research is needed to find out whether the observed changes in E–I ratios are characteristic of children with below-average IQ of other diagnostic groups.

Conclusions

The atypically flattened spectral slope of aperiodic activity in children with ASD and below-average IQ suggests a shift of the global E–I balance toward hyper-excitation. The spectral slope can provide an accessible noninvasive biomarker of the E–I ratio for making objective judgments about treatment effectiveness in people with ASD and comorbid intellectual disability.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13229-022-00498-2.

Utilising Interview Methodology to Inform the Development of New Clinical Assessment Tools for Anxiety in Autistic Individuals Who Speak Few or no Words

Autistic individuals with intellectual disability who speak few or no words are at high risk of anxiety but are underrepresented in research. This study aimed to describe the presentation of anxiety in this population and discuss implications for the development of assessments. Interviews were conducted with 21 parents/carers of autistic individuals and nine clinicians. Data were analysed using content analysis and interpretative phenomenological analysis. Anxiety behaviours described by parents/carers included increased vocalisation, avoidance and behaviours that challenge. Changes to routine were highlighted as triggering anxiety. Clinicians discussed the importance of identifying an individual's baseline of behaviour, knowing an individual well and ruling out other forms of distress. This study raises considerations for early identification of anxiety and for subsequent support.

Measuring visual electrophysiological responses in individuals with low-functioning autism: a feasibility and pilot study

Background

Although visual abnormalities are considered common in individuals with autism spectrum disorders, the associated electrophysiological markers have remained elusive. One impediment has been that methodological challenges often preclude testing individuals with low-functioning autism (LFA).

Methods

In this feasibility and pilot study, we tested a hybrid visual evoked potential paradigm tailored to individuals with LFA that combines passively presented visual stimuli to elicit scalp-recorded evoked responses with a behavioral paradigm to maintain visual attention. We conducted a pilot study to explore differences in visual evoked response patterns across three groups: individuals with LFA, with high-functioning autism (HFA), and with typical development.

Results

All participants with LFA met criteria for study feasibility by completing the recordings and producing measurable cortical evoked waveform responses. The LFA group had longer (delayed) cortical response latencies on average as compared with the HFA and typical development groups. We also observed group differences in visually induced alpha spectral power: the LFA group showed little to no prestimulus alpha activity in contrast to the HFA and typical development groups that showed increased prestimulus alpha activity. This observation was confirmed by the bootstrapped confidence intervals, suggesting that the absence of prestimulus alpha power may be a potential electrophysiological marker of LFA.

Conclusion

Our results confirm the utility of tailoring visual electrophysiology paradigms to individuals with LFA in order to facilitate inclusion of individuals across the autism spectrum in studies of visual processing.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-021-00960-7.

Rethinking Our Concepts and Assumptions About Autism

Autism is a clinical consensus diagnosis made based on behavioral symptoms of early developmental difficulties in domains of social-communication (SC) and restricted repetitive behaviors (RRB). Many readily assume that alongside being optimal for separating individuals based on SC and RRB behavioral domains, that the label should also be highly useful for explaining differential biology, outcomes, and treatment (BOT) responses. However, we also now take for granted the fact that the autism population is vastly heterogeneous at multiple scales, from genome to phenome. In the face of such multi-scale heterogeneity, here we argue that the concept of autism along with the assumptions that surround it require some rethinking. While we should retain the diagnosis for all the good it can do in real-world circumstances, we also call for the allowance of multiple other possible definitions that are better tailored to be highly useful for other translational end goals, such as explaining differential BOT responses.

A Systematic Review of Passing as Non-autistic in Autism Spectrum Disorder

While long described in anecdotal accounts of the lived experiences of autistic individuals, the phenomenon of behaving in ways that appear inconsistent with the presence of autism (or passing as non-autistic; PAN) has recently seen a dramatic increase in scrutiny in the published scientific literature. Increased research attention has coincided with a proliferation of methods, definitions, measures, and population assumptions associated with PAN. To date, however, no review has sought to systematically identify and synthesize the literature on PAN. This systematic review reflects the state of the PAN literature as of May 2020. Ninety articles were screened, 66 were identified for evaluation, and 46 met inclusion criteria and were reliably coded for study characteristics and participant characteristics. Results reveal that the PAN literature includes a relatively even mix of qualitative, quantitative, and mixed-method studies, and that a variety of terms are used for PAN (with masking and camouflage being the most frequent). Sample sizes varied widely (from one to 832 participants), with 63.06% of participants being categorized as autistic. Nearly all studies reported methods for confirming autism diagnoses, with community and clinical diagnoses being most common. The majority of studies reported participant gender, with slightly more females included than males on average, but fewer than half of all studies compared PAN across genders. Nearly all studies reported participant age, demonstrating a wide range of 2 to 79 years, with a mean age of 23.85. Conversely, only 23.91% of studies provided participant race or ethnicity data. Nearly all studies formally or informally excluded participants with intellectual disability. Finally, measures of internalizing symptoms, which are often thought to be linked to PAN, were reported in only 17.4% of studies. Implications for gaps in understanding of PAN and future directions for the field are discussed.

