Measuring autistic traits in the general population: a systematic review of the Autism-Spectrum Quotient (AQ) in a nonclinical population sample of 6,900 typical adult males and females

Examining the Rate of Self-Reported ADHD-Related Traits and Endorsement of Depression, Anxiety, Stress, and Autistic-Like Traits in Australian University Students

OBJECTIVE

To investigate the rate of ADHD-related traits among young adults in an Australian university, and to examine whether higher endorsement of ADHD-related symptoms is associated with self-reported symptoms of depression, anxiety, distress, and autistic-like traits.

METHOD

In total, 1,002 students aged 17 to 25 years completed the Conners' Adult ADHD Rating Scale (CAARS), the Depression, Anxiety, and Stress Scale (DASS), and the Autism Quotient (AQ).

RESULTS

About 17.3% of students reported "at-risk" levels of ADHD-related symptoms. Regression analyses revealed that CAARS scores explained unique variance in self-reported levels of depression, anxiety, stress, and autism-related traits.

CONCLUSION

The rate of self-reported ADHD symptoms is higher in Australian undergraduate students than that reported in previous studies using the CAARS to investigate rates of diagnosed students. Problems with self-concept accounted for the most unique variance in DASS subscale scores. Hyperactivity/restlessness and inattention/memory problems accounted for the most unique variance in AQ-Social and AQ-Attention-to-Detail scores, respectively.

Animal Faux Pas: Two Legs Good Four Legs Bad for Theory of Mind, but Not in the Broad Autism Spectrum

Research shows that the general population varies with regard to both autistic traits and theory of mind (ToM) ability. Other work has shown that autistic individuals may not underperform on ToM tests when the agent of evaluation is anthropomorphic rather than typically human. Two studies examined the relation between ToM and autistic trait profiles in over 650 adults using either the standard Faux Pas Recognition Test (FPT) or an anthropomorphized version of the FPT (FPTa). Results showed that autistic trait profiles were related to faux pas detection ability in the FPT but not the FPTa. Furthermore, while those with the broad autism phenotype scored significantly worse than those who were typically developed on the FPT, scores did not significantly differ on the FPTa. These findings add to a growing body of work suggesting that ToM ability is not at a global deficit in those on the autistic spectrum, but may relate to the mindreading of specifically human agents.

Oral dysesthesia associated with autistic traits: a retrospective chart review

Oral dysesthesia denotes a condition characterized by abnormal sensations in oral regions without a somatic basis, and is often seen in people with autistic traits, including those with autism spectrum disorder. This study aimed to examine the association between the symptoms of oral dysesthesia and the degree of autistic traits. A retrospective chart review was performed on 44 patients with oral dysesthesia, and associations among the subscales of the Oral Dysesthesia Rating Scale (Oral DRS), Autism Spectrum Quotient (AQ), and Glasgow Sensory Questionnaire (GSQ) were investigated. A Pearson correlation analysis revealed a significant, positive correlation between AQ scores and the A3 (squeezing or pulling) subscale of the Oral DRS (r = 0.37), but there were no significant correlations between the AQ and other subscale scores. There was a significant correlation between the AQ and GSQ score, but no correlation was detected between the GSQ and A3 scores or any other Oral DRS subscale scores. In conclusion, an abnormal squeezing or pulling sensation in oral regions without a somatic basis was associated with autistic traits and could be highlighted as a specific abnormality in sensory processing in autism spectrum disorder.

Gender Difference in the Association Between Executive Function and Autistic Traits in Typically Developing Children

Autistic traits and executive function (EF) were assessed in 413 typically developing children aged 6-9 years. The children were divided into the high- autistic-trait (HAT) and low-autistic-trait (LAT) groups based on their total autistic traits. Results suggested that there were gender differences in specific autistic traits in children with LAT. There were gender-specific associations between EF and autistic traits in children with HAT: the set shifting of EF predicted difficulties in social awareness in boys; whereas all the EF components predicted difficulties in social communication and social cognition in girls. These findings may have implications for developing customized interventions that are targeted at specific autistic deficits in males and females.

Measuring Autism Traits in the Adult General Population with the Brief Autism-Spectrum Quotient, AQ-10: Findings from the Stockholm Public Health Cohort

BACKGROUND

The autism-spectrum quotient scale was developed to study autism as a spectrum. Few studies have examined the psychometric properties of the 10 item AQ (AQ-10). We examine the AQ-10 measurement ability and convergent validity in a population health survey (n = 44,722).

METHODS

The item severity and item discrimination was assessed using item response theory. Convergent validity was assessed by regressing on ADHD, psychological distress (PD) and having an education in the sciences.

RESULTS

Whilst unidimensional, the AQ-10 had some poorly fitting items. Item discrimination ranged from very low to very high. The scale correlated as hypothesised with the regress expected when factoring in ADHD, PD and possessing an eduction in the sciences.

CONCLUSION

The AQ-10 has adequate validity in the present sample and may be used in s as a measure of autistic traits. In Conclusion, The AQ-10 has adequate validity to be used in health surveys as a measure of autistic traits, although some items may perform poorly.

A 'choice', an 'addiction', a way 'out of the lost': exploring self-injury in autistic people without intellectual disability

Background

Non-suicidal self-injury (NSSI) describes a phenomenon where individuals inflict deliberate pain and tissue damage to their bodies. Self-injurious behaviour is especially prevalent across the autism spectrum, but little is understood about the features and functions of self-injury for autistic individuals without intellectual disability, or about the risk factors that might be valuable for clinical usage in this group.

Methods

One hundred and three autistic adults who responded to an online advertisement were classified as current, historic or non-self-harmers in accordance with responses to the Non-Suicidal Self-Injury Assessment Tool (NSSI-AT). Multinomial regression aimed to predict categorisation of participants in accordance with scores on tests of autistic traits, alexithymia, depression, anxiety, mentalising and sensory sensitivity. Linear regression examined relationships between these predictors and the range, frequency, lifetime occurrence and functional purposes of NSSI. Qualitative analysis explored the therapeutic interventions that participants had found helpful, and what they wished people understood about self-injury.

Results

Current, historic and non-self-harming participants did not differ in age, age at diagnosis, male-to-female ratio, level of employment or education (the majority qualified to at least degree level). The most common function of NSSI was the regulation of low-energy affective states (depression, dissociation), followed by the regulation of high-energy states such as anger and anxiety. Alexithymia significantly predicted the categorisation of participants as current, historic or non-self-harmers, and predicted use of NSSI for regulating high-energy states and communicating distress to others. Depression, anxiety and sensory-sensitivity also differentiated participant groups, and sensory differences also predicted the range of bodily areas targeted, lifetime incidence and frequency of NSSI. Sensory differences, difficulty expressing and identifying emotions also emerged as problematic in the qualitative analysis, where participants expressed the need for compassion, patience, non-judgement and the need to recognise diversity between self-harmers, with some participants perceiving NSSI as a practical, non-problematic coping strategy.

