Autism Samples Research Articles

A Systematic Review of Gender Dysphoria Measures in Autistic Samples

This systematic review investigated how studies have measured gender dysphoria (GD) in autistic samples and the impact of using different measures on study results. The literature search identified 339 relevant papers, with 12 of them meeting the inclusion criteria. Results showed that seven different measures of GD characteristics have been used with autistic samples and that the studies consistently reported a greater number of GD characteristics and a greater severity of GD in autistic compared to non-autistic samples. Methodological common practices were found in recruiting participants from clinical settings rather than the general population, having more autistic males than females in the samples, for studies being conducted in Europe, North America, and Oceania, and using single-item measures of GD for samples of autistic children. Issues were identified with study designs and measures of GD, suggesting a need for a more standardized multi-item self-report measure of GD for use in clinical and non-clinical samples across different ages and cultures.

Measuring and validating autistic burnout.

Researchers have begun to explore the characteristics and risk factors for autistic burnout, but assessment tools are lacking. Our study comprehensively examined and compared the psychometric properties of the unpublished 27-item AASPIRE Autistic Burnout Measure (ABM), and personal and work scales of the Copenhagen Burnout Inventory (CBI) to evaluate their efficacy as screening measures for autistic burnout, with a group of 238 autistic adults. Exploratory factor analyses (EFA) revealed a 4-factor structure for the ABM and a 2-factor structure for the CBI personal scale (CBI-P). Factorial validity and dimensionality were examined with four exploratory models which indicated a unidimensional structure for the ABM with an overarching 'Autistic Burnout' construct, and multidimensional CBI-P structure comprising two subscales and overarching 'Personal Burnout' construct. Other reliability and validity indicators included Spearman correlations, analysis of variance, receiver operating characteristics, sensitivity, specificity, and intra-class correlations (ICC). The ABM and CBI-P were strongly correlated with depression, anxiety, stress, and fatigue. Unexpectedly, correlations between the burnout measures and camouflaging, and wellbeing measures were moderate. Potential overlap between burnout and depression and fatigue was examined through EFA, which supported convergent validity of the ABM and depression measure, while correlations and ICC analyses revealed mixed results. We concluded that the ABM and the CBI-P Emotional Exhaustion subscale were valid preliminary screening tools for autistic burnout. Testing with larger and more diverse autistic samples is required to further examine the psychometric properties of the ABM, and to understand the relationships between autistic burnout and depression, and masking.

Gender, assigned sex at birth, and gender diversity: Windows into diagnostic timing disparities in autism.

Later autism diagnosis is associated with risk for mental health problems. Understanding factors related to later autism diagnosis may help reduce mental health risks for autistic people. One characteristic associated with later autism diagnosis is female sex. However, studies often do not distinguish sex assigned at birth and gender identity. Gender diversity may be more common in autistic relative to neurotypical people, and autism is more common in gender-diverse populations. We studied age at autism diagnosis by sex assigned at birth, gender identity, and gender diversity (gender-diverse vs cisgender) status, separately. We studied three separate autistic samples, each of which differed in how they were diagnosed and how they were recruited. The samples included 193 persons (8.0-18.0 years) from a research-recruited academic medical center sample; 1,550 people (1.3-25.4 years) from a clinic-based sample; and 244 people (18.2-30.0 years) from a community-enriched sample. We found significant differences in the clinic-based and community-enriched samples. People assigned female sex at birth were diagnosed with autism significantly later than people assigned male at birth. People of female gender were diagnosed significantly later than people of male gender. Gender-diverse people were diagnosed significantly later than cisgender people. Sex assigned at birth, gender identity, and gender diversity may each show unique relationships with age of autism diagnosis. Differences in how autistic people are diagnosed and recruited are important to consider in studies that examine sex assigned at birth or gender identity. More research into autism diagnosis in adulthood is needed.

Autism and Hierarchical Models of Intelligence.