Looking Back at the Next 40 Years of ASD Neuroscience Research

During the last 40 years, neuroscience has become one of the most central and most productive approaches to investigating autism. In this commentary, we assemble a group of established investigators and trainees to review key advances and anticipated developments in neuroscience research across five modalities most commonly employed in autism research: magnetic resonance imaging, functional near infrared spectroscopy, positron emission tomography, electroencephalography, and transcranial magnetic stimulation. Broadly, neuroscience research has provided important insights into brain systems involved in autism but not yet mechanistic understanding. Methodological advancements are expected to proffer deeper understanding of neural circuitry associated with function and dysfunction during the next 40 years.

Morphometry and functional connectivity of auditory cortex in school-age children with profound language disabilities: Five comparative case studies

Many neurodevelopmental conditions imply absent or severely reduced language capacities at school age. Evidence from functional magnetic resonance imaging is highly limited. We selected a series of five cases scanned with the same fMRI paradigm and the aim of relating individual language profiles onto underlying patterns of functional connectivity (FC) across auditory language cortex: three with neurogenetic syndromes (Coffin-Siris, Landau-Kleffner, and Fragile-X), one with idiopathic intellectual disability, one with autism spectrum disorder (ASD). Compared to both a group with typical development (TD) and a verbal ASD group (total N = 110), they all showed interhemispheric FC below two standard deviations of the TD mean. Children with higher language scores showed higher intrahemispheric FC between Heschl's gyrus and other auditory language regions, as well as an increase of FC during language stimulation compared to rest. An increase of FC in forward vs. reversed speech in the posterior and middle temporal gyri was seen across all cases. The Coffin-Siris case, the most severe, also had the most anomalous FC patterns and showed reduced myelin content, while the Landau-Kleffner case showed reduced cortical thickness. These results suggest potential for neural markers and mechanisms of severe language processing deficits under highly heterogeneous etiological conditions.

Making Research Possible: Barriers and Solutions For Those With ASD and ID

Participation in research can provide direct and indirect benefit to individuals with autism spectrum disorder (ASD), their caregivers, families, and society at large. Unfortunately, individuals with high support needs, including those with intellectual disability, cognitive disability or minimal verbal ability, are often systematically excluded from research on ASD. This limits the ability to generalize discoveries to all people with ASD, and results in a disparity in who benefits from research. This piece outlines the importance and extent of the problem, which is part of a broader lack of inclusivity in ASD research. It also provides examples of studies that have directly addressed issues that arise when conducting inclusive research and makes recommendations for researchers to reduce disparities in research participation.

Update about "minimally verbal" children with autism spectrum disorder

OBJECTIVE

To review clinical and neurobiological features of minimally verbal children with autism spectrum disorder.

DATA SOURCE

We carried out a narrative review using the PubMed database. We considered the following search terms combined through the Boolean operator "AND": "autism spectrum disorder"; "minimally verbal."

DATA SYNTHESIS

To date, there is no shared definition of minimally verbal children with autism spectrum disorder. The heterogeneity in intellectual functioning and in linguistic abilities among these individuals suggests there is no single mechanism underlying their difficulties in learning to speak. However, the reasons why these children do not speak and the biological markers that can identify them are still unknown. Language impairment in these children can lead to several unfavorable consequences, including behavior problems (such as self-aggression, hetero-aggression, and property destruction), poorer daily living and social skills. Psychiatric comorbidities (including attention deficit/hyperactivity disorder, specific phobias, and compulsions) consist in a serious problem related to the lack of verbal language in individuals with autism spectrum disorder. Although in the literature there are very few evidence-based results, several findings suggest that an alternative and augmentative communication intervention, creating an extra-verbal communication channel, may be effective in these individuals.

CONCLUSIONS

The exact definition, clinical characteristics, associated disorders, etiology, and treatment of minimally verbal subjects with autism spectrum disorder must still be further studied and understood.

Autism Voices: A novel method to access first-person perspective of autistic youth

LAY ABSTRACT

The perspective of autistic individuals is often left uncaptured, and as a result they are often excluded from making decisions that impact them. Conventional communication can be challenging for many autistic individuals, especially those who are minimally verbal or who have an associated intellectual disability. Currently, a lack of appropriate methods to capture voices across the spectrum is a barrier. In the present study, we developed the Autism Voices protocol using universal design principles to capture the perspectives and experiences of autistic youth with a range of language or intellectual abilities. This protocol was then used with 33 autistic youth aged 11 to 18 years. A scoring rubric was developed to capture the unconventional communication used by the participants and the mitigation strategies used by interviewers to facilitate the interview. Many components of the protocol were found to effectively facilitate communication between the participant and interviewer, including the use of picture cards to support verbal questions/prompts, the fact that participants could respond with their preferred communication methods (writing, texting, pointing), and the fact that interviews were applied flexibly to adapt to each participant. Unconventional communication and mitigation strategies were mostly observed in interviews with minimally verbal individuals, but a fine-grained analysis showed participants were still communicating something through this unconventional communication. Our protocol could help promote the inclusion of more autistic individuals in research and showed that unconventional modes of communication like echolalia provide an understanding that participants' are invested in conversations and certain topics are more meaningful than others.

