Autistic traits specific to communication ability are associated with performance on a Mooney face detection task.

Difficulties in global face processing have been associated with autism. However, autism is heterogenous, and it is not known which dimensions of autistic traits are implicated in face-processing difficulties. To address this gap in knowledge, we conducted two experiments to examine how identification of Mooney face stimuli (stylized, black-and-white images of faces without details) related to the six subscales of the Comprehensive Autistic Trait Inventory in young adults. In Experiment 1, regression analyses indicated that participants with poorer communication skills had lower task sensitivity when discriminating between face-present and face-absent images, whilst other autistic traits had no unique predictive value. Experiment 2 replicated these findings and additionally showed that autistic traits were linked to a reduced face inversion effect. Taken together, these results indicate autistic traits, especially communication difficulties, are associated with reduced configural processing of face stimuli. It follows that both reduced sensitivity for identifying upright faces amongst similar-looking distractors and reduced susceptibility to face inversion effects may be linked to relatively decreased reliance on configural processing of faces in autism. This study also reinforces the need to consider the different facets of autism independently.

Visuospatial cueing differences as a function of autistic traits.

Atypical orienting of visuospatial attention in autistic individuals or individuals with a high level of autistic-like traits (ALTs) has been well documented and viewed as a core feature underlying the development of autism. However, there has been limited testing of three alternative theoretical positions advanced to explain atypical orienting - difficulty in disengagement, cue indifference, and delay in orienting. Moreover, research commonly has not separated facilitation (reaction time difference between neutral and valid cues) and cost effects (reaction time difference between invalid and neutral cues) in orienting tasks. We addressed these limitations in two experiments that compared groups selected for Low- and High-ALT levels on exogenous and endogenous versions of the Posner cueing paradigm. Experiment 1 showed that High-ALT participants exhibited a significantly reduced cost effect compared to Low-ALT participants in the endogenous cueing task, although the overall orienting effect remained small. In Experiment 2, we increased task difficulty of the endogenous task to augment cueing effects. Results were comparable to Experiment 1 regarding the finding of a reduced cost effect for High-ALT participants on the endogenous cueing task and additionally demonstrated a reduced facilitation effect in High-ALT participants on the same task. No ALT group differences were observed on an exogenous cueing task included in Experiment 2. These findings suggest atypical orienting in High-ALT individuals may be attributable to general cue indifference, which implicates differences in top-down attentional processes between Low- and High-ALT individuals. We discuss how indifference to endogenous cues may contribute to social cognitive differences in autism.

A review of behavioral evidence for hemispheric asymmetry of visuospatial attention in autism.

Most individuals show a small bias towards visual stimuli presented in their left visual field (LVF) that reflects right-hemispheric specialization of visuospatial functions. Moreover, this bias is altered by some neurodevelopmental disorders, suggesting they may be linked to changes in hemispheric asymmetry. To examine whether autism potentially alters hemispheric asymmetry, we conducted a systematic search of scientific databases to review existing literature on the link between autism and alterations in visuospatial bias. This search identified 13 publications that had explored this issue using a wide range of experimental designs and stimuli. Evidence of reduced LVF bias associated with autism was most consistent for studies examining attentional bias or preference measured using tasks such as line bisection. Findings for studies examining attentional performance (e.g., reaction time) were more equivocal. Further investigation is called for, and we make several recommendations for how this avenue of research can be extended.

No evidence for superior distractor filtering amongst individuals high in autistic-like traits.

Autistic individuals and individuals with high levels of autistic-like traits often show better visual search performance than their neurotypical peers. The present work investigates whether this advantage stems from increased ability to filter out distractors. Participants with high or low levels of autistic-like traits completed an attentional blink task in which trials varied in target-distractor similarity. The results showed no evidence that high levels of autistic-like traits were associated with superior distractor filtering (indexed by the difference in the size of the attentional blink across the high- and low-similarity distractors). This suggests that search advantages seen in previous studies are likely linked to other mechanisms such as enhanced pre-attentive scene processing, better decision making, or more efficient response selection.

The Comprehensive Autistic Trait Inventory (CATI): development and validation of a new measure of autistic traits in the general population.