The Wechsler Intelligence Scale for Children (WISC) employs a hierarchical model of general intelligence in which index scores separate out different clinically-relevant aspects of intelligence; the test is designed such that index scores are statistically independent from one another within the normative sample. Whether or not the existing index scores meet the desired psychometric property of being statistically independent within autistic samples is unknown. We conducted a factor analysis on WISC fifth edition (WISC-V) (N = 83) and WISC fourth edition (WISC-IV) (N = 131) subtest data in children with autism. We compared the data-driven exploratory factor analysis with the manual-derived index scores, including in a typically developing (TD) WISC-IV cohort (N = 209). The WISC-IV TD cohort showed the expected 1:1 relationship between empirically derived factors and manual-derived index scores. We observed less unique correlations between our data-driven factors and manualized IQ index scores in both ASD samples (WISC-IV and WISC-V). In particular, in both WISC-IV and -V, working memory (WM) influenced index scores in autistic individuals that do not load on WM in the normative sample. WISC index scores do not show the desired statistical independence within autistic samples, as judged against an empirically-derived exploratory factor analysis. In particular, within the currently used WISC-V version, WM influences multiple index scores.

Exome-wide analysis identify multiple variations in olfactory receptor genes (OR12D2 and OR5V1) associated with autism spectrum disorder in Saudi females.

Autism Spectrum Disorder (ASD) is a multifactorial, neurodevelopmental disorder, characterized by deficits in communication, restricted and repetitive behaviors. ASD is highly heritable in Saudi Arabia; indecencies of affected individuals are increasing. To identify the most significant genes and SNPs associated with the increased risk of ASD in Saudi females to give an insight for early diagnosis. Pilot case-control study mostly emphasized on the significant SNPs and haplotypes contributing to Saudi females with ASD patients (n = 22) compared to controls (n = 51) without ASD. With the use of allelic association analysis tools, 243,345 SNPs were studied systematically and classified according to their significant association. The significant SNPs and their genes were selected for further investigation for mapping of ASD candidate causal variants and functional impact. In females, five risk SNPs at p ≤ 2.32 × 10-05 was identified in association with autism. The most significant exonic variants at chromosome 6p22.1 with olfactory receptor genes (OR12D2 and OR5V1) clustered with high linkage disequilibrium through haplotyping analysis. Comparison between highly associated genes (56 genes) of male and female autistic patients with female autistic samples revealed that 39 genes are unique biomarkers for Saudi females with ASD. Multiple variations in olfactory receptor genes (OR5V1 and OR12D2) and single variations on SPHK1, PLCL2, AKAP9 and LOC107984893 genes are contributing to ASD in females of Arab origin. Accumulation of these multiple predisposed coding SNPs can increase the possibility of developing ASD in Saudi females.

The Inter-Relationship of Emotion Regulation, Self-Compassion, and Mental Health in Autistic Adults.

Emotion regulation is one of the key factors that influence mental health outcomes in autistic and nonautistic populations. Recent research has also identified self-compassion as a negative correlate of depression and positive correlate of psychological well-being in autistic adults. Empirical evidence from the general population supports the notion that being kind and compassionate toward oneself during stressful and difficult moments can help with one's ability to regulate negative emotions, which then has flow-on effects on mental health outcomes. However, the inter-relationship between self-compassion, emotion regulation, and mental health has not been examined in autistic samples. Therefore, the aim of this study was to determine if emotion regulation mediates the relationship between self-compassion and anxiety or depression in a sample of autistic adults. Participants were 153 adults (meanage = 35.70, standard deviationage = 12.62) who had either self-reported a clinical diagnosis of autism spectrum disorder or self-identified as autistic. They completed an online survey capturing self-compassion, emotion regulation, anxiety, and depression. We hypothesized that emotion regulation would mediate the relationship between self-compassion and anxiety or depression, and self-compassion would not mediate the relationship between emotion regulation and anxiety or depression. As predicted, only emotion regulation mediated the relationship between self-compassion and mental health outcomes. Self-compassion did not mediate the relationship between emotion regulation and mental health outcomes. This study provides preliminary evidence for the role that self-compassion plays in improving emotion regulation and mental health in autistic adults. If this mechanism of emotion regulation mediating the relationship between self-compassion and mental health is consistently found in future studies, then it would be helpful for future research to examine the clinical benefits of including a self-compassion component in emotion regulation interventions to improve mental health outcomes of autistic adults.