Enhanced rationality in autism spectrum disorder

Challenges in social cognition and communication are core characteristics of autism spectrum disorder (ASD), but in some domains, individuals with ASD may display typical abilities and even outperform their neurotypical counterparts. These enhanced abilities are notable in the domains of reasoning, judgment and decision-making, in which individuals with ASD often show 'enhanced rationality' by exhibiting more rational and bias-free decision-making than do neurotypical individuals. We review evidence for enhanced rationality in ASD, how it relates to theoretical frameworks of information processing in ASD, its implications for basic research about human irrationality, and what it may mean for the ASD community.

Inclusion of individuals with low IQ in drug development for autism spectrum disorder

Although individuals with intellectual disability (ID) and/or limited language ability make up a significant proportion of those with autism spectrum disorder (ASD), they are routinely excluded from ASD research. As a result, this vulnerable population is prevented from participating in and deriving full benefit from research. In this commentary, we expand upon points made by McCracken and colleagues (this issue), who describe several opportunities for improvement in drug development for ASD related to the inclusion of individuals with ID and/or limited language ability.

Verbal Ability, Behavior Problems, and Mother-Child Relationship Quality in Autism Spectrum Disorder

This study examined differences in mother-child relationship quality and parent-rated child behavior problems based on child verbal status (i.e., minimally verbal versus verbal) in mothers and their adolescent and adult children with autism spectrum disorder (n = 219 dyads; child M_age = 25.38 years, SD = 10.22). Relationship quality was assessed via parent-reported maternal burden and mother-child closeness, and coded speech samples ascertaining maternal critical and positive remarks regarding the child. Groups did not differ in relationship quality. The verbal group was more likely to display disruptive and socially inappropriate behaviors, but otherwise the groups did not differ in behavior problems. Verbal status moderated the relationship between behavior problems and negative (maternal burden, critical remarks) but not positive (mother-child closeness, positive remarks) aspects of relationship quality.

Rationale of an Advanced Integrative Approach Applied to Autism Spectrum Disorder: Review, Discussion and Proposal

The rationale of an Advanced Integrative Model and an Advanced Integrative Approach is presented. In the context of Allopathic Medicine, this model introduces the evaluation, clinical exploration, diagnosis, and treatment of concomitant medical problems to the diagnosis of Autism Spectrum Disorder. These may be outside or inside the brain. The concepts of static or chronic, dynamic encephalopathy and condition for Autism Spectrum Disorder are defined in this model, which looks at the response to the treatments of concomitant medical problemsto the diagnosis of Autism Spectrum Disorder. (1) Background: Antecedents and rationale of an Advanced Integrative Model and of an Advanced Integrative Approach are presented; (2) Methods: Concomitant medical problems to the diagnosis of Autism Spectrum Disorder and a discussion of the known responses of their treatments are presented; (3) Results: Groups in Autism are defined and explained, related to the responses of the treatments of the concomitant medical problems to ASD and (4) Conclusions: The analysis in the framework of an Advanced Integrative Model of three groups including the concepts of static encephalopathy; chronic, dynamic encephalopathy and condition for Autism Spectrum Disorder explains findings in the field, previously not understood.

Neural Biomarkers Distinguish Severe From Mild Autism Spectrum Disorder Among High-Functioning Individuals

Several previous studies have reported atypicality in resting-state functional connectivity (FC) in autism spectrum disorder (ASD), yet the relatively small effect sizes prevent us from using these characteristics for diagnostic purposes. Here, canonical correlation analysis (CCA) and hierarchical clustering were used to partition the high-functioning ASD group (i.e., the ASD discovery group) into subgroups. A support vector machine (SVM) model was trained through the 10-fold strategy to predict Autism Diagnostic Observation Schedule (ADOS) scores within the ASD discovery group (r = 0.30, P < 0.001, n = 260), which was further validated in an independent sample (i.e., the ASD validation group) (r = 0.35, P = 0.031, n = 29). The neuroimage-based partition derived two subgroups representing severe versus mild autistic patients. We identified FCs that show graded changes in strength from ASD-severe, through ASD-mild, to controls, while the same pattern cannot be observed in partitions based on ADOS score. We also identified FCs that are specific for ASD-mild, similar to a partition based on ADOS score. The current study provided multiple pieces of evidence with replication to show that resting-state functional magnetic resonance imaging (rsfMRI) FCs could serve as neural biomarkers in partitioning high-functioning autistic individuals based on their symptom severity and showing advantages over traditional partition based on ADOS score. Our results also indicate a compensatory role for a frontocortical network in patients with mild ASD, indicating potential targets for future clinical treatments.

