No transfer of arousal from other's eyes in Williams syndrome

Typically developing humans automatically synchronize their arousal levels, resulting in pupillary contagion, or spontaneous adaptation of pupil size to that of others. This phenomenon emerges in infancy and is believed to facilitate social interaction. Williams syndrome (WS) is a genetic condition characterized by a hyper-social personality and social interaction challenges. Pupillary contagion was examined in individuals with WS (n = 44), age-parallel-matched typically developing children and adults (n = 65), and infants (n = 79). Bayesian statistics were used. As a group, people with WS did not show pupillary contagion (Bayes factors supporting the null: 25-50) whereas control groups did. This suggests a very early emerging atypical developmental trajectory. In WS, higher pupillary contagion was associated with lower autistic symptoms of social communication. Diminished synchronization of arousal may explain why individuals with WS have social challenges, whereas synchronization of arousal is not a necessary correlate of high social motivation.

Reduced effects of social feedback on learning in Turner syndrome

Turner syndrome is a genetic condition caused by a complete or partial loss of one of the X chromosomes. Previous studies indicate that Turner syndrome is associated with challenges in social skills, but the underlying mechanisms remain largely unexplored. A possible mechanism is a reduced social influence on learning. The current study examined the impact of social and non-social feedback on learning in women with Turner syndrome (n = 35) and a sex- and age-matched control group (n = 37). Participants were instructed to earn points by repeatedly choosing between two stimuli with unequal probabilities of resulting in a reward. Mastering the task therefore required participants to learn through feedback which of the two stimuli was more likely to be rewarded. Data were analyzed using computational modeling and analyses of choice behavior. Social feedback led to a more explorative choice behavior in the control group, resulting in reduced learning compared to non-social feedback. No effects of social feedback on learning were found in Turner syndrome. The current study thus indicates that women with Turner syndrome may be less sensitive to social influences on reinforcement learning, than the general population.

Cognitive profile in adult women with turner syndrome: IQ split and associations with ADHD and ASD

INTRODUCTION

The behavioural phenotype in Turner syndrome (TS) is associated with an uneven cognitive profile and social and executive difficulties. Still, studies in adult populations of TS are scarce, and the interactions between different behavioural domains are unclear. The aim of this study was to examine the cognitive profile in relation to measures of ADHD and ASD in a Swedish sample of 30 adult women with TS.

METHODS

Standardized psychological tests and questionnaires were used for behavioural assessments in a sample of adult women with a diagnosis of TS (n = 30). Both frequentist and Bayesian statistics were applied.

RESULTS

The cognitive profile was characterized by a verbal > non-verbal intelligence quotient (IQ) split, and 77% of the sample displayed a split exceeding cut-off for clinical significance. Symptoms on screening measures reaching thresholds for ADHD were reported in two of the 30 participants (7%) and thresholds for autism spectrum disorders (ASD) in one participant (3%). Bayesian statistics gave substantial evidence for no association between the IQ split and symptoms of ADHD/ASD.

CONCLUSIONS

These results show that the TS phenotype in adulthood is associated with a clinically significant uneven cognitive profile, and particular impairments in integrative executive functions.

Social feedback enhances learning in Williams syndrome

Williams syndrome (WS) is a rare genetic condition characterized by high social interest and approach motivation as well as intellectual disability and anxiety. Despite the fact that social stimuli are believed to have an increased intrinsic reward value in WS, it is not known whether this translates to learning and decision making. Genes homozygously deleted in WS are linked to sociability in the general population, making it a potential model condition for understanding the social brain. Probabilistic reinforcement learning was studied with either social or non-social rewards for correct choices. Social feedback improved learning in individuals with Williams syndrome but not in typically developing controls or individuals with other intellectual disabilities. Computational modeling indicated that these effects on social feedback were mediated by a shift towards higher weight given to rewards relative to punishments and increased choice consistency. We conclude that reward learning in WS is characterized by high volatility and a tendency to learn how to avoid punishment rather than how to gain rewards. Social feedback can partly normalize this pattern and promote adaptive reward learning.

Williams syndrome: on the role of intellectual abilities in anxiety

Background

Individuals with Williams syndrome (WS) have an elevated risk for anxiety disorders throughout the life span, making it a research priority to identify the individual factors associated with anxiety. Most of the existing literature is based on questionnaire data and suggests that impaired executive functions (EF) increase the risk for anxiety in WS. The aim of this study was to use direct measures by trained clinicians to investigate the effects of general intelligence, inhibition, sustained attention, and working memory on anxiety in WS, to further elucidate potential underlying mechanisms.