Biomarker prediction in autism spectrum disorder using a network-based approach

BackgroundAutism is a neurodevelopmental disorder that is usually diagnosed in early childhood. Timely diagnosis and early initiation of treatments such as behavioral therapy are important in autistic people. Discovering critical genes and regulators in this disorder can lead to early diagnosis. Since the contribution of miRNAs along their targets can lead us to a better understanding of autism, we propose a framework containing two steps for gene and miRNA discovery.MethodsThe first step, called the FA_gene algorithm, finds a small set of genes involved in autism. This algorithm uses the WGCNA package to construct a co-expression network for control samples and seek modules of genes that are not reproducible in the corresponding co-expression network for autistic samples. Then, the protein–protein interaction network is constructed for genes in the non-reproducible modules and a small set of genes that may have potential roles in autism is selected based on this network. The second step, named the DMN_miRNA algorithm, detects the minimum number of miRNAs related to autism. To do this, DMN_miRNA defines an extended Set Cover algorithm over the mRNA–miRNA network, consisting of the selected genes and corresponding miRNA regulators.ResultsIn the first step of the framework, the FA_gene algorithm finds a set of important genes; TP53, TNF, MAPK3, ACTB, TLR7, LCK, RAC2, EEF2, CAT, ZAP70, CD19, RPLP0, CDKN1A, CCL2, CDK4, CCL5, CTSD, CD4, RACK1, CD74; using co-expression and protein–protein interaction networks. In the second step, the DMN_miRNA algorithm extracts critical miRNAs, hsa-mir-155-5p, hsa-mir-17-5p, hsa-mir-181a-5p, hsa-mir-18a-5p, and hsa-mir-92a-1-5p, as signature regulators for autism using important genes and mRNA–miRNA network. The importance of these key genes and miRNAs is confirmed by previous studies and enrichment analysis.ConclusionThis study suggests FA_gene and DMN_miRNA algorithms for biomarker discovery, which lead us to a list of important players in ASD with potential roles in the nervous system or neurological disorders that can be experimentally investigated as candidates for ASD diagnostic tests.

The correlation between copy number variation in Chromosome 14 and DNA methylation in Saudi autistic children.

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder that represents a range of aberrant behaviour symptoms such as repetitive behaviours and defects in social communication. The prevalence of ASD has been increasing worldwide and many studies have reported that both genetic and epigenetic factors play an important role in the etiology of this disorder. The aim of this study was to investigate the implementation of DNA methylation and Copy number variation (CNV) in the diagnosis of ASD. This study was carried out on 14 Saudi autistic children and four of their healthy siblings. Comparative genomic hybridization array was used to identify CNV in chromosome 14 and MethyLight qPCR was used to estimate levels of DNA methylation. The results identified CNVs in six cytobands in chromosome 14 for 13 out of 14 autistic samples: 14q11.1-q11.2, 14q11.2, 14q12, 14q21.1, 14q32.2, and 14q32.33. However, some of these cytobands were also found in normal samples with different sizes. Interestingly, chromosomal abnormalities in 14q11.1-q11.2 was only found in ASD samples. The result also showed an increase in methylation ratio of ASD samples in those CNV regions compared with their siblings. The findings suggest that CNV in 14q11.1-q11.2 might be a potential target in ASD diagnosis and further work is required to detect which biological pathways are affected.

Representativeness of autistic samples in studies recruiting through social media.

Survey‐based research with recruitment through online channels is a convenient way to obtain large samples and has recently been increasingly used in autism research. However, sampling from online channels may be associated with a high risk of sampling bias causing findings not to be generalizable to the autism population. Here we examined autism studies that have sampled on social media for markers of sampling bias. Most samples showed one or more indicators of sampling bias, in the form of reversed sex ratio, higher employment rates, higher education level, lower fraction of individuals with intellectual disability, and later age of diagnosis than would be expected when comparing with for example population study results from published research. Findings from many of the included studies are therefore difficult to generalize to the broader autism population. Suggestions for how research strategies may be adapted to address some of the problems are discussed.Lay SummaryOnline surveys offer a convenient way to recruit large numbers of participants for autism research. However, the resulting samples may not fully reflect the autism population. Here we investigated the samples of 36 autism studies that recruited participants online and found that the demographic composition tended to deviate from what has been reported about the autism population in previous research. The results may thus not be generalizable to autism in general.

Multiple Recurrent Copy Number Variations (CNVs) in Chromosome 22 Including 22q11.2 Associated with Autism Spectrum Disorder.

