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

Neuropsychological investigation of "the amazing memory man"

OBJECTIVE

Mnemonists, memory champions, and persons with highly superior autobiographical memory (HSAM) are apparently rare breeds, with no more than a few dozen cases of each described in the neuroscientific literature. This report describes a newly discovered HSAM case who has extraordinary memory for a wider range of material than has heretofore been described.

METHOD

Subject MM was interviewed about his personal life and administered standard clinical tests of cognition and personality, as well as experimental tasks assessing personal and generic episodic and semantic memory. Finally, he was studied with high resolution structural MRI of the medial temporal lobes, as well as brain connectivity analysis using resting-state functional MRI.

RESULTS

MM's ability to recall general factual information, historical facts and dates, sports statistics, and popular culture, as well as personal life experiences, is exceptional, even though he performs in only the average range on tests of intellect and new learning ability. Unlike most mnemonists, he denies using any specific mnemonic strategy and, unlike many other HSAM cases, is unable to recall highly specific details of days in his adult life. Structural brain imaging in MM reveals atypical anatomy in his left temporal lobe, and functional neuroimaging suggests greater than usual connectivity of the left hippocampus with premotor, prefrontal and retrosplenial cingulate cortex.

CONCLUSIONS

These observations are discussed in the context of previous studies of mnemonists and HSAM cases, some of which implicate hyperconnectivity among components of an expanded memory network in extraordinary memory retrieval. (PsycINFO Database Record

A functional polymorphism of the OXTR gene is associated with autistic traits in Caucasian and Asian populations

There is increasing evidence for associations between polymorphisms of the oxytocin receptor (OXTR) gene and autism spectrum disorder, but to date no study has established links with autistic traits in healthy subjects and potential cultural differences. The present research firstly investigated associations between three widely studied OXTR SNPs and autistic and empathic traits (rs53576 (G/A); rs2254298 (G/A); rs2268498 (T/C)) in two independent studies on male and female Caucasian (n = 537) and Chinese students (n = 280). Autistic and empathic traits were measured in all subjects in the two independent groups using the Autism -Spectrum Quotient (AQ) and the Interpersonal Reactivity Index (IRI) respectively, together with their sub-scales. For both sites, genotyping of the OXTR SNPs was conducted on buccal swab samples using a Cobas Z 480 Light Cycler following automated DNA extraction. Associations at the genotype level with autism trait scores were found in Caucasian subjects for rs2268498 only, with TT carriers having the lowest AQ scores compared with those carrying at least one C-allele. This finding was independently replicated in the Chinese sample although a smaller proportion carried the C-allele compared with the Caucasian sample. Some minor associations were found between empathy trait scores and the three SNPs but were not consistent between the samples. These findings show for the first time that the rs2268498 SNP localized in the promoter flanking region of the OXTR gene is associated with autistic traits in different ethnic/cultural groups. This provides further support for the role of the OXTR gene in relation to autism.

Spontaneous mentalizing in neurotypicals scoring high versus low on symptomatology of autism spectrum disorder

Spontaneous mentalizing ability has been linked to symptoms severity in individuals with autism spectrum disorder (ASD). Here we investigated whether in neurotypicals, higher levels of ASD symptomatology could also be linked to lower levels of spontaneous mentalizing, by comparing neurotypicals scoring high with those scoring low on the short Autism Spectrum Quotient. Participants watched movies during which they, and another agent, formed beliefs about the location of an object. These beliefs could influence reaction times (RT) to that object in the outcome phase. We expected participants with more ASD symptoms to show less spontaneous mentalizing, as reflected by a smaller effect of the other agent's beliefs on RT patterns (the ToM index). In contrast, the effect of own beliefs on RTs, reflecting an egocentric bias, was expected to be larger in the high-scoring group. Results showed that groups differed in the effect of the agent's beliefs; the ToM index was highly significant in the low-scoring group, while being absent in the high-scoring group. No difference in egocentric bias was observed. These findings suggest that the relationship between levels of ASD symptomatology and spontaneous mentalizing is not only present in individuals with ASD, but also in the neurotypical population.

The specificity of the link between alexithymia, interoception, and imitation

Alexithymia is a subclinical condition traditionally characterized by difficulties identifying and describing one's own emotions. Recent formulations of alexithymia, however, suggest that the condition may result from a generalized impairment in the perception of all bodily signals ("interoception"). Interoceptive accuracy has been associated with a variety of deficits in social cognition, but recently with an improved ability to inhibit the automatic tendency to imitate the actions of others. The current study tested the consequences for social cognition of the hypothesized association between alexithymia and impaired interoception by examining the relationship between alexithymia and the ability to inhibit imitation. If alexithymia is best characterized as a general interoceptive impairment, then one would predict that alexithymia would have the same relationship with the ability to control imitation as does interoceptive accuracy. Forty-three healthy adults completed measures of alexithymia, imitation-inhibition, and as a control, inhibition of nonimitative spatial compatibility. Results revealed the predicted relationship, such that increasing alexithymia was associated with an improved ability to inhibit imitation, and that this relationship was specific to imitation-inhibition. These results support the characterization of alexithymia as a general interoceptive impairment and shed light on the social ability of alexithymic individuals-with implications for the multitude of psychiatric, neurological, and neurodevelopmental disorders associated with high rates of alexithymia. (PsycINFO Database Record

Gaze Following is Related to the Broader Autism Phenotype in a Sex-Specific Way: Building the Case for Distinct Male and Female Autism Phenotypes

The search for a female autism phenotype is difficult, given the low diagnostic rates in females. Here, we studied potential sex differences in a core feature of autism, difficulty with eye gaze processing, among typically developing individuals who vary in the broad autism phenotype, which includes autistic-like traits that are common, continuously distributed, and similarly heritable in males and females. Participants viewed complex images of an actor in a naturalistic scene looking at one of many possible objects and had to identify the target gazed-at object. Among males, those high in autistic-like traits exhibited worse eye gaze following performance than did those low in these traits. Among females, eye gaze following behavior did not vary with autistic-like traits. These results suggest that deficient eye gaze following behavior is part of the broader autism phenotype for males, but may not be a part of the female autism phenotype.