Conclusions

Alexithymia, depression, anxiety and sensory differences may place some autistic individuals at especial risk of self-injury. Investigating the involvement of these variables and their utility for identification and treatment is of high importance, and the voices of participants offer guidance to practitioners confronted with NSSI in their autistic clients.

Autistic Traits Are Associated With Decreased Activity of Fast Sleep Spindles During Adolescence

STUDY OBJECTIVES

Autistic traits present a continuum from mild symptoms to severe disorder and have been associated with a high prevalence of sleep problems. Sleep spindles have a key function in sleep maintenance and in brain plasticity. Previous studies have found decreased spindle activity in clinical autism. Here we examine the associations between the entire range of autistic traits and sleep spindle activity in a nonclinical community cohort of adolescents.

METHODS

Our cohort is based on 172 adolescents born in 1998 (58.7% girls, mean age = 16.9 years, standard deviation = 0.1), who filled in the adult autism-spectrum quotient (AQ), consisting of total score, and social interaction and attention to details subscales. Participants underwent an ambulatory overnight sleep electroencephalography. Sleep spindles (amplitude, duration, density, and intensity) were automatically detected from stage N2 sleep, and divided to slow and fast spindles.

RESULTS

Higher AQ total sum and social interaction sum associated with lower fast spindle amplitude and intensity (P < .04). No associations were observed for attention to details.

CONCLUSIONS

Our findings indicate that a higher level of autistic traits in the nonclinical range among generally healthy adolescents associate with similar alterations in sleep spindle activity as observed in many neuropsychiatric conditions, indicating lower sleep-related brain plasticity. This indicates that sleep microstructures form a continuum that follows self-reported symptoms of autism.

Judging social interaction in the Heider and Simmel movie

Simple displays of moving shapes can give rise to percepts of animacy. These films elicit impoverished narratives in some individuals, such as those with an autism spectrum disorder. However, the verbal demand of producing a narrative limits the utility of this task. Non-verbal tasks have so far focused on detecting animate objects. Lacking from previous research is a task that relies less on verbal description but more than animacy perception. Here, we presented data using a new social interaction judgement task. Healthy young adults viewed the Heider and Simmel movie and pressed one button whenever they perceived social interaction and another button when no social interaction was perceived. We measured the time points at which social judgement began, the fluctuation of the judgement in relation to stimulus kinematic properties, and the overall mean of social judgement. Participants with higher autism traits reported lower levels of social interaction. Reversing the film in time produced lower social interaction judgements, though the temporal profile was preserved. Our study suggests that both low-level motion characteristics and high-level understanding contribute to social interaction judgement. The finding may facilitate future research on other populations and stimulate computational vision work on factors that drive social judgements.

Examining the Diagnostic Validity of Autism Measures Among Adults in an Outpatient Clinic Sample

Background

Previous research has questioned the validity of diagnostic measures for autism spectrum disorder (ASD) among adults. This study examined the correspondence between several measures and clinician diagnosis.

Methods

We conducted a retrospective chart review for 93 adults (18-61 years; 72% male) who received an ASD evaluation at a specialty outpatient clinic. Thirty-one individuals (33%) in the sample were diagnosed with ASD. We compared participant scores on the Autism Spectrum Quotient (AQ), the Ritvo Autism Asperger's Diagnostic Scale-Revised (RAADS-R), and the Autism Diagnostic Observation Schedule (ADOS) to clinician diagnosis of ASD. We calculated sensitivity, specificity, and area under the curve (AUC) for each measure.

Results

Participants diagnosed with ASD scored significantly higher, on average, on the ADOS than those who were not diagnosed with ASD, but not on the RAADS-R or AQ. The AUC was relatively low for each measure: ADOS = 0.69 (95% confidence interval [CI] 0.58-0.81), RAADS-R = 0.58 (95% CI 0.46-0.72), and AQ = 0.40 (95% CI 0.28-0.52). Sensitivity and specificity of all three measures were in the poor to fair range. When dichotomized at the optimal cutoffs for this sample, the ADOS had a sensitivity of 0.65 and a specificity of 0.76; the RAADS-R had a sensitivity of 0.52 and a specificity of 0.73; and the AQ had a sensitivity of 0.45 and a specificity of 0.52.

Conclusions

Results of the study suggest that clinicians should not rely solely on self-report measures or the ADOS when diagnosing adults on the spectrum. Further development of measures is needed, including self-report measures with higher diagnostic validity, that are sensitive across age, gender, and cognitive functioning, and that differentiate autism from psychiatric diagnoses.

Lay Summary

Why was this study done?: Diagnosing adults with autism spectrum disorder (ASD) is difficult. Other research has suggested that the few measures that exist for autistic adults may not be very effective for accurate diagnoses. We wanted to see how closely the results of commonly used ASD assessment tools compared with clinical diagnoses in a real-life outpatient setting.What did the researchers do?: This study looked at adults who went to an adult ASD outpatient clinic for an initial ASD diagnosis over 3 years. Of these 93 adults, one-third were diagnosed as autistic. As part of the evaluation, all participants completed two commonly used autism screening surveys-the Autism Spectrum Quotient (AQ) and the Ritvo Autism Asperger's Diagnostic Scale-Revised (RAADS-R)-and took part in a semistructured diagnostic interview called the Autism Diagnostic Observation Schedule (ADOS). The clinicians also collected additional information and, when possible, spoke to family members before jointly making a diagnosis. The researchers compared how those diagnosed with ASD and those who were not diagnosed with ASD scored on the AQ, the RAADS-R, and the ADOS.What were the results of this study?: Although adults on the spectrum scored higher on average on the ADOS clinical interview than those who did not receive an autism diagnosis, they did not score higher on the AQ and RAADS-R self-report measures. All three of the measures were only moderately effective at showing who would be diagnosed with ASD and who was not.What do these findings add to what was already known?: These results confirm and expand on findings from other prior studies. The findings suggest that ASD diagnostic measures should not be used alone or considered the only source of information when making an initial autism diagnosis in adulthood.What are potential weaknesses in the study?: When studying the accuracy of diagnostic tests, it is best to compare the results of the tests being studied with an "independent gold standard," that is, a test that we know is very good and that is totally separate from the tests being studied. In this case, there is no clear "gold standard," so we had to compare the tests with the next best thing-the clinicians' final decision about whether or not a client has a diagnosis of ASD. It is possible that the clinicians did not make the right diagnosis. Also, the diagnosis was not "independent" of the tests being studied, since the clinicians used the results of the tests to help make the diagnosis. Clinicians only diagnosed about one-third of adults in this study with ASD, whereas previous studies in community clinics have had a higher percentage of adults diagnosed; this factor may have influenced the measures' accuracy. Lastly, clinicians in this study did not assess clients for any other mental health conditions, which may have provided more information about the clients who were not diagnosed with ASD.How will these findings help autistic adults now or in the future?: The findings from this study suggest that none of these measures are very accurate on their own. Thus, we recommend multiple measures (interviews and questionnaires) should be used together when clinicians diagnose ASD in adulthood. Results of this study also suggest that measures for adults with ASD should be tested in real-world community clinics, so that clinicians and researchers see how the measures perform when used for initial diagnosis in adulthood.