IntroductionAutism spectrum disorder (ASD) is a developmental disorder that can cause substantial social, communication, and behavioral challenges. Genetic factors play a significant role in ASD, where the risk of ASD has been increased for unclear reasons. Twin studies have shown important evidence of both genetic and environmental contributions in ASD, where the level of contribution of these factors has not been proven yet. It has been suggested that copy number variation (CNV) duplication and the deletion of many genes in chromosome 22 (Ch22) may have a strong association with ASD. This study screened the CNVs in Ch22 in autistic Saudi children and assessed the candidate gene in the CNVs region of Ch22 that is most associated with ASD.MethodsThis study included 15 autistic Saudi children as well as 4 healthy children as controls; DNA was extracted from samples and analyzed using array comparative genomic hybridization (aCGH) and DNA sequencing.ResultsThe aCGH detected (in only 6 autistic samples) deletion and duplication in many regions of Ch22, including some critical genes. Moreover, DNA sequencing determined a genetic mutation in the TBX1 gene sequence in autistic samples. This study, carried out using aCGH, found that six autistic patients had CNVs in Ch22, and DNA sequencing revealed mutations in the TBX1 gene in autistic samples but none in the control.ConclusionCNV deletion and the duplication of the TBX1 gene could be related to ASD; therefore, this gene needs more analysis in terms of expression levels.

Clinical autism subscales have common genetic liabilities that are heritable, pleiotropic, and generalizable to the general population

The complexity of autism’s phenotypic spectra is well-known, yet most genetic research uses case-control status as the target trait. It is undetermined if autistic symptom domain severity underlying this heterogeneity is heritable and pleiotropic with other psychiatric and behavior traits in the same manner as autism case-control status. In N = 6064 autistic children in the SPARK cohort, we investigated the common genetic properties of twelve subscales from three clinical autism instruments measuring autistic traits: the Social Communication Questionnaire (SCQ), the Repetitive Behavior Scale-Revised (RBS-R), and the Developmental Coordination Disorder Questionnaire (DCDQ). Educational attainment polygenic scores (PGS) were significantly negatively correlated with eleven subscales, while ADHD and major depression PGS were positively correlated with ten and eight of the autism subscales, respectively. Loneliness and neuroticism PGS were also positively correlated with many subscales. Significant PGS by sex interactions were found—surprisingly, the autism case-control PGS was negatively correlated in females and had no strong correlation in males. SNP-heritability of the DCDQ subscales ranged from 0.04 to 0.08, RBS-R subscales ranged from 0.09 to 0.24, and SCQ subscales ranged from 0 to 0.12. GWAS in SPARK followed by estimation of polygenic scores (PGS) in the typically-developing ABCD cohort (N = 5285), revealed significant associations of RBS-R subscale PGS with autism-related behavioral traits, with several subscale PGS more strongly correlated than the autism case-control PGS. Overall, our analyses suggest that the clinical autism subscale traits show variability in SNP-heritability, PGS associations, and significant PGS by sex interactions, underscoring the heterogeneity in autistic traits at a genetic level. Furthermore, of the three instruments investigated, the RBS-R shows the greatest evidence of genetic signal in both (1) autistic samples (greater heritability) and (2) general population samples (strongest PGS associations).

The relevance of the interpersonal theory of suicide for predicting past-year and lifetime suicidality in autistic adults

BackgroundWhile there are known risk factors for suicidality in autistic adults, these are often unconnected from theoretical frameworks that might explain why risk is elevated and guide clinical interventions. The present study investigated the relevance of constructs from the Interpersonal Theory of Suicide (ITS), including perceived burdensomeness, thwarted belongingness and acquired capability for suicide, and explored mechanisms through which certain risk factors (relationship status, age at diagnosis) might elevate suicide risk.MethodsAutistic adults (n = 314) completed an online study including measures of depression, anxiety and constructs from the ITS. Linear and multinomial regression analysis disentangled contributions of ITS variables from effects of depression and anxiety for past-year suicide ideation, past-year and lifetime suicide attempts. Mediation analyses examined associations between risk factors and these suicide outcomes via mechanisms proposed by the ITS.ResultsPast-year suicide ideation was associated with burdensomeness, mental rehearsal of suicide plans (a facet of acquired capability), and depression. Greater feelings of burdensomeness, and reduced fear of death, marked out participants who had attempted suicide in comparison to those who had experienced suicide ideation in the past year. Relationship status was indirectly associated with past-year suicide ideation via the mediators of depression and burdensomeness, and was associated with past-year attempts via its effect on ideation. Age at diagnosis was unrelated to any variables.LimitationsCross-sectional research is insensitive to causality and temporal dynamics, which is likely why interaction hypotheses from the ITS were unsupported. Normative measures may be invalid in autistic samples. There was no control group. The autistic sample was unrepresentative of the whole population, particularly autistic people with intellectual disabilities, ethnic/racial minorities, and gender minorities.ConclusionsPerceived burdensomeness and acquired capability appear potentially important to suicide in autistic people, and may mediate the effects of some risk factors. Future research should explore the temporal dynamics of suicide trajectories in longitudinal, prospective designs.