Method

Twenty-four individuals with WS participated in the study (mean age: 29 years, range: 9–53 years), together with at least one of their parents. The MINI international neuropsychiatric interview for DSM-5 was completed to establish clinical diagnosis of anxiety, and the Clinical Global Impression Scale – Severity was used for an expert rating of symptom severity. Intellectual abilities were measured using the Wechsler scales, and attention and inhibition using the Conner’s Continuous Performance Test. In addition, a parent-report questionnaire measuring EF, learning and memory was collected.

Results

In contrast to the apriori hypothesis, there was no significant association between anxiety and core elements of EF such as working memory, sustained attention, and inhibition (i.e. the process of restraining one’s impulses or behaviour). Using ordinal logistic regression analyses, we showed that decreasing intelligence quotient (IQ) and age are associated with elevated anxiety. We confirmed these results in between-groups analyses (anxiety disorder vs no current anxiety disorder), and low IQ was associated with higher risk of having an anxiety diagnosis. In addition, Bayesian statistics gave substantial evidence for no significant association between anxiety and inhibition.

Conclusion

By using direct measures of psychological pathology and functioning, the current results provide a deeper characterisation of the WS phenotype and provide novel insights into the potential mechanisms underpinning anxiety.

Global and local visual processing in autism - a co-twin-control study

BACKGROUND

Autism Spectrum Disorder (ASD) is associated with altered global and local visual processing. However, the nature of these alterations remains controversial, with contradictory findings and notions ranging from a reduced drive to integrate information into a coherent 'gestalt' ("weak central coherence" = WCC) to an enhanced perceptual functioning (EPF) in local processing.

METHODS

This study assessed the association between autism and global/local visual processing, using a large sample of monozygotic (MZ) and dizygotic (DZ) twins (N = 290, 48% females, age = 8-31 years). The Fragmented Pictures Test (FPT) assessed global processing, whereas local processing was estimated with the Embedded Figures Test (EFT) and the Block Design Test (BDT). Autism was assessed both categorically (clinical diagnosis), and dimensionally (autistic traits). Associations between visual tasks and autism were estimated both across the cohort and within-twin pairs where all factors shared between twins are implicitly controlled.

RESULTS

Clinical diagnosis and autistic traits predicted a need for more visual information for gestalt processing in the FPT across the cohort. For clinical diagnosis, this association remained within-pairs and at trend-level even within MZ twin pairs alone. ASD and higher autistic traits predicted lower EFT and BDT performance across the cohort, but these associations were lost within-pairs.

CONCLUSIONS

In line with the WCC account, our findings indicate an association between autism and reduced global visual processing in children, adolescents and young adults (but no evidence for EPF). Observing a similar association within MZ twins suggests a non-shared environmental contribution.

Social Cognition in Autism and Other Neurodevelopmental Disorders: A Co-twin Control Study

Alterations in social cognition (SC) are hypothesized to underlie social communication and interaction challenges in autism spectrum disorder (ASD). The aetiological underpinnings driving this association remain unclear. We examined SC in 196 twins with ASD, other neurodevelopmental disorders or typical development using the naturalistic Movie for the Assessment of Social Cognition. Autism and its severity were assessed with the Autism Diagnostic Observation Schedule-2, and autistic traits with the Social Responsiveness Scale-2. Using within twin-pair regression models, controlling for age, sex, IQ, and unmeasured familial confounders such as genetic background and shared-environment, SC correlated with ASD diagnosis, autism severity, and autistic traits. Our findings highlight the importance of SC alterations in autism and suggest a non-shared environmental impact on the association.

Dynamical features in fetal and postnatal zinc-copper metabolic cycles predict the emergence of autism spectrum disorder

Metals are critical to neurodevelopment, and dysregulation in early life has been documented in autism spectrum disorder (ASD). However, underlying mechanisms and biochemical assays to distinguish ASD cases from controls remain elusive. In a nationwide study of twins in Sweden, we tested whether zinc-copper cycles, which regulate metal metabolism, are disrupted in ASD. Using novel tooth-matrix biomarkers that provide direct measures of fetal elemental uptake, we developed a predictive model to distinguish participants who would be diagnosed with ASD in childhood from those who did not develop the disorder. We replicated our findings in three independent studies in the United States and the UK. We show that three quantifiable characteristics of fetal and postnatal zinc-copper rhythmicity are altered in ASD: the average duration of zinc-copper cycles, regularity with which the cycles recur, and the number of complex features within a cycle. In all independent study sets and in the pooled analysis, zinc-copper rhythmicity was disrupted in ASD cases. In contrast to controls, in ASD cases, the cycle duration was shorter (F = 52.25, P < 0.001), regularity was reduced (F = 47.99, P < 0.001), and complexity diminished (F = 57.30, P < 0.001). With two distinct classification models that used metal rhythmicity data, we achieved 90% accuracy in classifying cases and controls, with sensitivity to ASD diagnosis ranging from 85 to 100% and specificity ranging from 90 to 100%. These findings suggest that altered zinc-copper rhythmicity precedes the emergence of ASD, and quantitative biochemical measures of metal rhythmicity distinguish ASD cases from controls.