Are autistic traits associated with suicidality? A test of the interpersonal-psychological theory of suicide in a non-clinical young adult sample

Autism spectrum conditions (ASC) has recently been associated with increased risk of suicidality. However, no studies have explored how autistic traits may interact with current models of suicidal behavior in a non-clinical population. The current study therefore explored how self-reported autistic traits interact with perceived burdensomeness and thwarted belongingness in predicting suicidal behavior, in the context of the Interpersonal-Psychological Theory of Suicide (IPTS). 163 young adults (aged 18-30 years) completed an online survey including measures of thwarted belonging and perceived burdensomeness (Interpersonal Needs Questionnaire), self-reported autistic traits (Autism Spectrum Quotient), current depression (Centre for Epidemiological Studies Depression Scale), and lifetime suicidality (Suicide Behavior Questionnaire-Revised). Results showed that burdensomeness and thwarted belonging significantly mediated the relationship between autistic traits and suicidal behavior. Both depression and autistic traits significantly predicted thwarted belonging and perceived burdensomeness. Autistic traits did not significantly moderate the relationship between suicidal behavior and thwarted belonging or perceived burdensomeness. Results suggest that the IPTS provides a useful framework for understanding the influence of autistic traits on suicidal behavior. However, the psychometric properties of these measures need be explored in those with clinically confirmed diagnosis of ASC. Autism Res 2017, 10: 1891-1904. © 2017 The Authors Autism Research published by International Society for Autism Research and Wiley Periodicals, Inc.

LAY SUMMARY

Recent research has shown that people with high autistic traits are more likely to attempt suicide. However, no studies have explored why. We found that people with high autistic traits were more likely to experience feelings that they do not belong in the world, are a burden on others, and depression, which may increase their likelihood of attempting suicide. These results suggest that promoting inclusion and independence in those with high autistic traits could help prevent people attempting suicide.

Decreased reward value of biological motion among individuals with autistic traits

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The Social Motivation Theory of ASD links social impairments to reduced value of social stimuli.

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We evaluated the reward value of human motion among people with a range of AQ scores.

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Subjects value human motion more than robotic or control motion, but this preference diminishes with higher AQ scores.

The Social Motivation Theory posits that a reduced sensitivity to the value of social stimuli, specifically faces, can account for social impairments in Autism Spectrum Disorders (ASD). Research has demonstrated that typically developing (TD) individuals preferentially orient towards another type of salient social stimulus, namely biological motion. Individuals with ASD, however, do not show this preference. While the reward value of faces to both TD and ASD individuals has been well-established, the extent to which individuals from these populations also find human motion to be rewarding remains poorly understood. The present study investigated the value assigned to biological motion by TD participants in an effort task, and further examined whether these values differed among individuals with more autistic traits. The results suggest that TD participants value natural human motion more than rigid, machine-like motion or non-human control motion, but this preference is attenuated among individuals reporting more autistic traits. This study provides the first evidence to suggest that individuals with more autistic traits find a broader conceptualisation of social stimuli less rewarding compared to individuals with fewer autistic traits. By quantifying the social reward value of human motion, the present findings contribute an important piece to our understanding of social motivation in individuals with and without social impairments.

Size Constancy is Preserved but Afterimages are Prolonged in Typical Individuals with Higher Degrees of Self-Reported Autistic Traits

Deficits in perceptual constancies from early infancy have been proposed to contribute to autism and exacerbate its symptoms (Hellendoorn et al., Frontiers in Psychology 6:1–16, 2015). Here, we examined size constancy in adults from the general population (N = 106) with different levels of self-reported autistic traits using an approach based on negative afterimages. The afterimage strength, as indexed by duration and vividness, was also quantified. In opposition to the Hellendoorn and colleagues’ model, we were unable to demonstrate any kind of relationship between abilities in size constancy and autistic traits. However, our results demonstrated that individuals with higher degrees of autistic traits experienced more persistent afterimages. We discuss possible retinal and post-retinal explanations for prolonged afterimages in people with higher levels of autistic traits.

Gray Matter Characteristics in Mid and Old Aged Adults with ASD

It is widely acknowledged that the brain anatomy of children and adolescents with autism spectrum disorder (ASD) shows a different developmental pattern then typical age-matched peers. There is however, a paucity of studies examining gray matter in mid and late adulthood in ASD. In this cross-sectional neuroimaging study, we, performed vertex-wise whole-brain and region-of-interest analyses of cortical volume, thickness, surface area, and gyrification index in 51 adults with and 49 without ASD, between 30 and 75 years. There was significant age-related volume loss and cortical thinning, but there were no group differences. The lack of significant anatomical differences between intellectual able individuals with and without ASD, suggests that ASD is not (strongly) related to gray matter morphology in mid and late adulthood.

Insensitivity to Fearful Emotion for Early ERP Components in High Autistic Tendency Is Associated with Lower Magnocellular Efficiency

Low spatial frequency (LSF) visual information is extracted rapidly from fearful faces, suggesting magnocellular involvement. Autistic phenotypes demonstrate altered magnocellular processing, which we propose contributes to a decreased P100 evoked response to LSF fearful faces. Here, we investigated whether rapid processing of fearful facial expressions differs for groups of neurotypical adults with low and high scores on the Autistic Spectrum Quotient (AQ). We created hybrid face stimuli with low and high spatial frequency filtered, fearful, and neutral expressions. Fearful faces produced higher amplitude P100 responses than neutral faces in the low AQ group, particularly when the hybrid face contained a LSF fearful expression. By contrast, there was no effect of fearful expression on P100 amplitude in the high AQ group. Consistent with evidence linking magnocellular differences with autistic personality traits, our non-linear VEP results showed that the high AQ group had higher amplitude K2.1 responses than the low AQ group, which is indicative of less efficient magnocellular recovery. Our results suggest that magnocellular LSF processing of a human face may be the initial visual cue used to rapidly and automatically detect fear, but that this cue functions atypically in those with high autistic tendency.