Alexithymia may explain the relationship between autistic traits and eating disorder psychopathology

BackgroundAutistic people are disproportionately vulnerable to anorexia nervosa and other eating disorders (ED), and within the general population, autistic traits correlate with ED psychopathology. A putative mechanism which may underpin this heightened risk is alexithymia, a difficulty identifying and describing emotional states which is observed in both autism and ED. In two experiments with independent non-clinical samples, we explored whether alexithymia might mediate the heightened risk of eating psychopathology in individuals high in autistic traits.MethodsOur first experiment used the PROCESS macro for SPSS to examine relationships between alexithymia (measured by the Toronto Alexithymia Scale (TAS-20)), autistic traits (autism quotient (AQ)), and eating psychopathology (Eating Attitudes Test (EAT-26)) in 121 participants. Our second experiment (n = 300) replicated and furthered this analysis by examining moderating effects of sex and controlling for anxiety and depression as covariates. We also included an additional performance-based measure of alexithymia, the Levels of Emotional Awareness Scale (LEAS).ResultsStudy 1 suggested that TAS-20 scores mediated the relationship between heightened autistic traits and eating psychopathology. Replication and further scrutiny of this finding, in study 2, revealed that this mediation effect was partial and specific to the female participants in this sample. The mediation effect appeared to be carried by the difficulty identifying feelings subscale of the TAS-20, even when depression and anxiety were controlled for. LEAS scores, however, were not significantly related to autistic traits or eating psychopathology.LimitationsCross-sectional data prevents any conclusions around the direction and causality of relationships between alexithymia, autistic traits, and eating psychopathology (alongside depression and anxiety), necessitating longitudinal research. Our non-clinical sample was predominantly Caucasian undergraduate students, so it remains to be seen if these results would extrapolate to clinical and/or autistic samples. Divergence between the TAS-20 and LEAS raises crucial questions regarding the construct validity of these measures.ConclusionsOur findings with respect to autistic traits suggest that alexithymia could partially explain the prevalence of ED in autistic people and may as such be an important consideration in the pathogenesis and treatment of ED in autistic and non-autistic people alike. Further research with clinical samples is critical to explore these ideas. Differences between men and women, furthermore, emphasize the importance of looking for sex-specific as well as generic risk factors in autistic and non-autistic men and women.

Facial emotion recognition in autistic adult females correlates with alexithymia, not autism.