Development and Validation of the Camouflaging Autistic Traits Questionnaire (CAT-Q)

There currently exist no self-report measures of social camouflaging behaviours (strategies used to compensate for or mask autistic characteristics during social interactions). The Camouflaging Autistic Traits Questionnaire (CAT-Q) was developed from autistic adults' experiences of camouflaging, and was administered online to 354 autistic and 478 non-autistic adults. Exploratory factor analysis suggested three factors, comprising of 25 items in total. Good model fit was demonstrated through confirmatory factor analysis, with measurement invariance analyses demonstrating equivalent factor structures across gender and diagnostic group. Internal consistency (α = 0.94) and preliminary test-retest reliability (r = 0.77) were acceptable. Convergent validity was demonstrated through comparison with measures of autistic traits, wellbeing, anxiety, and depression. The present study provides robust psychometric support for the CAT-Q.

Negatively phrased items of the Autism Spectrum Quotient function differently for groups with and without autism

The Autism Spectrum Quotient is a widely used instrument for the detection of autistic traits. However, the validity of comparisons of Autism Spectrum Quotient scores between groups may be threatened by differential item functioning. Differential item functioning entails a bias in items, where participants with equal values of the latent trait give different answers because of their group membership. In this article, items of the Autism Spectrum Quotient were studied for differential item functioning between different groups within a single sample (N = 408). Three analyses were conducted. First, using a Rasch mixture model, two latent groups were detected that show differential item functioning. Second, using a Rasch regression tree model, four groups were found that show differential item functioning: men without autism, women without autism, people 50 years and younger with autism, and people older than 50 years with autism. Third, using traditional methods, differential item functioning was detected between groups with and without autism. Therefore, group comparisons with the Autism Spectrum Quotient are at risk of being affected by bias. Eight items emerged that consistently show differences in response tendencies between groups across analyses, and these items were generally negatively phrased. Two often-used short forms of the Autism Spectrum Quotient, the AQ-28 and AQ-10, may be more suitable for group comparisons.

Trends in concept and nosology of autism spectrum disorder: A review

Autism Spectrum Disorder is a neurodevelopmental disorder characterized by persistent deficits in social communication, social interaction and restricted, repetitive patterns of behavior, interests or activities. The concept of autism has changed since its inception, from childhood schizophrenia to neuro-variation. These changes in concept have been accompanied by changes in the diagnostic threshold through which the 'case' of autism is identified. The occurrence of multiple changes in its diagnostic criteria over last 80 odd years opens up the possibility of challenges being posed to the existence of the disorder as it is today, with a possibility of newer conceptualization of autism coming up in the future. The potential consequences of the changes in its nosology and concept, such as those on the management and on prevalence estimation are some of the essential issues which need attention. In the current paper, we evaluate the evolution of the concept and nosology of autism with an overview of the accompanying impact of these changes.

A new machine learning model based on induction of rules for autism detection

Autism spectrum disorder is a developmental disorder that describes certain challenges associated with communication (verbal and non-verbal), social skills, and repetitive behaviors. Typically, autism spectrum disorder is diagnosed in a clinical environment by licensed specialists using procedures which can be lengthy and cost-ineffective. Therefore, scholars in the medical, psychology, and applied behavioral science fields have in recent decades developed screening methods such as the Autism Spectrum Quotient and Modified Checklist for Autism in Toddlers for diagnosing autism and other pervasive developmental disorders. The accuracy and efficiency of these screening methods rely primarily on the experience and knowledge of the user, as well as the items designed in the screening method. One promising direction to improve the accuracy and efficiency of autism spectrum disorder detection is to build classification systems using intelligent technologies such as machine learning. Machine learning offers advanced techniques that construct automated classifiers that can be exploited by users and clinicians to significantly improve sensitivity, specificity, accuracy, and efficiency in diagnostic discovery. This article proposes a new machine learning method called Rules-Machine Learning that not only detects autistic traits of cases and controls but also offers users knowledge bases (rules) that can be utilized by domain experts in understanding the reasons behind the classification. Empirical results on three data sets related to children, adolescents, and adults show that Rules-Machine Learning offers classifiers with higher predictive accuracy, sensitivity, harmonic mean, and specificity than those of other machine learning approaches such as Boosting, Bagging, decision trees, and rule induction.

The Impact of Autistic Traits on Self-Recognition of Body Movements

Despite the sparse visual information and paucity of self-identifying cues provided by point-light stimuli, as well as a dearth of experience in seeing our own-body movements, people can identify themselves solely based on the kinematics of body movements. The present study found converging evidence of this remarkable ability using a broad range of actions with whole-body movements. In addition, we found that individuals with a high degree of autistic traits showed worse performance in identifying own-body movements, particularly for simple actions. A Bayesian analysis showed that action complexity modulates the relationship between autistic traits and self-recognition performance. These findings reveal the impact of autistic traits on the ability to represent and recognize own-body movements.

Prenatal Risk for ASD: Fetal Cortisol Exposure Predicts Child Autism-Spectrum Disorder Symptoms

The etiology of autism spectrum disorder (ASD) is multifactorial and complex and likely involves interactions among genetic, epigenetic and environmental factors. With respect to environmental influences, a growing literature implicates intrauterine experiences in the origin of this pervasive developmental disorder. In this prospective longitudinal design, we examine the hypothesis that fetal exposure to maternal cortisol may confer ASD risk. In addition, because ASD is four times more prevalent in males than females and because sexually dimorphic responses to intrauterine experiences are commonly observed, we examine whether or not any associations differ by fetal sex. Maternal plasma cortisol was measured at 15, 19, 25, 31, and 37 weeks' gestation in a sample of 84 pregnant women. ASD symptoms were assessed in their 5-year old children with the Social Communication Questionnaire (SCQ). Fetal exposure to lower levels of maternal cortisol was associated with higher levels of ASD symptoms among boys only. The observed hypocortisolemic profile exhibited by these mothers may indicate a risk factor that precedes the stress of caregiving for a child with ASD and may not be solely a consequence of the stress of caregiving as previously thought. Further, these findings confirm the value of examining prenatal hormone exposures as predictors of ASD risk and support the premise that altered prenatal steroid exposures may play a role in the etiology of ASD.