The relationship between sensory reactivity differences and mental health symptoms in preschool-age autistic children

There is growing evidence for an association between sensory reactivity and mental health in autism. This study set out to explore the relationship between sensory reactivity and mental health in preschool-aged autistic children. In total 54 preschool-aged children with an Autism Spectrum Condition took part. Sensory and mental health symptoms were obtained from the Sensory Processing Scale Inventory, Sensory Assessment of Neurodevelopmental Differences and the Behavioral Assessment System for Children-3. Correlational analyses showed a relationship between sensory reactivity and mental health symptoms in autistic preschool-aged children. Results also indicate divergence in sensory-mental health profiles between autistic preschool-aged children who are verbal and those who use few to no words. For the first time this study has revealed a relationship between sensory hyper-reactivity, as well as sensory seeking, and mental health symptoms outside of anxiety in autism. Of note, this relationship between sensory hyper-reactivity and internalizing symptoms appears to be driven by those with few to no words. This has implications for both research and clinical interventions, in particular for our understanding of the factors underlying mental health symptoms in different autistic phenotypes, as well as the possible role of functional communication in mitigating the development of mental health symptoms. LAY SUMMARY: The present study found that in autistic preschoolers, externalizing mental health symptoms, such as hyperactivity, are related to sensory seeking (seeking out or being fascinated with sensory stimuli), and internalizing mental health symptoms, such as depression, are related to sensory hyper-reactivity (sensitivity to sensory stimuli). Our results also show that whilst the relationships between externalizing symptoms and sensory seeking is seen across participants, the relationship between internalizing symptoms and sensory hyper-reactivity was only seen in autistic preschoolers who used few to no words. This has important implications for the assessment of sensory differences as part of more rigorous mental health assessments, especially in autistic people who use few to no words.

[11C]PBR28 MR-PET imaging reveals lower regional brain expression of translocator protein (TSPO) in young adult males with autism spectrum disorder

Mechanisms of neuroimmune and mitochondrial dysfunction have been repeatedly implicated in autism spectrum disorder (ASD). To examine these mechanisms in ASD individuals, we measured the in vivo expression of the 18 kDa translocator protein (TSPO), an activated glial marker expressed on mitochondrial membranes. Participants underwent scanning on a simultaneous magnetic resonance-positron emission tomography (MR-PET) scanner with the second-generation TSPO radiotracer [11C]PBR28. By comparing TSPO in 15 young adult males with ASD with 18 age- and sex-matched controls, we showed that individuals with ASD exhibited lower regional TSPO expression in several brain regions, including the bilateral insular cortex, bilateral precuneus/posterior cingulate cortex, and bilateral temporal, angular, and supramarginal gyri, which have previously been implicated in autism in functional MR imaging studies. No brain region exhibited higher regional TSPO expression in the ASD group compared with the control group. A subset of participants underwent a second MR-PET scan after a median interscan interval of 3.6 months, and we determined that TSPO expression over this period of time was stable and replicable. Furthermore, voxelwise analysis confirmed lower regional TSPO expression in ASD at this later time point. Lower TSPO expression in ASD could reflect abnormalities in neuroimmune processes or mitochondrial dysfunction.

The Feasibility of Magnetic Resonance Imaging in a Non-Selective Comprehensive Clinical Trial in Pediatric Autism Spectrum Disorder

There is an increasing interest in using magnetic resonance imaging (MRI) as a tool for precision medicine in autism spectrum disorder (ASD). This study investigated the feasibility of MRI scanning in a large comprehensive, inclusive and test heavy clinical trial for children (aged 3-12 years) with ASD, without functioning constraints for participation. Of the 71 participants enrolled who consented to the MRI, 24 participants (38%) successfully completed an MRI scan at baseline along with other assessments. This scanning followed a familiarization procedure at two preceding visits. At post-treatment, 21 participants successfully completed the MRI scan. This study highlights the challenge of completing MRI assessments in ASD populations when conducted as one of a number of tests in a clinical trial.

Overcoming hurdles to intervention studies with autistic children with profound communication difficulties and their families

Autistic children and adults who are non-verbal/minimally verbal or have an intellectual disability have often been excluded from Autism Spectrum Disorder research. Historical, practical and theoretical reasons for this exclusion continue to deter some researchers from work with this underserved population. We discuss why these reasons are neither convincing nor ethical, and provide strategies for dealing with practical issues. As part of a randomised controlled trial of an intervention for children with profound autism, we reflected as a multi-disciplinary team on what we had learnt from these children, their families and each other. We provide 10 strategies to overcome what appeared initially to be barriers to collecting data with this population. These hurdles and our solutions are organised by theme: interacting physically with children, how to play and test, navigating difficult behaviours, selecting suitable outcome measures, relating with parents, managing siblings, involving stakeholders, timing interactions, the clinician’s role in managing expectations, and recruitment. The aim of this article is to provide researchers with the tools to feel motivated to conduct research with children with profound autism and their families, a difficult but worthwhile endeavour. Many of these lessons also apply to conducting research with non-autistic children with intellectual disabilities.

Tactile cortical responses and association with tactile reactivity in young children on the autism spectrum

Background

Unusual behavioral reactions to sensory stimuli are frequently reported in individuals on the autism spectrum (AS). Despite the early emergence of sensory features (< age 3) and their potential impact on development and quality of life, little is known about the neural mechanisms underlying sensory reactivity in early childhood autism.

Methods

Here, we used electroencephalography (EEG) to investigate tactile cortical processing in young children aged 3–6 years with autism and in neurotypical (NT) children. Scalp EEG was recorded from 33 children with autism, including those with low cognitive and/or verbal abilities, and 45 age- and sex-matched NT children during passive tactile fingertip stimulation. We compared properties of early and later somatosensory-evoked potentials (SEPs) and their adaptation with repetitive stimulation between autistic and NT children and assessed whether these neural measures are linked to “real-world” parent-reported tactile reactivity.