Research on predominantly male autistic samples has indicated that impairments in facial emotion recognition typically associated with autism spectrum conditions are instead due to co-occurring alexithymia. However, whether this could be demonstrated using more realistic facial emotion recognition stimuli and applied to autistic females was unclear. In all, 83 females diagnosed with autism spectrum condition completed online self-report measures of autism spectrum condition severity and alexithymia, and afacial emotion recognition deficit that assessed their ability to identify multimodal displays of complex emotions. Higher levels of alexithymia, but not autism spectrum condition severity, were associated with less accurate facial emotion recognition. Difficulty identifying one’s own feelings and externally oriented thinking were the components of alexithymia that were specifically related to facial emotion recognition accuracy. However, alexithymia (and autism spectrum condition severity) was not associated with speed of emotion processing. The findings are primarily discussed with the theoretical view that perceiving and experiencing emotions share the same neural networks, thus being able to recognise one’s own emotions may facilitate the ability to recognise others’. This study is in line with previous similar research on autistic males and suggests impairments in facial emotion recognition in autistic females should be attributed to co-occurring alexithymia.Lay abstractResearch with autistic males has indicated that difficulties in recognising facial expressions of emotion, commonly associated with autism spectrum conditions, may instead be due to co-occurring alexithymia (a condition involving lack of emotional awareness, difficulty describing feelings and difficulty distinguishing feelings from physical bodily sensations) and not to do with autism. We wanted to explore if this would be true for autistic females, as well as to use more realistic stimuli for emotional expression. In all, 83 females diagnosed with autism spectrum condition completed self-report measures of autism spectrum condition traits and alexithymia and completed a visual test that assessed their ability to identify multimodal displays of complex emotions. Higher levels of alexithymia, but not autism spectrum condition features, were associated with less accuracy in identifying emotions. Difficulty identifying one’s own feelings and externally oriented thinking were the components of alexithymia that were specifically related to facial emotion recognition accuracy. However, alexithymia (and levels of autism spectrum condition traits) was not associated with speed of emotion processing. We discuss the findings in terms of possible underlying mechanisms and the implications for our understanding of emotion processing and recognition in autism.

Mindfulness-Based Stress Reduction for Adults with Autism Spectrum Disorder: Feasibility and Estimated Effects

Adults with autism spectrum disorder (ASD) consistently report lower quality of life (QOL) compared with peers. Despite the growing population and needs of adults with ASD, many psychosocial interventions target children and adolescents while relying on high-level cognitive strategies for symptom reduction. Mindfulness-Based Stress Reduction (MBSR), which cultivates awareness and regulation skills through experiential practice instead of cognitive strategies, has been modified for autistic samples across the lifespan. However, it has not been tested if the standard MBSR curriculum is appropriate for an autistic population to improve QOL. This pilot feasibility trial aimed to (1) establish the feasibility and acceptability of a MBSR group intervention with adults diagnosed with ASD without modification; (2) evaluate fidelity to the MBSR curriculum; and (3) calculate estimates of change in QOL, life satisfaction, positive outlook, and mindfulness. Participants included twelve adults with ASD (IQ > 70; age 22–63). Participants completed the intervention and pre-, mid-, and post-assessments. Participants reported high satisfaction with the intervention on CSQ-8 (M = 27.92, SD = 3.5) with 100% retention. Randomly selected sessions met fidelity review on the MBI-TAC. Effect size estimates suggested large improvements in positive outlook (F(2,22) = 12.42, p < .001, d = 2.12), satisfaction with life (F(2,22) = 3.22, p = .059, d = 1.08), mindfulness (F(2,22) = 3.34, p = .054, d = 1.10), and quality of life (F(2,22) = 3.09, p = .066, d = 1.059). This study established feasibility and acceptability of traditional MBSR for adults with ASD and identified key supports for implementing MBSR with ASD.

Separate contributions of autistic traits and anxious apprehension, but not alexithymia, to emotion processing in faces.

Reduced eye fixation has been commonly reported in autistic samples but may be at least partially explained by alexithymia (i.e., difficulty understanding and describing one's emotional state). Because anxiety is often elevated in autism, and emotion-processing differences have also been observed in anxious samples, anxiety traits may also influence emotion processing within autism. This study tested the contribution of dimensional traits of autism, anxious apprehension, and alexithymia in mediating eye fixation during face processing. Participants included 105 adults from three samples: autistic adults (AS; n = 30), adults with clinically elevated anxiety and no autism (HI-ANX; n = 29), and neurotypical adults without elevated anxiety (NT; n = 46). Experiment 1 used an emotion identification task with dynamic stimuli, while Experiment 2 used a static luminance change detection task with emotional- and neutral-expression static photos. The emotions of interest were joy, anger, and fear. Dimensional mixed-effects models showed that autism traits, but not alexithymia, predicted reduced eye fixation across both tasks. Anxious apprehension was negatively related to response time in Experiment 1 and positively related to eye fixation in Experiment 2. Attentional avoidance of negative stimuli occurred at lower levels of autism traits and higher levels of worry traits. The results highlight the contribution of autism traits to emotional processing and suggest additional effects of worry-related traits.