Minor physical anomalies in neurodevelopmental disorders: a twin study

BACKGROUND

Minor physical anomalies (MPAs) are subtle anatomical deviations in one's appearance and may suggest altered embryogenesis. MPAs have been shown to be more common in neurodevelopmental disorders (NDDs) compared with typical development. Still, further studies are needed on MPAs in NDDs, especially using twins to adjust for confounding familial factors.

METHODS

Clinical assessments were conducted on 116 twins (61 NDD, 55 controls) from 51 monozygotic and 7 dizygotic pairs to examine MPAs and their association with DSM-5 defined NDDs. Additionally, the relationship between the number of MPAs within twins by zygosity was investigated.

RESULTS

Within the cohort sample, a specific association was found between MPAs and autism spectrum disorder (ASD) diagnosis (crude odds ratio = 1.29, p = .047; adjusted odds ratios = 1.26-1.33, adjusted p values = .032-.073) and autistic traits (crude β = 3.02, p = .002; adjusted β = 2.28, p = .019), but not NDDs in general or ADHD, nor within-pairs. Identified MPAs in ASD included overweight, hypermobility, pes planus, straight eyebrows, vision impairment, arachnodactyly/long toes, long eyelashes, and microtia. The number of MPAs within all monozygotic pairs was highly correlated (r = .88, p < .001).

CONCLUSION

MPAs are more frequent in participants with ASD and may be influenced by genetics. The value of MPAs for (early) detection should be further explored, as they might index individuals at increased risk for ASD in particular.

The Interrater Reliability of the Autism Diagnostic Interview-Revised (ADI-R) in Clinical Settings

BACKGROUND

The Autism Diagnostic Interview-Revised (ADI-R) is considered a first choice assessment tool in autism spectrum disorder. Nevertheless, despite its wide use in psychiatric practice and recommendations by various clinical guidelines, its interrater reliability has predominantly been confirmed in research settings by specially trained, research reliability interviewers. The reliability of ADI-R assessments among clinicians has not yet been established. Therefore, this study examined the spontaneous interrater reliability of the ADI-R in a naturalistic clinical multicenter setting.

SAMPLING AND METHODS

Ten video-recorded ADI-R administrations were rated by 5 different raters each from a pool of 11 raters affiliated to 8 different clinical sites.

RESULTS

The interrater reliability for the 12 diagnostic criteria operationalizing autism spectrum disorders according to DSM-IV/ICD-10 in the ADI-R algorithms ranged between G(q,k) (analogous to intraclass correlations) = 0.96 and 0.99 for reciprocal social interaction, 0.96 and 1.00 for communication, and 0.91 and 0.97 for repetitive and restricted behavior. Reliability of diagnostic classification was ĸCohen 0.83.

CONCLUSIONS

The findings endorse the psychometric properties of ADI-R in terms of interrater reliability previously reported from research settings and support their generalization to common clinical settings. Limitations of this study include an unbalanced sample composition.

The objectivity of the Autism Diagnostic Observation Schedule (ADOS) in naturalistic clinical settings

The Autism Diagnostic Observation Schedule (ADOS) is a first-choice diagnostic tool in autism spectrum disorder (ASD). Excellent interpersonal objectivity (interrater reliability) has been demonstrated for the ADOS under optimal conditions, i.e., within groups of highly trained "research reliable" examiners in research setting. We investigated the spontaneous interrater reliability among clinically trained ADOS users across multiple sites in clinical routine. Forty videotaped administrations of the ADOS modules 1-4 were rated by five different raters each from a pool of in total 15 raters affiliated to 13 different clinical sites. G(q,k) coefficients (analogous to intraclass correlations), kappas (ĸ) and percent agreement (PA) were calculated. The median interrater reliability for items across the four modules was G(q,k) = .74-.83, with the single ADOS items ranging from .23 to .94. G(q,k) for total scores was .85-.92. For diagnostic classification (ASD/non-spectrum), PA was 64-82 % and Fleiss' ĸ .19-.55. Objectivity was lower for pervasive developmental disorder not otherwise specified and non-spectrum diagnoses as compared to autism. Interrater reliabilities of the ADOS items and domain totals among clinical users across multiple sites were in the same range as previously reported for research reliable users, while the one for diagnostic classification was lower. Differences in sample characteristics, rater skills and statistics compared with previous studies are discussed. Findings endorse the objectivity of the ADOS in naturalistic clinical settings, but also pinpoint its limitations and the need and value of adequate and continuous rater training.