Results

As expected, we found elevated tactile reactivity in children on the autism spectrum. Our findings indicated no differences in amplitude or latency of early and mid-latency somatosensory-evoked potentials (P50, N80, P100), nor adaptation between autistic and NT children. However, latency of later processing of tactile information (N140) was shorter in young children with autism compared to NT children, suggesting faster processing speed in young autistic children. Further, correlational analyses and exploratory analyses using tactile reactivity as a grouping variable found that enhanced early neural responses were associated with greater tactile reactivity in autism.

Limitations

The relatively small sample size and the inclusion of a broad range of autistic children (e.g., with low cognitive and/or verbal abilities) may have limited our power to detect subtle group differences and associations. Hence, replications are needed to verify these results.

Conclusions

Our findings suggest that electrophysiological somatosensory cortex processing measures may be indices of “real-world” tactile reactivity in early childhood autism. Together, these findings advance our understanding of the neurophysiological mechanisms underlying tactile reactivity in early childhood autism and, in the clinical context, may have therapeutic implications.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13229-021-00435-9.

Neural Correlates of Interpersonal Space Permeability and Flexibility in Autism Spectrum Disorder

Previous research indicates that the size of interpersonal space at which the other is perceived as intrusive (permeability) and the ability to adapt interpersonal distance based on contextual factors (flexibility) are altered in Autism Spectrum Disorder (ASD). However, the neurophysiological basis of these alterations remains poorly understood. To fill this gap, we used fMRI and assessed interpersonal space preferences of individuals with ASD before and after engaging in cooperative and non-cooperative social interactions. Compared to matched controls, ASDs showed lower comfort in response to an approaching confederate, indicating preference for larger interpersonal space in autism (altered permeability). This preference was accompanied by reduced activity in bilateral dorsal intraparietal sulcus (dIPS) and left fusiform face area (FFA), regions previously shown to be involved in interpersonal space regulation. Furthermore, we observed differences in effective connectivity among dIPS, FFA, and amygdala in ASDs compared to controls, depending on the level of experienced comfort. No differences between groups were observed in interpersonal space regulation after an experienced social interaction (flexibility). Taken together, the present findings suggest that a dysregulation of the activity and connectivity of brain areas involved in interpersonal space processing may contribute to avoidance of physical proximity and social impairments in ASD.

IQ and Internalising Symptoms in Adolescents with ASD

Intelligence quotient (IQ), has been found to relate to the presence of internalising symptoms in autism spectrum disorder (ASD). This meta-analysis sought to clarify the direction of the relationship between IQ and two prevalent internalising symptoms, anxiety and depression, in adolescents with ASD. Secondly, this study aimed to highlight methodological factors contributing to inconsistent findings in existing research. Self-reported anxiety was found to be significantly higher in youth with a lower IQ, while depression was positively associated with IQ. Consequently, parents, schools and clinicians should be cautious of underestimating anxiety in youth with a lower IQ. However, care should also be taken to ensure adolescents with ASD without intellectual disabilities are not overlooked with regards to social and emotional support.

Definitions of Nonverbal and Minimally Verbal in Research for Autism: A Systematic Review of the Literature

This systematic review examined definitions of "nonverbal" or "minimally verbal" and assessment measures used to evaluate communication in intervention studies focusing on improving expressive verbal communication in children with autism spectrum disorder (ASD). We reviewed sample size, number of participants, participant age, and male/female representation. Our analysis yielded relatively few studies with non/minimally verbal children with ASD focusing on verbal expressive communication. Further, we found large inconsistencies in measures used, definitions of "nonverbal" and "minimally verbal", and ages targeted. Guidelines are suggested to create a more uniform assessment protocol with systematic descriptions of early communication learners as a foundational step for understanding the heterogeneity in this group and replicating research findings for this subgroup of children with ASD.

Visuo-attentional correlates of Autism Spectrum Disorder (ASD) in children with Down syndrome: A comparative study with children with idiopathic ASD

BACKGROUND

Children with Down syndrome (DS) are at increased likelihood of Autism Spectrum Disorder (ASD) relative to the general population. To better understand the nature of this comorbidity, we examined the visuo-attentional processes associated with autistic trait expression in children with DS, focusing specifically on attentional disengagement and visual search performance.

METHOD

We collected eye-tracking data from children with DS (n = 15) and children with idiopathic ASD (iASD, n = 16) matched according to chronological age. Seven children with DS had a formal clinical diagnosis of ASD (DS+ASD).

RESULTS

In children with iASD, but not DS, higher autistic trait levels were associated with decreased temporal facilitation on a gap-overlap task, implying increased visuospatial orienting efficiency. In all cases, higher autistic trait levels were associated with improved visual search performance according to decreased target detection latency. On a visual search task, children with DS+ASD outperformed their peers with DS-ASD, mirroring the phenotypic advantage associated with iASD. We found no evidence of a relationship between attentional disengagement and visual search performance, providing preliminary evidence of a differentiation in terms of underlying visuo-attentional mechanism.

CONCLUSION

We illustrate the value of progressing beyond insensitive behavioural measures of phenotypic description to examine, in a more fine-grained way, the attentional features associated with ASD comorbidity in children with DS.