The Latent Structure of Autistic Traits: A Taxometric, Latent Class and Latent Profile Analysis of the Adult Autism Spectrum Quotient

Autistic traits are widely thought to operate along a continuum. A taxometric analysis of Adult Autism Spectrum Quotient data was conducted to test this assumption, finding little support but identifying a high severity taxon. To understand this further, latent class and latent profile models were estimated that indicated the presence of six distinct subtypes: one with little probability of endorsing any autistic traits, one engaging in ‘systemising’ behaviours, three groups endorsing multiple components of Wing and Gould’s autistic triad, and a group similar in size and profile to the taxon previously identified. These analyses suggest the AQ (and potentially by extension autistic traits) have a categorical structure. These findings have important implications for the analysis and interpretation of AQ data.

Brief Report: Personality Mediates the Relationship between Autism Quotient and Well-Being: A Conceptual Replication using Self-Report

Autism spectrum disorder (ASD) impacts well-being across the lifespan. Individuals with ASD evidence differences in personality traits and self-concept clarity that are predictors of well-being in typically-developing individuals. The current research replicates a growing body of evidence demonstrating differences in well-being and personality between individuals low in ASD characteristics (n = 207) and individuals high in ASD characteristics (n = 46) collected from the general population using an online survey. Results were consistent in a subsample of demographically matched pairs (n = 39 per group) and relative to norms. Further, the current research provides the first evidence that openness, conscientiousness, emotional stability, and self-concept clarity mediate the relationship between ASD characteristics and well-being.

Embedded Figures Test Performance in the Broader Autism Phenotype: A Meta-analysis

People with autism show superior performance to controls on the Embedded Figures Test (EFT). However, studies examining the relationship between autistic-like traits and EFT performance in neurotypical individuals have yielded inconsistent findings. To examine the inconsistency, a meta-analysis was conducted of studies that (a) compared high and low Autism-Spectrum Quotient (AQ) groups, and (b) treated AQ as a continuous variable. Outcomes are consistent with superior visual search forming part of the broader autism phenotype, but in existing literature, this is evident only when comparing extreme groups. Reanalysis of data from previous studies suggests findings are unlikely to be driven by a small number of high scorers. Monte Carlo simulations are used to illustrate the effect of methodological differences on results.

The Relationship Between Autistic Traits and Atypical Sensory Functioning in Neurotypical and ASD Adults: A Spectrum Approach

Sensory processing atypicalities are a common feature in Autism Spectrum Disorders (ASD) and have previously been linked to a range of behaviours in individuals with ASD and atypical neurological development. More recently research has demonstrated a relationship between autistic traits in the neurotypical (NT) population and increased levels of atypical sensory behaviours. The aim of the present study is to extend previous research by examining specific patterns across aspects of autistic traits and sensory behaviours within both ASD and NT populations. The present study recruited 580 NT adults and 42 high-functioning ASD adults with a confirmed diagnosis to investigate the relationship between specific aspects of autistic traits and sensory processing using the subscales of the autism spectrum quotient (AQ) and adult/adolescent sensory profile (AASP). Results showed a significant relationship between all subscales except for attention to detail and imagination on the AQ and provided the first evidence that the strength and pattern of this relationship is identical between NT and ASD adults. These data also provided support for the broader autism phenotype, uncovering a clear progression of sensory atypicalities in line with an increase in autistic traits, regardless of diagnostic status, which has potential implications for the spectrum approach to ASD and how sensory behaviours across the whole of the neurotypical population are conceptualised.

The overlap between autistic spectrum conditions and borderline personality disorder

BACKGROUND

Both people with autism spectrum conditions (ASC) and borderline personality disorder (BPD) are significantly challenged in terms of understanding and responding to emotions and in interpersonal functioning.

AIMS

To compare ASC, BPD, and comorbid patients in terms of autistic traits, empathy, and systemizing.

METHODS

624 ASC, 23 BPD, and 16 comorbid (ASC+BPD) patients, and 2,081 neurotypical controls (NC) filled in the Autism Spectrum Quotient (AQ), the Empathy Quotient (EQ) and the Systemizing Quotient-Revised (SQ-R).

RESULTS

On the AQ, the comorbid group scored higher than the ASC group, who in turn scored higher than the BPD group, who scored higher than controls. On the EQ, we found the comorbid and ASC groups scored lower than the BPD group, who were not different from controls. Finally, on the SQ-R, we found the ASC and BPD group both scored higher than controls.

CONCLUSIONS

Similar to ASC, BPD patients have elevated autistic traits and a strong drive to systemize, suggesting an overlap between BPD and ASC.

Adults with autism overestimate the volatility of the sensory environment

Insistence on sameness and intolerance of change are among the diagnostic criteria for autism spectrum disorder (ASD), but little research has addressed how people with ASD represent and respond to environmental change. Here, behavioral and pupillometric measurements indicated that adults with ASD are less surprised than neurotypical adults when their expectations are violated, and decreased surprise is predictive of greater symptom severity. A hierarchical Bayesian model of learning suggested that in ASD, a tendency to overlearn about volatility in the face of environmental change drives a corresponding reduction in learning about probabilistically aberrant events, thus putatively rendering these events less surprising. Participant-specific modeled estimates of surprise about environmental conditions were linked to pupil size in the ASD group, thus suggesting heightened noradrenergic responsivity in line with compromised neural gain. This study offers insights into the behavioral, algorithmic and physiological mechanisms underlying responses to environmental volatility in ASD.