Persistent primary reflexes affect motor acts: Potential implications for autism spectrum disorder

In typical motor development progress in use of goal-directed actions and communicative gestures depends on the inhibition of several primitive reflexes, especially those that involve the hand or mouth. This study explored the relationship between the persistence of primitive reflexes that involve the hand or mouth and the motor repertoire in a sample of 12- to 17-month-old infants. Moreover, since children with Autism Spectrum Disorders (ASD) often have difficulty in performing skilled movements and show poor gesture repertoire, and since ASD represents the upper extreme of a constellation of traits that may be continuously distributed in the general population, we investigated the relationship between the persistence of primitive reflexes in the same sample of infants and the subclinical autistic traits measured in their parents. Results revealed that the persistence of the primitive reflexes correlated with motor repertoire irrespective of infant's age, and it was greater among infants whose parents had more subclinical autistic traits. Our findings suggest that the persistence of primitive reflexes might alter the developmental trajectory of future motor ability and therefore their evaluation might be an early indicator of atypical development.

Testing the Empathizing-Systemizing theory of sex differences and the Extreme Male Brain theory of autism in half a million people

In the largest study to date of autistic traits, we test 10 predictions from the Empathizing–Systemizing (E-S) theory of sex differences and the Extreme Male Brain (EMB) theory of autism. We confirmed that typical females on average are more empathic, typical males on average are more systems-oriented, and autistic people on average show a “masculinized” profile. The strengths of the study are the inclusion of a replication sample and the use of big data. These two theories can be considered to have strong support. We demonstrate that D-scores (difference between E and S) account for 19 times the variance in autistic traits than do other demographic variables, including sex, underscoring the importance of brain types in autism.

The Empathizing–Systemizing (E-S) theory of typical sex differences suggests that individuals may be classified based on empathy and systemizing. An extension of the E-S theory, the Extreme Male Brain (EMB) theory suggests that autistic people on average have a shift towards a more masculinized brain along the E-S dimensions. Both theories have been investigated in small sample sizes, limiting their generalizability. Here we leverage two large datasets (discovery n = 671,606, including 36,648 autistic individuals primarily; and validation n = 14,354, including 226 autistic individuals) to investigate 10 predictions of the E-S and the EMB theories. In the discovery dataset, typical females on average showed higher scores on short forms of the Empathy Quotient (EQ) and Sensory Perception Quotient (SPQ), and typical males on average showed higher scores on short forms of the Autism Spectrum Quotient (AQ) and Systemizing Quotient (SQ). Typical sex differences in these measures were attenuated in autistic individuals. Analysis of “brain types” revealed that typical females on average were more likely to be Type E (EQ > SQ) or Extreme Type E and that typical males on average were more likely to be Type S (SQ > EQ) or Extreme Type S. In both datasets, autistic individuals, regardless of their reported sex, on average were “masculinized.” Finally, we demonstrate that D-scores (difference between EQ and SQ) account for 19 times more of the variance in autistic traits (43%) than do other demographic variables including sex. Our results provide robust evidence in support of both the E-S and EMB theories.

Syllogistic reasoning reveals reduced bias in people with higher autistic-like traits from the general population

Recent theories of autism have emphasised the cognitive strengths and weaknesses in those with autism, which are also seen to some degree in non-clinical samples with higher autistic-like traits. The dual process theory of autism proposes that people with autism and non-clinical people with a higher degree of autistic-like traits have a propensity to show reduced intuitive processing (automatic and typically faster) alongside enhanced propensity towards deliberative processing (dependent on general cognitive ability and typically slower). This study aimed to further test the dual process theory of autism by investigating syllogistic reasoning (whether a conclusion can be logically deduced from two propositions) in addition to the cognitive reflection test (correct responses to which reflect deliberative processing over-riding intuitive processing) with respect to the degree of autistic-like traits and general cognitive ability in a non-clinical sample of 189 adults. Results showed that higher levels of autistic-like traits were related to lower levels of intuitive processing and higher levels of deliberative processing, which was found across both the syllogistic reasoning and cognitive reflection test measures - over and above the effect of general cognitive ability. The findings are consistent with the dual process theory of autism, and implications for autism are discussed.

Autistic traits predict poor integration between top-down contextual expectations and movement kinematics during action observation

Autism is associated with difficulties in predicting and understanding other people’s actions. There is evidence that autistic traits are distributed across a spectrum and that subclinical forms of autistic impairments can also be measured in the typical population. To investigate the association between autistic traits and motor responses to others’ actions, we quantified these traits and measured cortico-spinal excitability modulations in M1 during the observation of actions embedded in congruent, incongruent and ambiguous contexts. In keeping with previous studies, we found that actions observed in congruent contexts elicited an early facilitation of M1 responses, and actions observed in incongruent contexts, resulted in a later inhibition. Correlational analysis revealed no association between autistic traits and the facilitation for congruent contexts. However, we found a significant correlation between motor inhibition and autistic traits, specifically related to social skills and attention to details. Importantly, the influence of these factors was independent from each other, and from the observer’s gender. Thus, results suggest that individuals with higher social deficits and greater detail-processing style are more impaired in suppressing action simulation in M1 when a mismatch between kinematics and context occurs. This points to difficult integration between kinematics and contextual representations in the autistic-like brain.

Does stereopsis account for the link between motor and social skills in adults?

Background

Experimental and longitudinal evidence suggests that motor proficiency plays an important role in the development of social skills. However, stereopsis, or depth perception, may also play a fundamental role in social skill development either indirectly through its impact on motor skills or through a more direct route. To date, no systematic study has investigated the relationship between social skills and motor ability in the general adult population, and whether poor stereopsis may contribute to this association. This has implications for clinical populations since research has shown associations between motor abnormalities and social skills, as well as reduced depth perception in autism spectrum disorder and developmental coordination disorder.

Methods

Six hundred fifty adults completed three validated questionnaires, the stereopsis screening inventory, the Adult Developmental Coordination Disorder Checklist, and the Autism Spectrum Quotient.

Results

An exploratory factor analysis on pooled items across all measures revealed 10 factors that were largely composed of items from a single scale, indicating that any co-occurrence of poor stereopsis, reduced motor proficiency, and difficulties with social interaction cannot be attributed to a single underlying mechanism. Correlations between extracted factor scores found associations between motor skill and social skill.

Conclusions

Mediation analyses suggested that whilst fine motor skill and coordination explained the relationship between stereopsis and social skill to some extent, stereopsis nonetheless exerted a substantial direct effect upon social skill. This is the first study to demonstrate that the functional significance of stereopsis is not limited to motor ability and may directly impact upon social functioning.