Association of self-regulation with white matter correlates in boys with and without autism spectrum disorder

Previous studies demonstrated distinct neural correlates underpinning impaired self-regulation (dysregulation) between individuals with autism spectrum disorder (ASD) and typically developing controls (TDC). However, the impacts of dysregulation on white matter (WM) microstructural property in ASD and TDC remain unclear. Diffusion spectrum imaging was acquired in 59 ASD and 62 TDC boys. We investigated the relationship between participants’ dysregulation levels and microstructural property of 76 WM tracts in a multivariate analysis (canonical correlation analysis), across diagnostic groups. A single mode of brain-behavior co-variation was identified: participants were spread along a single axis linking diagnosis, dysregulation, diagnosis-by-dysregulation interaction, and intelligence to a specific WM property pattern. This mode corresponds to diagnosis-distinct correlates underpinning dysregulation, which showed higher generalized fractional anisotropy (GFA) associated with less dysregulation in ASD but greater dysregulation in TDC, in the tracts connecting limbic and emotion regulation systems. Moreover, higher GFA of the tracts implicated in memory, attention, sensorimotor processing, and perception associated with less dysregulation in TDC but worse dysregulation in ASD. No shared WM correlates of dysregulation between ASD and TDC were identified. Corresponding to previous studies, we demonstrated that ASD and TDC have broad distinct white matter microstructural property underpinning self-regulation.

Adjusting for allometric scaling in ABIDE I challenges subcortical volume differences in autism spectrum disorder

Inconsistencies across studies investigating subcortical correlates of autism spectrum disorder (ASD) may stem from small sample size, sample heterogeneity, and omitting or linearly adjusting for total brain volume (TBV). To properly adjust for TBV, brain allometry—the nonlinear scaling relationship between regional volumes and TBV—was considered when examining subcortical volumetric differences between typically developing (TD) and ASD individuals. Autism Brain Imaging Data Exchange I (ABIDE I; N = 654) data was analyzed with two methodological approaches: univariate linear mixed effects models and multivariate multiple group confirmatory factor analyses. Analyses were conducted on the entire sample and in subsamples based on age, sex, and full scale intelligence quotient (FSIQ). A similar ABIDE I study was replicated and the impact of different TBV adjustments on neuroanatomical group differences was investigated. No robust subcortical allometric or volumetric group differences were observed in the entire sample across methods. Exploratory analyses suggested that allometric scaling and volume group differences may exist in certain subgroups defined by age, sex, and/or FSIQ. The type of TBV adjustment influenced some reported volumetric and scaling group differences. This study supports the absence of robust volumetric differences between ASD and TD individuals in the investigated volumes when adjusting for brain allometry, expands the literature by finding no group difference in allometric scaling, and further suggests that differing TBV adjustments contribute to the variability of reported neuroanatomical differences in ASD.

Social endophenotypes in autism spectrum disorder: A scoping review

Endophenotypes are measurable markers of genetic vulnerability to current or future disorder. Autism spectrum disorder (ASD) is well-suited to be examined within an endophenotype framework given past and current emphases on the broader autism phenotype and early detection. We conducted a scoping review to identify potential socially-related endophenotypes of ASD. We focused on paradigms related to sociality (e.g., theory of mind (TOM), social attention), which comprise most of this literature. We integrated findings from traditional behavioral paradigms with brain-based measures (e.g., electroencephalography, functional magnetic resonance imaging). Broadly, infant research regarding social attention and responsivity (Research Domain Criteria (RDoC) domain of affiliation) and attention to faces and voices (social communication) finds consistent abnormality in vulnerable infant siblings. Several additional paradigms that have shown differences in vulnerable infants and young children include animacy perception tasks (perception and understanding of others), measures of recognition and response to familiar faces (attachment), and joint attention and false-belief tasks (understanding mental states). Research areas such as alexithymia (the perception and understanding of self), empathic responding, and vocal prosody may hold interest; however, challenges in measurement across populations and age ranges is a limiting factor. Future work should address sex differences and age dependencies, specificity to ASD, and heterogeneous genetic pathways to disorder within samples individuals with ASD and relatives.

The Adapted ADOS: A New Module Set for the Assessment of Minimally Verbal Adolescents and Adults

Few measures are appropriate to assess autism symptoms in minimally verbal adolescents and adults. The Autism Diagnostic Observation Schedule, 2nd Edition (ADOS-2, Lord et al., in Autism diagnostic observation schedule-2nd edition (ADOS-2). Western Psychological Services, Los Angeles, 2012) Modules 1 and 2 were designed and validated with children whose spoken language ranges from few- to- no words to phrase speech. This study describes the development and initial validation of the Adapted-ADOS (A-ADOS), which includes tasks, materials and behavioral codes modified to be suitable for assessing older minimally verbal individuals. A-ADOS algorithms exhibit comparable sensitivity and improved specificity relative to ADOS-2 Modules 1 and 2. Although further validation is needed, the A-ADOS will facilitate research to further understanding of minimally verbal adults and symptom trajectories across the lifespan.