Hooked on a feeling: Repetitive cognition and internalizing symptomatology in relation to autism spectrum symptomatology

Repetitive cognition, including rumination such as that seen in depression, has been shown to correlate with depression symptoms in both typically developing individuals and individuals with autism spectrum disorder. Repetitive cognition is more common in autism spectrum disorder than in typically developing peers, as is depression; thus, this study evaluated the role of repetitive cognition in relation between autism spectrum symptomatology and depressive symptomatology. In all, 200 typically developing adults completed self-report questionnaires measuring autism spectrum symptomatology, different forms of repetitive cognition (general perseveration and depressive rumination), depression, and rejection sensitivity. Perseveration was found to mediate the relation between autism spectrum symptoms and depression, and to partially mediate the relation between autism spectrum symptoms and rejection sensitivity. We conclude that it is of vital importance to consider cognition when considering depression in autism spectrum disorder.

Neural Response to Biological Motion in Healthy Adults Varies as a Function of Autistic-Like Traits

Perception of biological motion is an important social cognitive ability that has been mapped to specialized brain regions. Perceptual deficits and neural differences during biological motion perception have previously been associated with autism, a disorder classified by social and communication difficulties and repetitive and restricted interests and behaviors. However, the traits associated with autism are not limited to diagnostic categories, but are normally distributed within the general population and show the same patterns of heritability across the continuum. In the current study, we investigate whether self-reported autistic-like traits in healthy adults are associated with variable neural response during passive viewing of biological motion displays. Results show that more autistic-like traits, particularly those associated with the communication domain, are associated with increased neural response in key regions involved in social cognitive processes, including prefrontal and left temporal cortices. This distinct pattern of activation might reflect differential neurodevelopmental processes for individuals with varying autistic-like traits, and highlights the importance of considering the full trait continuum in future work.

Differential responses of the dorsomedial prefrontal cortex and right posterior superior temporal sulcus to spontaneous mentalizing

Previous research suggests a role of the dorsomedial prefrontal cortex (dmPFC) in metacognitive representation of social information, while the right posterior superior temporal sulcus (pSTS) has been linked to social perception. This study targeted these functional roles in the context of spontaneous mentalizing. An animated shapes task was presented to 46 subjects during functional magnetic resonance imaging. Stimuli consisted of video clips depicting animated shapes whose movement patterns prompt spontaneous mentalizing or simple intention attribution. Based on their differential response during spontaneous mentalizing, both regions were characterized with respect to their task-dependent connectivity profiles and their associations with autistic traits. Functional network analyses revealed highly localized coupling of the right pSTS with visual areas in the lateral occipital cortex, while the dmPFC showed extensive coupling with instances of large-scale control networks and temporal areas including the right pSTS. Autistic traits were related to mentalizing-specific activation of the dmPFC and to the strength of connectivity between the dmPFC and posterior temporal regions. These results are in good agreement with the hypothesized roles of the dmPFC and right pSTS for metacognitive representation and perception-based processing of social information, respectively, and further inform their implication in social behavior linked to autism. Hum Brain Mapp 38:3791-3803, 2017. © 2017 Wiley Periodicals, Inc.

Delusion-proneness displays comorbidity with traits of autistic-spectrum disorders and ADHD

There is an increasing body of evidence suggesting a significant comorbidity between psychotic disorders such as schizophrenia and attention-deficit/hyperactivity disorder (ADHD) or autism-spectrum disorders (ASD). Recently, research on psychosis-proneness in otherwise healthy individuals has been a promising way to better understand the mechanisms underlying psychosis. As both ADHD and ASD symptoms show a normal distribution in the general population, such trait comorbidity may confound studies on psychosis-proneness. Thus, understanding the extent to which psychosis-proneness relates to ADHD and ASD symptoms in healthy subjects is crucial for studies focusing on at-risk or psychosis-prone populations. In the present paper we tested the robustness of overlap between psychosis-proneness and ADHD/ASD symptoms, by studying correlations between the scores of three commonly-used questionnaires assessing delusion-proneness (Peters’ Delusion Inventory), ADHD tendencies (Adult ADHD Self-Report Scale) and ASD tendencies (Autism Quotient), on a large sample of healthy individuals (n = 925) using raw scores, prototypical questions and a factor analysis. The results showed consistently positive correlations between psychosis-proneness and ADHD-, as well as ASD-symptoms. While the effect was weak for ASD, it was moderate for ADHD. The findings support the idea that when investigating psychosis-proneness it is crucial to also take ADHD- and ASD-tendencies into account, in order to conclude that the reported results in a given study are specific to psychosis-proneness. The observed trait correlations also suggest a common pathway in the underlying information processing of these states.

Autistic Traits are Linked to Individual Differences in Familiar Voice Identification

Autistic traits vary across the general population, and are linked with face recognition ability. Here we investigated potential links between autistic traits and voice recognition ability for personally familiar voices in a group of 30 listeners (15 female, 16-19 years) from the same local school. Autistic traits (particularly those related to communication and social interaction) were negatively correlated with voice recognition, such that more autistic traits were associated with fewer familiar voices identified and less ability to discriminate familiar from unfamiliar voices. In addition, our results suggest enhanced accessibility of personal semantic information in women compared to men. Overall, this study establishes a detailed pattern of relationships between voice identification performance and autistic traits in the general population.

Etiological influences on the stability of autistic traits from childhood to early adulthood: evidence from a twin study

BACKGROUND

Autism spectrum disorders (ASD) are persistent and lifelong conditions. Despite this, almost all twin studies focus on childhood. This twin study investigated the stability of autistic traits from childhood to early adulthood and explored the degree to which any stability could be explained by genetic or environmental factors.

METHODS

Parents of over 2500 twin pairs completed questionnaires assessing autistic traits when twins were aged either 9 or 12 years and again when twins were aged 18. Bivariate twin analysis assessed the degree of phenotypic and etiological stability in autistic traits across this period. Genetic overlap in autistic traits across development was also tested in individuals displaying a broad ASD phenotype, defined as scoring within the highest 5% of the sample.