Infant quantitative risk for autism spectrum disorder predicts executive function in early childhood

Much of the current research concerning autism spectrum disorder (ASD) focuses on early identification of behaviors that may indicate future deficits or higher risk for a later diagnosis. Additionally, there exists a strong claim regarding the dimensional nature of ASD, such that even among non-diagnosed individuals, a continuous distribution of symptom severity can be observed. Executive function (EF) has been widely studied in children, adolescents, and adults with ASD, with a robust body of research supporting widespread EF deficits in diagnosed individuals. However, it remains unclear how the degree of ASD symptomatology, outside of the presence of a diagnosis, affects EF abilities in a community sample. The First Year Inventory 2.0 (FYI 2.0), a parent-report measure, was designed to identify infants at 12 months who are at risk for an eventual ASD diagnosis. In the current study, a continuous scoring scale was used to examine risk (overall, Social-Communication, and Sensory-Regulatory) from a dimensional perspective. Parents also completed the Behavior Rating Inventory of Executive Function-Preschool Version and the Social Responsiveness Scale-2nd edition when their children were 42 months (3.5 years) old. Each FYI 2.0 risk variable significantly predicted scores on an overall EF composite and specific EF subscales. When controlling for general ASD symptomatology, Sensory-Regulatory risk still significantly predicted EF deficits. This research provides additional support for a quantitative consideration of risk for ASD and presents novel findings regarding the relation between infant behaviors indicative of ASD risk and EF in early childhood. Autism Research 2018, 11: 1532-1541. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Children with autism spectrum disorder (ASD) often have difficulty with executive function (EF) tasks that require a set of mental processes involved in goal-directed behaviors. Studying children without ASD who may have symptoms affecting EF is also important. This study demonstrates that certain infant behaviors related to ASD are linked to early childhood EF difficulties. These results support looking at a range of ASD symptoms to better understand children who struggle with EF and potentially design tools to help them.

Transcranial direct current stimulation (tDCS) over right temporoparietal junction (rTPJ) for social cognition and social skills in adults with autism spectrum disorder (ASD)

Social deficits are core to autism spectrum disorder (ASD). Current treatments are extremely time- and labor-intensive. Transcranial direct current stimulation (tDCS) may be a promising treatment modality to safely enhance treatments targeting social cognition and social skills. This pilot study investigates the effectiveness of social skills treatment interventions paired with anodal tDCS for six adults 18-58 years with ASD. Differences were predicted on the verbal fluency (VF) test and a test of social skills (TASSK-M) for verum (2.0 mA) vs. sham tDCS, which was randomly assigned in a within-subjects, double-blinded design in adults with ASD with normal or higher cognitive functioning. The anode electrode was placed over right temporoparietal (CP6) and cathode over ipsilateral deltoid. Wilcoxon signed-rank tests for paired data indicated that participants received a significantly higher score on the VF test after receiving verum tDCS compared to sham tDCS, with no significant differences found on the TASSK-M. Post-hoc analysis showed that the emotion-word portion of the VF test, specifically, indicated significant differences when comparing verum to sham tDCS conditions. These findings provide optimism for the use of tDCS as delivered in the current study paired with social skills treatment interventions for ASD, particularly for improving skills of emotion verbal fluency.

Delayed autism spectrum disorder recognition in children and adolescents previously diagnosed with attention-deficit/hyperactivity disorder

Phenotypic elements of autism spectrum disorder can be masked by attention-deficit/hyperactivity disorder symptoms, potentially leading to a misdiagnosis or delaying an autism spectrum disorder diagnosis. This study explored differences in the age of autism spectrum disorder diagnosis between participants with previously diagnosed attention-deficit/hyperactivity disorder versus autism spectrum disorder–only respondents. Children and adolescents, but not adults, initially diagnosed with attention-deficit/hyperactivity disorder received an autism spectrum disorder diagnosis an average of 1.8 years later than autism spectrum disorder–only children, although the findings regarding the adult sample should be interpreted with caution. Gender differences were also explored, revealing that the delay in receiving an autism diagnosis was 1.5 years in boys and 2.6 years in girls with pre-existing attention-deficit/hyperactivity disorder, compared with boys and girls without prior attention-deficit/hyperactivity disorder. No significant gender differences were observed in the adult sample. We argue that overlapping symptoms between autism spectrum disorder and attention-deficit/hyperactivity disorder might delay a formal diagnosis of autism either by leading to a misdiagnosis of attention-deficit/hyperactivity disorder or by making it difficult to identify the presence of co-occurring autism spectrum disorder conditions once an initial diagnosis of attention-deficit/hyperactivity disorder has been obtained. Current findings highlight the need to recruit multidimensional and multidisciplinary screening procedures to assess for potential emerging autism spectrum disorder hallmarks in children and adolescents diagnosed or presenting with attention-deficit/hyperactivity disorder symptoms.

An accessible and efficient autism screening method for behavioural data and predictive analyses

Autism spectrum disorder is associated with significant healthcare costs, and early diagnosis can substantially reduce these. Unfortunately, waiting times for an autism spectrum disorder diagnosis are lengthy due to the fact that current diagnostic procedures are time-consuming and not cost-effective. Overall, the economic impact of autism and the increase in the number of autism spectrum disorder cases across the world reveal an urgent need for the development of easily implemented and effective screening methods. This article proposes a new mobile application to overcome the problem by offering users and the health community a friendly, time-efficient and accessible mobile-based autism spectrum disorder screening tool called ASDTests. The proposed ASDTests app can be used by health professionals to assist their practice or to inform individuals whether they should pursue formal clinical diagnosis. Unlike existing autism screening apps being tested, the proposed app covers a larger audience since it contains four different tests, one each for toddlers, children, adolescents and adults as well as being available in 11 different languages. More importantly, the proposed app is a vital tool for data collection related to autism spectrum disorder for toddlers, children, adolescent and adults since initially over 1400 instances of cases and controls have been collected. Feature and predictive analyses demonstrate small groups of autistic traits improving the efficiency and accuracy of screening processes. In addition, classifiers derived using machine learning algorithms report promising results with respect to sensitivity, specificity and accuracy rates.

Assessing Theory of Mind by Humor: The Humor Comprehension and Appreciation Test (ToM-HCAT)

Theory of Mind (ToM) may be defined as the ability to understand the mental states, such as beliefs, desires, intentions, and emotions, of others. Impairment of ToM ability leads to disorders with pathologies in social skills, such as autism spectrum disorder and schizophrenia. In addition to differences in ToM ability among patient populations, there is variation between neurotypical individuals. Unfortunately, ToM tasks are usually developed for children or patients with cognitive disorders and cannot detect variations in healthy adults. As an alternative tool, humor may be used. Humor plays a role in social communication and requires many different cognitive functions. Humor is believed to represent complex high-order cognitive processes. There are numerous types of humor; the most complex type is considered ToM humor, where an understanding of social/emotional content is necessary. Given the need for a ToM assessment test suitable for healthy adult populations, we developed a test for measuring humor comprehension and appreciation, with and without ToM content (ToM-HCAT). The present ToM-HCAT test is a performance test consisting of cartoons. The test measures perceived funniness, reaction time to perceived funniness decision, and meaning inference. Cartoons were selected after pilot studies involving 44 participants. Subscales were constituted according to expert views and confirmed by confirmatory factor analysis (N = 135). Goodness of fit values for the final 35-item test were acceptable to excellent: GFI = 0.97; AGFI = 0.97; NFI = 0.97; RFI = 0.97, and SRMR = 0.067. Both categories were internally consistent (α1 = 0.84, α2 = 0.94). External validity was assessed against autistic traits. One hundred and three participants completed the Autism Spectrum Quotient and were grouped by +0.5 standard deviations from the mean as high in autistic traits. The meaning-inference scores of the subscale with the ToM cartoons were significantly lower (p = 0.034) for the high autistic traits group, providing evidence of external validity. In conclusion, we developed and validated a test for assessment of ToM by humor comprehension and appreciation. We believe that the present test will be useful for the detection of variations in ToM ability in the healthy adult population.