Parent Education in Studies With Nonverbal and Minimally Verbal Participants With Autism Spectrum Disorder: A Systematic Review

Purpose The purpose of this systematic review was to identify parent education procedures implemented in intervention studies focused on expressive verbal communication for nonverbal (NV) or minimally verbal (MV) children with autism spectrum disorder (ASD). Parent education has been shown to be an essential component in the habilitation of individuals with ASD. Parents of individuals with ASD who are NV or MV may particularly benefit from parent education in order to provide opportunities for communication and to support their children across the life span. Method ProQuest databases were searched between the years of 1960 and 2018 to identify articles that targeted verbal communication in MV and NV individuals with ASD. A total of 1,231 were evaluated to assess whether parent education was implemented. We found 36 studies that included a parent education component. These were reviewed with regard to (a) the number of participants and participants' ages, (b) the parent education program provided, (c) the format of the parent education, (d) the duration of the parent education, (e) the measurement of parent education, and (f) the parent fidelity of implementation scores. Results The results of this analysis showed that very few studies have included a parent education component, descriptions of the parent education programs are unclear in most studies, and few studies have scored the parents' implementation of the intervention. Conclusions Currently, there is great variability in parent education programs in regard to participant age, hours provided, fidelity of implementation, format of parent education, and type of treatment used. Suggestions are made to provide both a more comprehensive description and consistent measurement of parent education programs.

Sensorimotor Research Utilising Immersive Virtual Reality: A Pilot Study with Children and Adults with Autism Spectrum Disorders

When learning and interacting with the world, people with Autism Spectrum Disorders (ASD) show compromised use of vision and enhanced reliance on body-based information. As this atypical profile is associated with motor and social difficulties, interventions could aim to reduce the potentially isolating reliance on the body and foster the use of visual information. To this end, head-mounted displays (HMDs) have unique features that enable the design of Immersive Virtual Realities (IVR) for manipulating and training sensorimotor processing. The present study assesses feasibility and offers some early insights from a new paradigm for exploring how children and adults with ASD interact with Reality and IVR when vision and proprioception are manipulated. Seven participants (five adults, two children) performed a self-turn task in two environments (Reality and IVR) for each of three sensory conditions (Only Proprioception, Only Vision, Vision + Proprioception) in a purpose-designed testing room and an HMD-simulated environment. The pilot indicates good feasibility of the paradigm. Preliminary data visualisation suggests the importance of considering inter-individual variability. The participants in this study who performed worse with Only Vision and better with Only Proprioception seemed to benefit from the use of IVR. Those who performed better with Only Vision and worse with Only Proprioception seemed to benefit from Reality. Therefore, we invite researchers and clinicians to consider that IVR may facilitate or impair individuals depending on their profiles.

Effects of oxytocin administration on salivary sex hormone levels in autistic and neurotypical women

Background

Oxytocin administration, which may be of therapeutic value for individuals with social difficulties, is likely to affect endogenous levels of other socially relevant hormones. However, to date, the effects of oxytocin administration on endogenous hormones have only been examined in neurotypical individuals. The need to consider multi-hormone interactions is particularly warranted in oxytocin trials for autism due to evidence of irregularities in both oxytocin and sex steroid systems.

Methods

In this double-blind cross-over study, saliva samples were collected from 16 autistic and 29 neurotypical women before and after intranasal administration of 24 IU oxytocin or placebo. Oestradiol, testosterone, and oxytocin levels were quantified in saliva samples. Participants also completed the Autism-Spectrum Quotient (AQ) and Empathy Quotient (EQ) questionnaires.

Results

Distinct patterns of change in testosterone and oestradiol levels pre- to-post-administration were observed in autistic relative to neurotypical women (ANCOVA, p < 0.05 main effect of Group), controlling for sample collection time. The mean percent change oestradiol was + 8.8% for the autism group and − 13.0% for the neurotypical group (t = 1.81, p = 0.08), while the mean percent change testosterone was + 1.1% in the autism group and − 12.6% in the neurotypical group (t = 1.26, p = 0.22). In the oxytocin condition, the mean percent change oestradiol was + 12.6% in the autism group and − 6.9% in the neurotypical group (t = 1.78, p = 0.08), while the mean percent change testosterone was + 14.4% in the autism group and − 15.2% in the neurotypical group (t = 3.00, p = 0.006). Robust regression confirmed that group differences in percent change hormone levels were not driven by a small number of influential individuals. Baseline hormone levels did not differ between groups when considered individually. However, baseline testosterone relative to oestradiol (T:E2 ratio) was higher in autistic women (p = 0.023, Cohen’s d = 0.63), and this ratio correlated positively and negatively with AQ and EQ scores, respectively, in the combined sample.

Limitations

Further studies with larger and more diverse autistic sample are warranted to confirm these effects.

Conclusions

This study provides the first evidence that oxytocin influences endogenous testosterone levels in autistic individuals, with autistic women showing increases similar to previous reports of neurotypical men. These findings highlight the need to consider sex steroid hormones as a variable in future oxytocin trials.