RESULTS

Autistic traits displayed moderate phenotypic stability (r = .39). The heritability of autistic traits was 76-77% in childhood and 60-62% in adulthood. A moderate degree of genetic influences on childhood autistic traits were carried across into adulthood (genetic correlation = .49). The majority (85%) of the stability in autistic traits was attributable to genetic factors. Genetic influences on autistic traits were moderately stable from childhood to early adulthood at the extremes (genetic correlation = .64).

CONCLUSIONS

Broad autistic traits display moderate phenotypic and etiological stability from childhood to early adulthood. Genetic factors accounted for almost all phenotypic stability, although there was some phenotypic and etiological instability in autistic traits. Thus, autistic traits in adulthood are influenced by a combination of enduring and unique genetic factors.

Divergence of Age-Related Differences in Social-Communication: Improvements for Typically Developing Youth but Declines for Youth with Autism Spectrum Disorder

Although social-communication difficulties and repetitive behaviors are hallmark features of autism spectrum disorder (ASD) and persist across the lifespan, very few studies have compared age-related differences in these behaviors between youth with ASD and same-age typically developing (TD) peers. We examined this issue using SRS-2 (Social Responsiveness Scale-Second Edition) measures of social-communicative functioning and repetitive behaviors in a stratified cross-sectional sample of 324 youth with ASD in the absence of intellectual disability, and 438 TD youth (aged 4-29 years). An age-by-group interaction emerged indicating that TD youth exhibited age-related improvements in social-communication scores while the ASD group demonstrated age-related declines in these scores. This suggests that adolescents/adults with ASD may fall increasingly behind their same-age peers in social-communicative skills.

The Influence of Prior Knowledge on Perception and Action: Relationships to Autistic Traits

Autism is characterised by a range of perceptual and sensorimotor deficits, which might be related to abnormalities in how autistic individuals use prior knowledge. We investigated this proposition in a large non-clinical population in the context of the size-weight illusion, where individual’s expectations about object weight influence their perceptions of heaviness and fingertip forces. Although there was no relationship between autistic traits and the magnitude of the illusion, we observed an inverse relationship between AQ scores and how expectations influenced initial fingertip force application. These findings provide a novel dissociation between how perceptual and sensorimotor processes are related to autistic traits, and suggest that, autistic traits might explain some of the variance surrounding how individuals grip and lift objects.

Dyspraxia and autistic traits in adults with and without autism spectrum conditions

BACKGROUND

Autism spectrum conditions (ASC) are frequently associated with motor coordination difficulties. However, no studies have explored the prevalence of dyspraxia in a large sample of individuals with and without ASC or associations between dyspraxia and autistic traits in these individuals.

METHODS

Two thousand eight hundred seventy-one adults (with ASC) and 10,706 controls (without ASC) self-reported whether they have been diagnosed with dyspraxia. A subsample of participants then completed the Autism Spectrum Quotient (AQ; 1237 ASC and 6765 controls) and the Empathy Quotient (EQ; 1147 ASC and 6129 controls) online through the Autism Research Centre website. The prevalence of dyspraxia was compared between those with and without ASC. AQ and EQ scores were compared across the four groups: (1) adults with ASC with dyspraxia, (2) adults with ASC without dyspraxia, (3) controls with dyspraxia, and (4) controls without dyspraxia.

RESULTS

Adults with ASC were significantly more likely to report a diagnosis of dyspraxia (6.9%) than those without ASC (0.8%). In the ASC group, those with co-morbid diagnosis of dyspraxia did not have significantly different AQ or EQ scores than those without co-morbid dyspraxia. However, in the control group (without ASC), those with dyspraxia had significantly higher AQ and lower EQ scores than those without dyspraxia.

CONCLUSIONS

Dyspraxia is significantly more prevalent in adults with ASC compared to controls, confirming reports that motor coordination difficulties are significantly more common in this group. Interestingly, in the general population, dyspraxia was associated with significantly higher autistic traits and lower empathy. These results suggest that motor coordination skills are important for effective social skills and empathy.

Association testing of vasopressin receptor 1a microsatellite polymorphisms in non-clinical autism spectrum phenotypes

Variation in the AVPR1a gene, which codes for a receptor for the neurohormone vasopressin, has been found to relate to autism risk. Interestingly, variation in this gene also relates to differences in social behaviour in non-clinical populations. Variation in this gene may affect expression of AVPR1a receptors in brain areas involved in social behaviour. Here, we tested whether AVPR1a variation was associated with Autism Quotient (AQ) scores, a questionnaire that measures non-clinical manifestations of autism, in a population of 873 healthy university students. The AVPR1a RS1 and RS3 microsatellites were examined, and variants were categorized as "long" or "short". The RS3 long/long genotype was significantly associated with a higher AQ score (i.e., a more autistic-like phenotype) for the combined population and for females only. Further examination showed that this relationship was due to a specific RS3 variant, termed the "target allele", which previous research has linked to reduced altruism and increased marital problems in healthy individuals. We also observed that the relationship between RS3 genotype and AQ score was mainly due to the "attention switching" (the ability to shift attention from one task to another) component of the questionnaire; this ability is commonly impaired in autism spectrum disorders. Overall, our study establishes continuity between the existing AVPR1a research in clinical and non-clinical populations. Our results suggest that vasopressin may exert its effects on social behaviour in part by modulating attentional focus between social and non-social cues. Autism Res 2017, 10: 750-756. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

Exploring sex differences in autistic traits: A factor analytic study of adults with autism

Research has highlighted potential differences in the phenotypic and clinical presentation of autism spectrum conditions across sex. Furthermore, the measures utilised to evaluate autism spectrum conditions may be biased towards the male autism phenotype. It is important to determine whether these instruments measure the autism phenotype consistently in autistic men and women. This study evaluated the factor structure of the Autism Spectrum Quotient Short Form in a large sample of autistic adults. It also systematically explored specific sex differences at the item level, to determine whether the scale assesses the autism phenotype equivalently across males and females. Factor analyses were conducted among 265 males and 285 females. A two-factor structure consisting of a social behaviour and numbers and patterns factor was consistent across groups, indicating that the latent autism phenotype is similar among both autistic men and women. Subtle differences were observed on two social behaviour item thresholds of the Autism Spectrum Quotient Short Form, with women reporting scores more in line with the scores expected in autism on these items than men. However, these differences were not substantial. This study showed that the Autism Spectrum Quotient Short Form detects autistic traits equivalently in males and females and is not biased towards the male autism phenotype.