The Reliability and Validity of the Korean Version of the Autism-Spectrum Quotient

OBJECTIVE

This study was conducted to investigate the reliability and validity of the Korean version of Autism-Spectrum Quotient (AQ).

METHODS

20 participants with high-functioning autism (HFA) and 99 normal participants were recruited. All participants were completed the AQ and Empathy Quotient (EQ), and parents of the HFA group completed the parent-report AQ. For testing the reliability, we examined Cronbach's alpha, performed item analysis, and compared self versus parent report score of HFA participants. For testing the validity, we compared the difference of the score of AQ among HFA and control group using independent t-tests, and performed correlation analysis between AQ and EQ. The receiver operation characteristic curve analysis was performed to determine a cut-off.

RESULTS

The Korean version of the AQ exhibited adequate internal consistency, and in most items, the HFA group scored higher in comparison to the control group. It was demonstrated that AQ has good discriminant validity through the confirmation of the significant difference in the AQ score between two groups. The concurrent validity was established through the significant correlation between AQ and EQ in the HFA group. The best estimate cut-off score of AQ for screening was 23.

CONCLUSION

The Korean version of the AQ was determined as a reliable and valid instrument to assess HFA in Korean population.

Risk markers for suicidality in autistic adults

Background

Research has shown high rates of suicidality in autism spectrum conditions (ASC), but there is lack of research into why this is the case. Many common experiences of autistic adults, such as depression or unemployment, overlap with known risk markers for suicide in the general population. However, it is unknown whether there are risk markers unique to ASC that require new tailored suicide prevention strategies.

Methods

Through consultation with a steering group of autistic adults, a survey was developed aiming to identify unique risk markers for suicidality in this group. The survey measured suicidality (SBQ-R), non-suicidal self-injury (NSSI-AT), mental health problems, unmet support needs, employment, satisfaction with living arrangements, self-reported autistic traits (AQ), delay in ASC diagnosis, and 'camouflaging' ASC. One hundred sixty-four autistic adults (65 male, 99 female) and 169 general population adults (54 males, 115 females) completed the survey online.

Results

A majority of autistic adults (72%) scored above the recommended psychiatric cut-off for suicide risk on the SBQ-R; significantly higher than general population (GP) adults (33%). After statistically controlling for a range of demographics and diagnoses, ASC diagnosis and self-reported autistic traits in the general population significantly predicted suicidality. In autistic adults, non-suicidal self-injury, camouflaging, and number of unmet support needs significantly predicted suicidality.

Conclusions

Results confirm previously reported high rates of suicidality in ASC, and demonstrate that ASC diagnosis, and self-reported autistic traits in the general population are independent risk markers for suicidality. This suggests there are unique factors associated with autism and autistic traits that increase risk of suicidality. Camouflaging and unmet support needs appear to be risk markers for suicidality unique to ASC. Non-suicidal self-injury, employment, and mental health problems appear to be risk markers shared with the general population that are significantly more prevalent in the autistic community. Implications for understanding and prevention of suicide in ASC are discussed.

Risk markers for suicidality in autistic adults

BACKGROUND

Research has shown high rates of suicidality in autism spectrum conditions (ASC), but there is lack of research into why this is the case. Many common experiences of autistic adults, such as depression or unemployment, overlap with known risk markers for suicide in the general population. However, it is unknown whether there are risk markers unique to ASC that require new tailored suicide prevention strategies.

METHODS

Through consultation with a steering group of autistic adults, a survey was developed aiming to identify unique risk markers for suicidality in this group. The survey measured suicidality (SBQ-R), non-suicidal self-injury (NSSI-AT), mental health problems, unmet support needs, employment, satisfaction with living arrangements, self-reported autistic traits (AQ), delay in ASC diagnosis, and 'camouflaging' ASC. One hundred sixty-four autistic adults (65 male, 99 female) and 169 general population adults (54 males, 115 females) completed the survey online.

RESULTS

A majority of autistic adults (72%) scored above the recommended psychiatric cut-off for suicide risk on the SBQ-R; significantly higher than general population (GP) adults (33%). After statistically controlling for a range of demographics and diagnoses, ASC diagnosis and self-reported autistic traits in the general population significantly predicted suicidality. In autistic adults, non-suicidal self-injury, camouflaging, and number of unmet support needs significantly predicted suicidality.

CONCLUSIONS

Results confirm previously reported high rates of suicidality in ASC, and demonstrate that ASC diagnosis, and self-reported autistic traits in the general population are independent risk markers for suicidality. This suggests there are unique factors associated with autism and autistic traits that increase risk of suicidality. Camouflaging and unmet support needs appear to be risk markers for suicidality unique to ASC. Non-suicidal self-injury, employment, and mental health problems appear to be risk markers shared with the general population that are significantly more prevalent in the autistic community. Implications for understanding and prevention of suicide in ASC are discussed.

Investigating Mirror System (MS) Activity in Adults with ASD When Inferring Others' Intentions Using Both TMS and EEG

ASD is associated with mentalizing deficits that may correspond with atypical mirror system (MS) activation. We investigated MS activity in adults with and without ASD when inferring others' intentions using TMS-induced motor evoked potentials (MEPs) and mu suppression measured by EEG. Autistic traits were measured for all participants. Our EEG data show, high levels of autistic traits predicted reduced right mu (8-10 Hz) suppression when mentalizing. Higher left mu (8-10 Hz) suppression was associated with superior mentalizing performances. Eye-tracking and TMS data showed no differences associated with autistic traits. Our data suggest ASD is associated with reduced right MS activity when mentalizing, TMS-induced MEPs and mu suppression measure different aspects of MS functioning and the MS is directly involved in inferring intentions.

No relationship between autistic traits and salivary testosterone concentrations in men from the general population

It is suggested that testosterone may play a part in the higher prevalence of Autism Spectrum Disorder (ASD) in males compared to females. Previous studies have reported elevated postnatal testosterone levels in children and women with ASD but not in men. We compared levels of salivary testosterone across 67 undergraduate males (M_age 19.5 yrs, SD 1.92) selected for low, mid-range and high levels of autistic traits assessed using the Autism-spectrum Quotient. Analyses revealed no significant differences in testosterone concentrations across the three groups. The current data add to the increasing evidence for the lack of relationship between autistic traits and postnatal levels of testosterone in men.