BACKGROUND: Traits and characteristics qualitatively similar to those seen in diagnosed autism spectrum disorder can be found to varying degrees in the general population. To measure these traits and facilitate their use in autism research, several questionnaires have been developed that provide broad measures of autistic traits [e.g. Autism-Spectrum Quotient (AQ), Broad Autism Phenotype Questionnaire (BAPQ)]. However, since their development, our understanding of autism has grown considerably, and it is arguable that existing measures do not provide an ideal representation of the trait dimensions currently associated with autism. Our aim was to create a new measure of autistic traits that reflects our current understanding of autism, the Comprehensive Autism Trait Inventory (CATI). METHODS: In Study 1, 107 pilot items were administered to 1119 individuals in the general population and exploratory factor analysis of responses used to create the 42-item CATI comprising six subscales: Social Interactions, Communication, Social Camouflage, Repetitive Behaviours, Cognitive Rigidity, and Sensory Sensitivity. In Study 2, the CATI was administered to 1068 new individuals and confirmatory factor analysis used to verify the factor structure. The AQ and BAPQ were administered to validate the CATI, and additional autistic participants were recruited to compare the predictive ability of the measures. In Study 3, to validate the CATI subscales, the CATI was administered to 195 new individuals along with existing valid measures qualitatively similar to each CATI subscale. RESULTS: The CATI showed convergent validity at both the total-scale (r ≥ .79) and subscale level (r ≥ .68). The CATI also showed superior internal reliability for total-scale scores (α = .95) relative to the AQ (α = .90) and BAPQ (α = .94), consistently high reliability for subscales (α > .81), greater predictive ability for classifying autism (Youden's Index = .62 vs .56-.59), and demonstrated measurement invariance for sex. LIMITATIONS: Analyses of predictive ability for classifying autism depended upon self-reported diagnosis or identification of autism. The autistic sample was not large enough to test measurement invariance of autism diagnosis. CONCLUSIONS: The CATI is a reliable and economical new measure that provides observations across a wide range of trait dimensions associated with autism, potentially precluding the need to administer multiple measures, and to our knowledge, the CATI is also the first broad measure of autistic traits to have dedicated subscales for social camouflage and sensory sensitivity.

Magnitude of sex differences in visual search varies with target eccentricity.

A recent meta-analysis found no support for the popular theory that superior visuospatial ability in males is attributable to their relatively greater hemispheric asymmetry of neural functions. However, the issue of whether differences in hemispheric laterality could account for differences in visual perception between the sexes has not been systematically investigated. Visual search is an ideal task for such an investigation, as target-position can be systematically varied across the visual field allowing for a detailed analysis of how performance varies with visual field and eccentricity. We recruited 539 undergraduate participants (150 male) and administered a visual search task that required them to identify the presence of a uniquely-oriented triangle amongst distractors. Crucially, target location was systematically varied over the visual field across trials. Males displayed both superior accuracy and shorter reaction time when targets were presented in the left visual field, whilst sex differences systematically diminished when the target was located further rightward. These behavioural results are in line with the notion that greater hemispheric asymmetry in males influences task performance to a varying extent across the visual field, and illustrates the importance of considering task parameters and the influence of sex in behavioural research.

A comprehensive psychometric analysis of autism-spectrum quotient factor models using two large samples: Model recommendations and the influence of divergent traits on total-scale scores.

The Autism-Spectrum Quotient (AQ) is a psychometric scale that is commonly used to assess autistic-like traits and behaviors expressed by neurotypical individuals. A potential strength of the AQ is that it provides subscale scores that are specific to certain dimensions associated with autism such as social difficulty and restricted interests. However, multiple psychometric evaluations of the AQ have led to substantial disagreement as to how many factors exist in the scale, and how these factors are defined. These challenges have been exacerbated by limitations in study designs, such as insufficient sample sizes as well as a reliance on Pearson, rather than polychoric, correlations. In addition, several proposed models of the AQ suggest that some factors are uncorrelated, or negatively correlated, which has ramifications for whether total-scale scores are meaningfully interpretable-an issue not raised by previous work. The aims of the current study were to provide: (a) guidance as to which models of the AQ are viable for research purposes, and (b) evidence as to whether total-scale scores are adequately interpretable for research purposes. We conducted a comprehensive series of confirmatory factor analyses on 11 competing AQ models using two large samples drawn from an undergraduate population (n = 1,702) and the general population (n = 1,280). Psychometric evidence largely supported using the three-factor model described by Russell-Smith et al. [Personality and Individual Differences 51(2), 128-132 (2011)], but did not support the use of total-scale scores. We recommend that researchers consider using AQ subscale scores instead of total-scale scores. Autism Res 2020, 13: 45-60. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: We examined 11 different ways of scoring subscales in the popular Autism-Spectrum Quotient (AQ) questionnaire in two large samples of participants (i.e., general population and undergraduate students). We found that a three-subscale model that used "Social Skill," "Patterns/Details," and "Communication/Mindreading" subscales was the best way to examine specific types of autistic traits in the AQ. We also found some weak associations between the three subscales-for example, being high on the "Patterns/Details" subscale was not predictive of scores on the other subscales. This means that meaningful interpretation of overall scores on the AQ is limited.

Autistic-traits, not anxiety, modulate implicit emotional guidance of attention in neurotypical adults.

Although autistic and anxious traits are positively correlated, high levels of autistic traits are associated with poorer emotional guidance of attention (EGA) whilst high levels of anxious traits are associated with greater EGA. In order to better understand how these two trait dimensions influence EGA, we simultaneously examined the effects of anxiety and autistic traits in neurotypical adults on target identification in an attentional blink task. Analyses indicated that implicit EGA is attenuated in individuals with higher levels of autistic traits, but largely unaffected by variation in anxious traits. Our results suggest that anxiety plays a comparatively limited role in modulating implicit EGA and reinforces the importance of disentangling correlated individual differences when exploring the effects of personality, including emotional predisposition, on attention.