Do We Need Multiple Informants When Assessing Autistic Traits? The Degree of Report Bias on Offspring, Self, and Spouse Ratings

This study focused on the degree of report bias in assessing autistic traits. Both parents of 124 preschoolers completed the Social Communication Questionnaire and the Autism-spectrum Quotient. Acceptable agreement existed between mother and father reports of children’s mean scores of autistic traits, but interrater reliability for rank-order correlations was only fair. No evidence was found for report bias regarding parent-offspring autistic traits. However, adult autistic ratings were strongly biased: spouse-ratings were higher than self-ratings, correlations were only fair when both parents reported about the same person, and resemblance was higher for reports from the same person than for spouses’ separate self-reports. It is advisable to involve multiple informants when assessing autistic traits, and to use procedural and/or statistical remedies to control for report bias.

Age-related differences in autism: The case of white matter microstructure

Autism spectrum disorder (ASD) is typified as a brain connectivity disorder in which white matter abnormalities are already present early on in life. However, it is unknown if and to which extent these abnormalities are hard-wired in (older) adults with ASD and how this interacts with age-related white matter changes as observed in typical aging. The aim of this first cross-sectional study in mid- and late-aged adults with ASD was to characterize white matter microstructure and its relationship with age. We utilized diffusion tensor imaging with head motion control in 48 adults with ASD and 48 age-matched controls (30-74 years), who also completed a Flanker task. Intra-individual variability of reaction times (IIVRT) measures based on performance on the Flanker interference task were used to assess IIVRT-white matter microstructure associations. We observed primarily higher mean and radial diffusivity in white matter microstructure in ASD, particularly in long-range fibers, which persisted after taking head motion into account. Importantly, group-by-age interactions revealed higher age-related mean and radial diffusivity in ASD, in projection and association fiber tracts. Subtle dissociations were observed in IIVRT-white matter microstructure relations between groups, with the IIVRT-white matter association pattern in ASD resembling observations in cognitive aging. The observed white matter microstructure differences are lending support to the structural underconnectivity hypothesis in ASD. These reductions seem to have behavioral percussions given the atypical relationship with IIVRT. Taken together, the current results may indicate different age-related patterns of white matter microstructure in adults with ASD. Hum Brain Mapp 38:82-96, 2017. © 2016 Wiley Periodicals, Inc.

Mirror-Touch Synaesthesia Is Not Associated with Heightened Empathy, and Can Occur with Autism

Research has linked Mirror-Touch (MT) synaesthesia with enhanced empathy. We test the largest sample of MT synaesthetes to date to examine two claims that have been previously made: that MT synaesthetes (1) have superior empathy; and (2) only ever experience their MT synaesthesia in response to viewing a person being touched. Given that autism has been suggested to involve deficits in cognitive empathy, we also test two predictions: that MT synaesthetes should (3) be less likely than general population individuals without MT synaesthesia to have an autism spectrum condition (ASC), if MT is characterized by superior empathy; and (4) have fewer autistic traits. We selected three groups: a pure MT synaesthesia group (N = 46), a pure grapheme-colour (GC) synaesthesia group (N = 36), and a typical control group without synaesthesia (N = 46). Participants took three measures of empathy and one measure of autistic traits. MT synaesthetes did not show enhanced empathy. In addition, 30% of all MT synaesthetes recruited into this study (N = 135) reported also having ASC, and MT synaesthetes showed higher autistic trait scores than controls. Finally, some MT experiences were reported in response to viewing objects being touched. Our findings dispute the views that MT synaesthesia is linked with enhanced empathy, is less likely to occur with ASC or elevated autistic traits, and is specific to seeing a person being touched.

How useful are the Adult Asperger Assessment and AQ-10 within an adult clinical population of all intellectual abilities?

Purpose

– The Adult Asperger Assessment (AAA) was designed to be a screening tool to identify adults with Asperger syndrome and/or high-functioning autism. The AAA includes three questionnaires; the Autism Quotient (AQ), the Empathy Quotient (EQ) and the Relatives Questionnaire (RQ). The Autism Quotient-10 (AQ-10) was designed to be a “red flag” for healthcare professionals considering referral for ASD assessment. The purpose of this paper is to determine the usefulness of the AAA and AQ-10 as part of an adult autism diagnostic pathway that includes patients of all intellectual ability.

Design/methodology/approach

– Results were obtained for all patients who had received a clinical decision at Leeds Autism Diagnostic Service, which is a service that assesses patients of all intellectual ability, during 2015, n=214. Of these 132 were included in the analysis, 77 patients were excluded for not completing the AAA and four were excluded for not receiving a clinical decision.

Findings

– Results suggest that patients diagnosed with ASD without intellectual disabilities score on average 35 on the AQ, 17 on the EQ and 20 on the RQ. Those not diagnosed with ASD score on average 33 on the AQ, 22 on the EQ and 15 on the RQ. Patients with intellectual disabilities, scores are lower on the AQ, and higher on the EQ and RQ than those without intellectual disabilities. These results are the same regardless of diagnosis of ASD. The RQ is the only questionnaire to result in a significant difference between those diagnosed and not diagnosed. Results suggest that the AQ-10 is not useful in this clinical population.