Broader autism phenotype in parents of children with autism: a systematic review of percentage estimates

The broader autism phenotype (BAP) is a collection of sub-diagnostic autistic traits more common in families of individuals with autism spectrum disorder (ASD) than in the general population. BAP is a latent construct that can be defined using different domains, measured using multiple instruments, and reported using different techniques. Therefore, estimates of BAP may vary greatly across studies. Our objective was to systematically review studies that reported occurrence of BAP in parents of children with ASD in order to quantify and describe heterogeneity in estimates. We systematically searched PubMed and Scopus using PRISMA guidelines for studies quantifying percentage of parents of children with ASD who had BAP We identified 41 studies that measured BAP in parents of children with ASD. These studies used eight different instruments, four different forms of data collection, and had a wide range of sample sizes (N=4 to N=3299). Percentage with BAP ranged from 2.6% to 80%. BAP was more prevalent in fathers than mothers. Parental BAP may be an important tool for parsing heterogeneity in ASD etiology and for developing parent-mediated ASD interventions. However, the variety in measurement instruments and variability in study samples limits our ability to synthesize estimates. To improve measurement of BAP and increase consistency across studies, universal methods should be accepted and adopted across studies. A more consistent approach to BAP measurement may enable efficient etiologic research that can be meta-analyzed and may allow for a larger evidence base that can be used to account for BAP when developing parent-mediated interventions.

Is Older Age Associated with Higher Self- and Other-Rated ASD Characteristics?

Autism spectrum disorder (ASD) characteristics seem to abate over time, but whether this protracts until late adulthood is largely unknown. We cross-sectionally investigated self- and other-reported ASD characteristics of adults with (ASD: Nmax-self = 237, Nmax-other = 130) and without ASD (COM: Nmax-self = 198, Nmax-other = 148) aged 19-79 years. Within the ASD group, self-reported ASD characteristics, and sensory sensitivities were highest in middle adulthood, while age was not associated to empathy. Sex differences were also found. However, age-and sex-related differences were not revealed by others and self- and other-report were poorly concordant. These results show that ASD characteristics in adulthood are differently perceived across age, sex, and informants and suggest that it is important to repeatedly assess self-reported ASD characteristics during adulthood.

Relating Attentional Biases for Stimuli Associated with Social Reward and Punishment to Autistic Traits

Evidence for impaired attention to social stimuli in autism has been mixed. The role of social feedback in shaping attention to other, non-social stimuli that are predictive of such feedback has not been examined in the context of autism. In the present study, participants searched for a color-defined target during a training phase, with the color of the target predicting the emotional reaction of a face that appeared after each trial. Then, participants performed visual search for a shape-defined target while trying to ignore the color of stimuli. On a subset of trials, one of the non-targets was rendered in the color of a former target from training. Autistic traits were measured for each participant using the Autism Quotient (AQ). Our findings replicate robust attentional capture by stimuli learned to predict valenced social feedback. There was no evidence that autistic traits are associated with blunted attention to predictors of social outcomes. Consistent with an emerging body of literature, our findings cast doubt on strong versions of the claim that autistic traits can be explained by a blunted influence of social information on the attention system. We extend these findings to non-social stimuli that predict socially relevant information.

Investigation of Broad Autism Phenotype Traits as Measured by the 26-Item Autism Quotient

The extant literature regarding psychometric properties of measures of subclinical adult autism traits is sparse. The current study investigated the validity and internal consistency reliability of the 26-item Autism Quotient (AQ-26), a self-report measure of autism traits, in a nonclinical young adult sample. Results indicated significantly better model fit with an 18-item measure (AQ-18), with optimal fit indices. Otherwise, AQ-18 and AQ-26 findings were similar and are discussed together. A three-factor model best fit the data. Scores demonstrated similar correlations in expected directions with the Empathy Quotient and Broad Autism Phenotype (BAP) Questionnaire. Expected differences were also observed when college major, gender, and BAP/non-BAP groups were compared. Despite somewhat weaker evidence for the 26/18-Details/Patterns factor, findings indicate that the AQ-26 and AQ-18 are promising measures of the three traits of subclinical autism spectrum symptomatology.

A prospective study of fetal head growth, autistic traits and autism spectrum disorder

Altered trajectories of brain growth are often reported in Autism Spectrum Disorder (ASD), particularly during the first year of life. However, less is known about prenatal head growth trajectories, and no study has examined the relation with postnatal autistic symptom severity. The current study prospectively examined the association between fetal head growth and the spectrum of autistic symptom severity in two large population-based cohorts, including a sample of individuals with clinically diagnosed ASD. This study included 3,820 children from two longitudinal prenatal cohorts in The Netherlands and Australia, comprising 60 individuals with a confirmed diagnosis of ASD. Latent growth curve models were used to examine the relationship between fetal head circumference measured at three different time points and autistic traits measured in postnatal life using either the Social Responsiveness Scale or the Autism-Spectrum Quotient. While lower initial prenatal HC was weakly associated with increasing autistic traits in the Dutch cohort, this relationship was not observed in the Australian cohort, nor when the two cohorts were analysed together. No differences in prenatal head growth were found between individuals with ASD and controls. This large population-based study identified no consistent association across two cohorts between prenatal head growth and postnatal autistic traits. Our mixed findings suggest that further research in this area is needed. Autism Res 2018, 11: 602-612. © 2018 The Authors Autism Research published by International Society for Autism Research and Wiley Periodicals, Inc.

LAY SUMMARY

It is not known whether different patterns of postnatal brain growth in Autism Spectrum Disorder (ASD) also occurs prenatally. We examined fetal head growth and autistic symptoms in two large groups from The Netherlands and Australia. Lower initial prenatal head circumference was associated with autistic traits in the Dutch, but not the Australian, group. No differences in head growth were found in individuals with ASD and controls when the data was combined. Our mixed findings suggest that more research in this area is needed.

Individual differences in developmental plasticity: A role for early androgens?

Developmental plasticity is a widespread property of living organisms, but different individuals in the same species can vary greatly in how susceptible they are to environmental influences. In humans, research has sought to link variation in plasticity to physiological traits such as stress reactivity, exposure to prenatal stress-related hormones such as cortisol, and specific genes involved in major neurobiological pathways. However, the determinants of individual differences in plasticity are still poorly understood. Here we present the novel hypothesis that, in both sexes, higher exposure to androgens during prenatal and early postnatal life should lead to increased plasticity in traits that display greater male variability (i.e., a majority of physical and behavioral traits). First, we review evidence of greater phenotypic variation and higher susceptibility to environmental factors in males; we then consider evolutionary models that explain greater male variability and plasticity as a result of sexual selection. These empirical and theoretical strands converge on the hypothesis that androgens may promote developmental plasticity, at least for traits that show greater male variability. We discuss a number of potential mechanisms that may mediate this effect (including upregulation of neural plasticity), and address the question of whether androgen-induced plasticity is likely to be adaptive or maladaptive. We conclude by offering suggestions for future studies in this area, and considering some research designs that could be used to empirically test our hypothesis.