Annual Research Review: Looking back to look forward - changes in the concept of autism and implications for future research

The concept of autism is a significant contribution from child psychiatry that has entered wider culture and public consciousness, and has evolved significantly over the last four decades. Taking a rather personal retrospective, reflecting on our own time in autism research, this review explores changes in the concept of autism and the implications of these for future research. We focus on seven major changes in how autism is thought of, operationalised, and recognised: (1) from a narrow definition to wide diagnostic criteria; (2) from a rare to a relatively common condition, although probably still under-recognised in women; (3) from something affecting children, to a lifelong condition; (4) from something discreet and distinct, to a dimensional view; (5) from one thing to many 'autisms', and a compound or 'fractionable' condition; (6) from a focus on 'pure' autism, to recognition that complexity and comorbidity is the norm; and finally, (7) from conceptualising autism purely as a 'developmental disorder', to recognising a neurodiversity perspective, operationalised in participatory research models. We conclude with some challenges for the field and suggestions for areas currently neglected in autism research.

Developing the Multidimensional Visual Scale Assessing Affect, Anxiety, Pride, and Energy Through a Research Partnership with Autistic Scholars

Autism research studies have traditionally failed to represent the full diversity of the autism spectrum due to the lack of measures available for use with participants who prefer to express themselves visually. A multidimensional measure of emotions, which can include both picture- and text-based prompts, may improve accessibility of emotion rating measures and broaden participation in research and educational evaluations to include those who communicate in diverse ways. Picture-based measures designed to assess participants' emotions may be useful for research concerning autistic identity and service evaluation, two areas where representation of diverse perspectives is needed. Our participatory group of autistic and nonautistic researchers developed a Multidimensional Visual Scale Assessing Affect, Anxiety, Pride, and Energy (AAPE) by adapting and expanding upon an existing emotion rating scale. When testing the AAPE with autistic college students (n = 72), their open-ended responses indicated that the AAPE's dimensions of affect (97.2% correct), anxiety (79.2% correct), and energy (84.7% correct) were well comprehended without text-based labels with potential for improvement in how pride (52.8% correct) was represented. When provided with the labels that each dimension was intended to represent, participants generally agreed that each emotional dimension was well represented. When tested in an informal educational summer camp with autistic children and adolescents (n = 50), the AAPE was well received and revealed insights about the students' emotional responses to different instructional strategies that can guide curricular improvements. The AAPE has utility as a tool to help diverse autistic individuals self-advocate and improve research and services.

Lay summary

Why was this study done?: There are very few tools that autistic people can use to share how they feel. We wanted to develop a tool to help autistic people express their emotions using pictures. Pictures can help autistic people share how they feel.What was the purpose of this study?: We wanted to make an easy-to-understand tool that autistic people can use to share how they feel.What did the researchers do?: Our research group is participatory, meaning that autistic and nonautistic researchers worked together to make our tool. An autistic artist drew the tool. We called it the AAPE, which stands for the emotions it assesses: Affect, Anxiety, Pride, and Energy. We worked together to see how well the AAPE worked. We used a survey to see if autistic high school and college students understood our first try at the AAPE and we learned how to make the AAPE better from these students. We worked together to make the AAPE better. Then, we did another survey with autistic college students to see if our second try at the AAPE worked better. Then, we asked autistic kids and teenagers to use the AAPE to share how they felt about different ways of teaching.What were the results of the study?: In our final test, we asked 72 autistic college students to tell us what emotions they thought the AAPE was showing. College students thought that affect (97.2%), anxiety (79.2%), and energy (84.7%) showed the emotions we aimed to show with room for improvement in how pride (52.8%) was shown. After we told participants which emotion each scale was showing, they agreed that affect (average score 4.28 of 5) and anxiety (4.29 of 5) showed the emotions best, followed by energy (4.08 of 5) and pride (3.5 of 5) on a scale from 1 to 5 (strongly agree).Students preferred using the AAPE compared with text-based surveys we used in the past. Results showed that the AAPE does a good job at measuring emotions. Edits may still be needed to better show "pride." Work is needed with nonspeaking people to make sure our measure works well for people who communicate in different ways.What are potential weaknesses in the study?: The autistic adolescents and adults we have tested the AAPE with so far have not been very diverse. We did not include participants who communicate without speaking in these first tests of the AAPE. We plan to use the AAPE with more diverse groups in future studies.How will these findings help autistic adults now or in the future?: In a future study, we will use the AAPE to rate pictures that show experiences of being autistic, like feeling outside a social group, having sensory difficulties, and making patterns. We would like to do this because some studies talk about negative experiences of autism, like feeling the need to hide autistic traits, but other studies describe strengths of autism, like strong memories and advanced knowledge in particular subjects. However, these studies do not talk about the emotions that come with these experiences and if these experiences are shared with autistic people who do not use speech to communicate. The AAPE is a tool that might help us understand how diverse autistic people feel about autism.

Atypical Pattern of Frontal EEG Asymmetry for Direct Gaze in Young Children with Autism Spectrum Disorder

This study examined approach-motivation related brain activity (frontal electroencephalogram [EEG] asymmetry) in response to direct and averted gaze in 3- to 6-year-old typically developing (TD) children, children with autism spectrum disorder (ASD), and those with intellectual disability (ID). We found that, in TD children, direct gaze elicited greater approach-related frontal EEG activity than did downcast gaze. This pattern of activity was in contrast to that observed in children with ASD, who showed greater approach-related activity in response to downcast gaze than to direct gaze. ID children did not differ in their responses to different gaze conditions. These findings indicate that another person’s direct gaze does not elicit approach-motivation related brain activity in young children with ASD.