Research limitations/implications

– This study was undertaken as part of a service development improvement process. The specific demographics of this clinical population may have influenced the findings. The process will need to be repeated to ensure that the results are consistent across time and increased sample size. The population of patients with an intellectual disability is small, further studies into the use of the AAA or the design of other intellectual disability specific screening tools should be pursued. It is of note that the AAA was never intended for use within an intellectual disability population.

Originality/value

– This is an original paper as it will be the first to consider the usefulness of each of the aspects of the AAA collectively. It will be the first to assess: the AQ-10 alongside the AAA, the usefulness of the AAA regardless of intellectual ability and the usefulness of the AAA within a clinical population by using the diagnostic outcome as the benchmark of the usefulness of the AAA scores. This paper will only be discussing the scores generated by the AAA, and the correlation of these scores with a diagnosis.

Broad autism spectrum and obsessive-compulsive symptoms in adults with the fragile X premutation

OBJECTIVE

Clinical observations and a limited number of research studies provide evidence that the fragile X premutation may confer risk for autism, executive dysfunction, and psychopathology. The link to autism spectrum symptoms and social cognition deficits with the premutation remains uncertain, and thus was the focus of the present investigation.

METHOD

Our sample included 131 individuals, 42 men/22 women with the FMR1 premutation (mean age = 31.83 ± 8.59 years) with a normal neurological exam, and 48 men/19 women healthy age-matched controls (mean age = 29.48 ± 7.29 years). Individuals completed a comprehensive neuropsychological battery with additional assessments for social cognition, broad autism spectrum, and obsessive-compulsive (OC) symptoms.

RESULTS

Premutation carriers self-reported higher rates of autism-related symptoms (Autism Quotient; p = .001). Among males only, premutation carriers showed more atypical social interaction (p < .001) and stereotyped behavior (p = .014) during standardized clinical examination on the Autism Diagnostic Observation Schedule (ADOS) relative to controls. Female premutation carriers reported significantly higher rates of OC symptoms compared to control females (p = .012). Molecular measures defining the expanded premutation (FMR1 CGG repeat length and/or mRNA) were significantly associated with a measure of theory of mind (Reading the Mind in the Eyes Task).

CONCLUSIONS

The results of this study indicate a higher rate of broad autism spectrum symptoms in some males with the premutation and provide evidence for an obsessive-compulsive subtype in female premutation carriers.

The Autism-Spectrum Quotient in Siblings of People With Autism

This study measures the distribution of autistic traits, using the autism-spectrum quotient (AQ), in siblings of individuals with autism spectrum conditions (ASC). Total AQ scores, along with AQ subscales, were collected from child, adolescent and adult controls, siblings, and volunteers with ASC using one of the three age-appropriate versions of the instrument: the AQ (adult self-report), the AQ-adolescent and AQ-child (both parent-reports). We examined the effect of Group (case, sibling and control) and AQ version (adult, adolescent and adult) on total and subscale scores. In addition, we tested for sex differences in all groups and on all versions. We found that in male and female adults, AQ scores in siblings fell between cases and controls (cases > siblings > controls). In children and adolescents, female siblings also scored higher than control females (female cases > female siblings > female controls), but there was no difference between male siblings and controls (male cases > male siblings = male controls). An investigation of subscale scores revealed that male siblings only differed from controls on the "Communication" subscale (male cases > male siblings > male controls), while female siblings differed from controls on all subscales except "Imagination" (female cases > female siblings > female controls). This study confirms the broader autism phenotype in siblings, and reveals this is modulated by sex and AQ version. Autism Res 2017, 10: 289-297. © 2016 The Authors Autism Research published by Wiley Periodicals, Inc. on behalf of International Society for Autism Research.

Systemizers Are Better Code-Breakers: Self-Reported Systemizing Predicts Code-Breaking Performance in Expert Hackers and Naïve Participants

Studies on hacking have typically focused on motivational aspects and general personality traits of the individuals who engage in hacking; little systematic research has been conducted on predispositions that may be associated not only with the choice to pursue a hacking career but also with performance in either naïve or expert populations. Here, we test the hypotheses that two traits that are typically enhanced in autism spectrum disorders—attention to detail and systemizing—may be positively related to both the choice of pursuing a career in information security and skilled performance in a prototypical hacking task (i.e., crypto-analysis or code-breaking). A group of naïve participants and of ethical hackers completed the Autism Spectrum Quotient, including an attention to detail scale, and the Systemizing Quotient (Baron-Cohen et al., 2001, 2003). They were also tested with behavioral tasks involving code-breaking and a control task involving security X-ray image interpretation. Hackers reported significantly higher systemizing and attention to detail than non-hackers. We found a positive relation between self-reported systemizing (but not attention to detail) and code-breaking skills in both hackers and non-hackers, whereas attention to detail (but not systemizing) was related with performance in the X-ray screening task in both groups, as previously reported with naïve participants (Rusconi et al., 2015). We discuss the theoretical and translational implications of our findings.

Reasoning on the Autism Spectrum: A Dual Process Theory Account

Dual process theory proposes two distinct reasoning processes in humans, an intuitive style that is rapid and automatic and a deliberative style that is more effortful. However, no study to date has specifically examined these reasoning styles in relation to the autism spectrum. The present studies investigated deliberative and intuitive reasoning profiles in: (1) a non-clinical sample from the general population with varying degrees of autism traits (n = 95), and (2) males diagnosed with ASD (n = 17) versus comparisons (n = 18). Taken together, the results suggest reasoning on the autism spectrum is compatible with the processes proposed by Dual Process Theory and that higher autism traits and ASD are characterised by a consistent bias towards deliberative reasoning (and potentially away from intuition).

Hedonic Capacity in the Broader Autism Phenotype: Should Social Anhedonia Be Considered a Characteristic Feature?