Decision-Level Fusion-Based Structure of Autism Diagnosis Using Interpretation of EEG Signals Related to Facial Expression Modes

A structure of decision-level fusion-based autism diagnosis using analysis of EEG signals related to presentation of facial expression modes has been proposed. EEG signals of autistic and normal children were recorded during processing images of emotional facial expression modes, such as sadness, happiness, and calmness. Then brain signals were mapped into the feature space by applying a novel hybrid model utilizing the brain potentials recorded during the examination task. The aim of mapping was to achieve separation of the autistic samples from normal ones with the highest precision. The created map provides the feature vectors that reflected spatial, temporal, and spectral data, as well as the coherence degrees for distinct areas of the brain. The mapping process was optimized using a genetic algorithm by assigning weighs to the feature vectors. Then the feature vectors corresponding to the three facial expressions of emotional modes were classified by support vector machines. Finally, using decision-level fusion through a majority voting rule, we see that the proposed structure is able to effectively distinguish the autistic individuals from normal ones.

Associations between compulsive internet use and the autism spectrum

The increasingly complex relationship between individuals and online environments has prompted research exploring the potential for compulsive Internet use (CIU) in varying populations. Identification of the determinants of CIU, such as offline social difficulties associated with autism spectrum disorder (ASD), could clarify whether individuals compensate for offline difficulties through online interactions. In Study 1, 597 undergraduates took an online survey measuring CIU, social symptoms of ASD, restricted interests and repetitive behaviors (RIRB), self-esteem, and Facebook behaviors. A relationship between CIU and autistic traits was attributable to non-social characteristics (RIRB) and a relationship was identified between RIRB and information-seeking behaviors. These results complicate the social compensation hypothesis by suggesting that non-social personality characteristics contribute more strongly to CIU than individuals’ attempts to compensate for offline social challenges. Study 2 matched a sample of students with ASD (n=33) to neurotypical students (n=33) and uncovered no significant differences in CIU scores between the matched samples. These results suggest that findings observed by measuring autistic traits in neurotypical samples may not replicate with autistic samples.

Automated Vocal Analysis of Children With Hearing Loss and Their Typical and Atypical Peers.

This study investigated automatic assessment of vocal development in children with hearing loss compared with children who are typically developing, have language delays, and have autism spectrum disorder. Statistical models are examined for performance in a classification model and to predict age within the four groups of children. The vocal analysis system analyzed 1913 whole-day, naturalistic acoustic recordings from 273 toddlers and preschoolers comprising children who were typically developing, hard of hearing, language delayed, or autistic. Samples from children who were hard of hearing patterned more similarly to those of typically developing children than to the language delayed or autistic samples. The statistical models were able to classify children from the four groups examined and estimate developmental age based on automated vocal analysis. This work shows a broad similarity between children with hearing loss and typically developing children, although children with hearing loss show some delay in their production of speech. Automatic acoustic analysis can now be used to quantitatively compare vocal development in children with and without speech-related disorders. The work may serve to better distinguish among various developmental disorders and ultimately contribute to improved intervention.

Hypermethylation of the enolase gene (ENO2) in autism.

It has been hypothesized that dysregulation of brain-expressed genes is the major predisposing underlying mechanism for autism. This dysregulation may be mediated by differential methylation of CpG sites within gene promoters, which could be candidate biomarkers and used for early clinical screening of autism. A total of 131 pairs of age- and sex-matched autistic and control subjects were recruited in this study. Peripheral blood cells were analyzed. The first five pairs were randomly applied to array-based genome-wide methylation studies. A neuron-specific gene, ENO2, was found to be hypermethylated in the autistic samples. This difference was validated by bisulfite sequencing PCR (BSP). The differential expression of ENO2 gene was further analyzed with RT-qPCR and ELISA. The hypermethylation of ENO2 within the promoter region was confirmed by BSP to be present in 14.5 % (19/131) of the total of the autistic samples. The mean ENO2 RNA level in these 19 autistic samples was reduced by about 70 % relative to that in controls. The average level of ENO2 protein expression in the 19 autistic samples (15.18 ± 3.51 μg/l) was about half of that in the controls (33.86 ± 8.16 μg/l). Conclusion: These findings suggest that reduced ENO2 expression may be a biomarker for a subset of autistic children.Electronic supplementary materialThe online version of this article (doi:10.1007/s00431-014-2311-9) contains supplementary material, which is available to authorized users.