Pupillometry reveals perceptual differences that are tightly linked to autistic traits in typical adults

The pupil is primarily regulated by prevailing light levels but is also modulated by perceptual and attentional factors. We measured pupil-size in typical adult humans viewing a bistable-rotating cylinder, constructed so the luminance of the front surface changes with perceived direction of rotation. In some participants, pupil diameter oscillated in phase with the ambiguous perception, more dilated when the black surface was in front. Importantly, the magnitude of oscillation predicts autistic traits of participants, assessed by the Autism-Spectrum Quotient AQ. Further experiments suggest that these results are driven by differences in perceptual styles: high AQ participants focus on the front surface of the rotating cylinder, while those with low AQ distribute attention to both surfaces in a more global, holistic style. This is the first evidence that pupillometry reliably tracks inter-individual differences in perceptual styles; it does so quickly and objectively, without interfering with spontaneous perceptual strategies.

Transcranial Direct Current Stimulation to the Right Temporoparietal Junction for Social Functioning in Autism Spectrum Disorder: A Case Report

OBJECTIVES

While there is evidence of improved social functioning after applying transcranial direct current stimulation (tDCS) at the right temporoparietal junction (rTPJ) in individuals who are healthy, no current studies have investigated the use of tDCS at the rTPJ to improve social functioning in individuals with autism spectrum disorder (ASD). This case investigates the use of tDCS applied to the rTPJ to target social functioning in a high-functioning adult with ASD.

METHODS

The authors present a case of an 18-year old patient with ASD treated successfully with tDCS; 1.5 mA of tDCS was applied once a day for 30 minutes for 8 consecutive days with the anode electrode over rTPJ (CP6 in the 10/10 electroencephalogram system) and the cathode electrode placed on the ipsilateral deltoid. Behavioral outcome was assessed using the Autism Treatment Evaluation Checklist prior to tDCS, after the final tDCS session, and at 2 months after tDCS. An additional, informal follow-up was also made 1 year after tDCS.

RESULTS

Autism Treatment Evaluation Checklist showed substantial improvement in social functioning from baseline to post-tDCS, which was maintained at 2 months. The patient also reported lessened feelings of anger and frustration over social disappointments. Informal follow-up 1 year after stimulation indicates that the patient continues to maintain many improvements.

CONCLUSIONS

Anodal tDCS to the rTPJ may represent an effective treatment for improving social functioning in ASD, with a larger clinical trial needed to validate this effect.

BDNF levels are associated with autistic traits in the general population

Evidence supports the notion that autistic symptoms and behaviors should be regarded as dimensional traits. The present study aimed to investigate the role of vasopressin (AVP), brain-derived neurotrophic factor (BDNF) and oxytocin (OXT) as potential biochemical correlates of subclinical autistic traits in a cohort of healthy young adults. One hundred and fifty-three subjects (80 males, 73 females) were recruited. Participants completed the Autism Spectrum Quotient (AQ), a widely used measure for the identification of autistic traits in the general population. Additionally, blood samples were obtained from all participants at the same time of the day to control for circadian variation. We conducted a multiple regression analysis using the AQ score as the dependent variable and age, sex, AVP, BDNF and OXT levels as the independent variables. The model explained approximately the 22% of the variance of the AQ score. Among the parameters included in the analysis, only BDNF levels were independent predictors of AQ score.

Lateral inhibition in the autism spectrum: An SSVEP study of visual cortical lateral interactions

Circuit level brain dysfunction has been suggested as a common mechanism through which diverse genetic risk factors and neurobiological sequelae lead to the core features of autism spectrum disorder (Geschwind 2009; Port et al. 2014). An important mediator of circuit level brain activity is lateral inhibition, and a number of authors have suggested that lateral inhibition may be atypical in ASD. However, evidence regarding putative atypical lateral connections in ASD is mixed. Here we employed a steady state visual evoked potential (SSVEP) paradigm to further investigate lateral connections within a group of high functioning adults with ASD. At a group level, we found no evidence of altered lateral interactions in ASD. Exploratory analyses reveal that greater ASD symptom severity (increased ADOS score) is associated with increased short range lateral inhibition. These results suggest that lateral interactions are not altered in ASD at a group-level, but that subtle alterations in such neurobiological processes may underlie the heterogeneity seen in the autism spectrum in terms of sensory perception and behavioral phenotype.

Child, Maternal and Demographic Factors Influencing Caregiver-Reported Autistic Trait Symptomatology in Toddlers

Current research on children's autistic traits in the general population relies predominantly on caregiver-report, yet the extent to which individual, caregiver or demographic characteristics are associated with informants' ratings has not been sufficiently explored. In this study, caregivers of 396 Singaporean two-year-olds from a birth cohort study completed the Quantitative Checklist for Autism in Toddlers. Children's gender, cognitive functioning and birth order, maternal age, and ethnic group membership were not significant predictors of caregiver-reported autistic traits. Poorer child language development and higher maternal depressive symptoms significantly predicted more social-communicative autistic traits, while lower maternal education predicted more behavioural autistic traits. Children's language and informants' educational level and depressive symptomatology may need to be considered in caregiver-reports of autistic traits.

Magnetoencephalography reveals an increased non-target P3a, but not target P3b, that is associated with high non-clinical psychosocial deficits

Auditory processing deficits are frequently identified in autism and schizophrenia, and the two disorders have been shown to share psychosocial difficulties. This study used magnetoencephalography to investigate auditory processing differences for those with a high degree of a non-clinical autistic and schizotypal trait phenotype, Social Disorganisation (SD). Participants were 18 low (9 female) and 19 high (9 female) SD scorers (18-40 years) who completed a three-stimulus auditory oddball paradigm of speech sounds (standard: 100ms 'o', deviant: 150ms 'o', novel: 150ms 'e'). Spatio-temporal cluster analysis revealed increased amplitude for the high SD group in a left (p = 0.006) and a right (p = 0.020) hemisphere cluster in response to the novel non-target. No cluster differences were found in response to the target deviant. These findings suggest that those with a high degree of the SD phenotype recruit more cortical resources when processing unattended, novel speech stimuli, which may lead to psychosocial deficits.

Empathizing and systemizing are differentially related to dimensions of autistic traits in the general population

Empathizing-Systemizing Theory suggests that low empathizing and high systemizing are linked to autistic traits in the general population. Evidence from autistic individuals is convincing, but more research in the normal population is needed. Method: We conducted two surveys (N = 3,345) investigating the relationships between empathizing, systemizing and autistic traits in the general population, using a large variety of self-report instruments and direct performance tests. Results: Strong connections between autistic symptoms, empathizing, and systemizing were found using commonly used measures (Autism Quotient, Systemizing Quotient and Empathizing Quotient). Other measures on empathizing and systemizing found the connections that E-S-theory predicts, but the correlations were a lot more modest. Weak empathizing was related to autism's social difficulties, while systemizing was linked to non-social aspects of autism. Conclusions: The present results support the main tenets of empathizing-systemizing theory, but suggest that earlier findings might be inflated due to overlapping items in the most common assessment instruments.