Impairments in social motivational processes may partially explain the differences in social interaction seen among individuals with autism spectrum disorder (ASD). The social motivation hypothesis would predict an association between reduced hedonic capacity and ASD. However, to date, findings have been mixed regarding hedonic deficits among individuals with ASD; adults report lower levels of both social and physical pleasure whereas adolescents only report experiencing lower social pleasure. Moreover, very few studies examining the association between anhedonia and autistic traits have used measures of hedonic response or taken temporal aspects of pleasure into account. The present study examined associations between autistic traits and the experience of pleasure using a non-clinical sample of young adults to further clarify the nature of hedonic deficits in the broader autism phenotype (BAP). Results revealed that autistic traits were negatively associated with both the experience of social pleasure as well as general pleasure, although the association was stronger for social pleasure. Regression analyses revealed that reduced social pleasure was a better predictor of autistic traits than general pleasure. Together these findings suggest that reduced social hedonic capacity is associated with autistic traits in the general population and should be included in conceptualizations of the BAP.

Intact priors for gaze direction in adults with high-functioning autism spectrum conditions

BACKGROUND

Autism Spectrum Conditions (ASC) are associated with a range of perceptual atypicalities, including abnormalities in gaze processing. Pellicano and Burr (Trends Cogn Sci 16(10):504-10, 2012) have argued that these atypicalities might be explained within a Bayesian framework, in which perception represents the combination of sensory information with prior knowledge. They propose that the Bayesian priors of individuals with ASC might be attenuated, such that their perception is less reliant on prior knowledge than neurotypical individuals. An important tenet of Bayesian decision theory is that increased uncertainty about incoming sensory information will lead to a greater influence of the prior on perception. Consistent with this, Mareschal et al. (Curr Biol 23(8):717-21, 2013) showed that when noise is added to the eyes of a face (increasing uncertainty about gaze direction), gaze is more likely to be perceived as direct.

METHODS

We adopted the same paradigm as Mareschal et al. to determine whether the influence of a prior on gaze perception is reduced in neurotypical participants with high numbers of autistic traits (experiment 1) and in individuals with a clinical diagnosis of ASC (experiment 2). Participants were presented with synthetic faces and asked to make a judgement about the relative gaze directions of the faces. Uncertainty about gaze direction was manipulated by adding noise to the eyes of a face.

RESULTS

Consistent with previous work, in both experiment 1 and experiment 2, participants showed a bias towards perceiving gaze as direct under conditions of uncertainty. However, there was no evidence that the magnitude of this bias was reduced either in the ASC group or in neurotypical controls with a high number of autistic traits.

CONCLUSIONS

Our findings challenge the attenuated priors theory of perception in ASC (Trends Cogn Sci 16(10):504-10, 2012) and related proposals (Trends Cogn Sci 17(1):1, 2013, Front Hum Neurosci 8:302, 2014), and suggest priors for gaze direction are intact in high-functioning ASC.

Alexithymia, not autism, is associated with impaired interoception

It has been proposed that Autism Spectrum Disorder (ASD) is associated with difficulties perceiving the internal state of one's body (i.e., impaired interoception), causing the socio-emotional deficits which are a diagnostic feature of the condition. However, research indicates that alexithymia - characterized by difficulties in recognizing emotions from internal bodily sensations - is also linked to atypical interoception. Elevated rates of alexithymia in the autistic population have been shown to underpin several socio-emotional impairments thought to be symptomatic of ASD, raising the possibility that interoceptive difficulties in ASD are also due to co-occurring alexithymia. Following this line of inquiry, the present study examined the relative impact of alexithymia and autism on interoceptive accuracy (IA). Across two experiments, it was found that alexithymia, not autism, was associated with atypical interoception. Results indicate that interoceptive impairments should not be considered a feature of ASD, but instead due to co-occurring alexithymia.

Theory of mind for processing unexpected events across contexts

Theory of mind, or mental state reasoning, may be particularly useful for making sense of unexpected events. Here, we investigated unexpected behavior across both social and non-social contexts in order to characterize the precise role of theory of mind in processing unexpected events. We used functional magnetic resonance imaging to examine how people respond to unexpected outcomes when initial expectations were based on (i) an object's prior behavior, (ii) an agent's prior behavior and (iii) an agent's mental states. Consistent with prior work, brain regions for theory of mind were preferentially recruited when people first formed expectations about social agents vs non-social objects. Critically, unexpected vs expected outcomes elicited greater activity in dorsomedial prefrontal cortex, which also discriminated in its spatial pattern of activity between unexpected and expected outcomes for social events. In contrast, social vs non-social events elicited greater activity in precuneus across both expected and unexpected outcomes. Finally, given prior information about an agent's behavior, unexpected vs expected outcomes elicited an especially robust response in right temporoparietal junction, and the magnitude of this difference across participants correlated negatively with autistic-like traits. Together, these findings illuminate the distinct contributions of brain regions for theory of mind for processing unexpected events across contexts.

A Comprehensive Review of the (1)H-MRS Metabolite Spectrum in Autism Spectrum Disorder

Neuroimaging studies of neuropsychiatric behavior biomarkers across spectrum disorders are typically based on diagnosis, thus failing to account for the heterogeneity of multi-dimensional spectrum disorders such as autism (ASD). Control group trait phenotypes are also seldom reported. Proton magnetic resonance spectroscopy (¹H-MRS) measures the abundance of neurochemicals such as neurotransmitters and metabolites and hence can probe disorder phenotypes at clinical and sub-clinical levels. This detailed review summarizes and critiques the current ¹H-MRS research in ASD. The literature reports reduced N-acetylaspartate (NAA), glutamate and glutamine (Glx), γ-aminobutyric acid (GABA), creatine and choline, and increased glutamate for children with ASD. Adult studies are few and results are inconclusive. Overall, the literature has several limitations arising from differences in ¹H-MRS methodology and sample demographics. We argue that more consistent methods and greater emphasis on phenotype studies will advance understanding of underlying cortical metabolite disturbance in ASD, and the detection, diagnosis, and treatment of ASD and other multi-dimensional psychiatric disorders.