Modulating attentional biases of adults with autistic traits using transcranial direct current stimulation: A pilot study.

While neurotypical individuals over-attend to the left-side of centrally-presented visual stimuli, this bias is reduced in individuals with autism/high levels of autistic traits. Because this difference is hypothesized to reflect relative reductions in right-hemisphere activation, it follows that increasing right-hemisphere activation should increase leftward bias. We administered transcranial direct current stimulation (tDCS) over the right posterior parietal cortex to individuals with low levels (n = 19) and high levels (n = 19) of autistic traits whilst they completed a greyscales task. Anodal tDCS increased leftward bias for high-trait, but not low-trait, individuals, while cathodal tDCS had no effect. This outcome suggests that typical attentional patterns driven by hemispheric lateralization could potentially be restored following right-hemisphere stimulation in high-trait individuals. Autism Res 2018, 11: 385-390. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Attentional differences between individuals with and without autism may reflect differences in underlying activation of the left and right hemispheres. In this study, we combine an attentional task that reflects relative hemispheric activation with non-invasive cortical stimulation, and show that attentional differences between healthy individuals with low and high levels of autistic-like traits can be reduced. This outcome is encouraging, and suggests that other aspects of attention in autism (e.g., face processing) may stand to benefit from similar stimulation techniques.

Modulation of Global and Local Processing Biases in Adults with Autistic-like Traits.

Previous work shows that doing a continuous performance task (CPT) shifts attentional biases in neurotypical individuals towards global aspects of hierarchical Navon figures by selectively activating right hemisphere regions associated with global processing. The present study examines whether CPT can induce similar modulations of attention in individuals with high levels of autistic traits who typically show global processing impairments. Participants categorized global or local aspects of Navon figures in pre- and post-CPT blocks. Post-CPT, high trait individuals showed increased global interference during local categorization. This result suggests that CPT may be useful for temporarily enhancing global processing in individuals with high levels of autistic traits and possibly those diagnosed with autism.

Reduced Pseudoneglect for Physical Space, but not Mental Representations of Space, for Adults with Autistic Traits.

Neurotypical individuals display a leftward attentional bias, called pseudoneglect, for physical space (e.g. landmark task) and mental representations of space (e.g. mental number line bisection). However, leftward bias is reduced in autistic individuals viewing faces, and neurotypical individuals with autistic traits viewing 'greyscale' stimuli, suggestive of atypical lateralization of attention in autism. We investigated whether representational pseudoneglect for individuals with autistic traits is similarly atypically lateralized by comparing biases on a greyscales, landmark, and mental number line task. We found that pseudoneglect was intact only on the representational measure, the mental number line task, suggesting that mechanisms for atypical lateralization of attention in individuals with autistic traits are specific artefacts of processing physically visual stimuli.

Threatening faces fail to guide attention for adults with autistic-like traits.

Individuals diagnosed with autistic spectrum conditions often show deficits in processing emotional faces relative to neurotypical peers. However, little is known about whether similar deficits exist in neurotypical individuals who show high-levels of autistic-like traits. To address this question, we compared performance on an attentional blink task in a large sample of adults who showed low- or high-levels of autistic-like traits on the Autism Spectrum Quotient. We found that threatening faces inserted as the second target in a rapid serial visual presentation were identified more accurately among individuals with low- compared to high-levels of autistic-like traits. This is the first study to show that attentional blink abnormalities seen in autism extend to the neurotypical population with autistic-like traits, adding to the growing body of research suggesting that autistic-related patterns of behaviors extend into a subset of the neurotypical population. Autism Res 2017, 10: 311-320. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

Individuals with autistic-like traits show reduced lateralization on a greyscales task.

Individuals with autism spectrum conditions attend less to the left side of centrally presented face stimuli compared to neurotypical individuals, suggesting a reduction in right hemisphere activation. We examined whether a similar bias exists for non-facial stimuli in a large sample of neurotypical adults rated above- or below-average on the autism spectrum quotient (AQ). Using the "greyscales" task, we found the typical leftward bias in the below-average group was significantly reduced in the above-average group. Moreover, a negative correlation between leftward bias and the social skills factor of the AQ suggested a link between atypical hemispheric activation and social difficulties in high-AQ trait individuals that extends to non-facial stimuli.

Exploring the repetition paradox: the effects of learning context and massed repetition on memory.

Although repetition is generally assumed to enhance the accessibility of memory for rehearsed material, recent research has suggested that prolonged repetition might actually be detrimental under some conditions. In the present work, we manipulated repetition duration and learning condition (intentional vs. incidental) in an effort to clarify the relationship between repetition and memory. Replicating previous findings, memory for repeated items declined with increased repetition under incidental-learning conditions. However, increased repetition had the opposite effect under intentional-learning conditions. Taken together, these results provide evidence for distinctive mechanisms of memory acquisition during repetition that vary depending on learning context.