Adaptation to vocal expressions and phonemes is intact in autism spectrum disorder

Several recent studies have demonstrated reduced visual aftereffects, particularly to social stimuli, in autism spectrum disorder (ASD). This putative impairment of the adaptive mechanism in ASD has been put forward as a possible explanation for some of the core social problems experienced by children with ASD (e.g., facial emotion or identity recognition). We addressed this claim in children with ASD and typically developing children by using an established methodology and morphed auditory stimulus set for eliciting robust aftereffects to vocal expressions and phonemes. Although children with ASD were significantly worse at categorizing the vocal expressions compared with the control stimuli (phoneme categorization), aftereffect sizes in both tasks were identical in the two participant groups. Our finding suggests that the adaptation mechanism is not universally impaired in ASD and is therefore not an explanation for the social perception difficulties in ASD

Inferior Frontal Gyrus Volume Loss Distinguishes Between Autism and (Comorbid) Attention-Deficit/Hyperactivity Disorder—A FreeSurfer Analysis in Children

Objective: Autism spectrum (ASD) and attention-deficit/hyperactivity disorder (ADHD) are neurodevelopmental disorders with a high rate of comorbidity. To date, diagnosis is based on clinical presentation and distinct reliable biomarkers have been identified neither for ASD nor ADHD. Most previous neuroimaging studies investigated ASD and ADHD separately.Method: To address the question of structural brain differences between ASD and ADHD, we performed FreeSurfer analysis in a sample of children with ADHD (n = 30), with high-functioning ASD (n = 14), with comorbid high-functioning ASD and ADHD (n = 15), and of typically developed controls (TD; n = 36). With FreeSurfer, an automated brain imaging processing and analyzing suite, we reconstructed the cerebral cortex and calculated gray matter volumes as well as cortical surface parameters in terms of cortical thickness and mean curvature.Results: A significant main effect of the factor ADHD was detected for the left inferior frontal gyrus (Pars orbitalis) volume, with the ADHD group exhibiting smaller Pars orbitalis volumes. Dimensional measures of autism (SRS total raw score) and ADHD (DISYPS-II FBB-ADHD score) had no significant influence on the left Pars orbitalis volume. Both, ASD and ADHD tended to have an effect on cortical thickness or mean curvature, which did not survive correction for multiple comparisons.Conclusion: Our results underline that ADHD rather than ASD is associated with volume loss in the left inferior frontal gyrus (Pars orbitalis). This area might play a relevant role in modulating symptoms of inattention and/or impulsivity in ADHD. The effect of comorbid ADHD in ASD samples and vice versa, on cortical thickness and mean curvature, requires further investigation in larger samples

Intra-Subject Variability, Intelligence, and ADHD Traits in a Community-Based Sample

Objective: The present study investigates the predictive validity of intra-subject variability (ISV) for ADHD traits in a community-based sample and the stability of the relationship between ISV and fluid intelligence (gf) across the continuum of ADHD traits. Method: Age-residualized data from 426 participants (8-18 years, 6% ADHD) was used to investigate whether ex-Gaussian and DDM parameters derived from simple choice-reaction-time tasks can predict continuously assessed ADHD traits. Multiple-Group-Analyses and Latent-Moderated-Structural-Equations were used to test whether ADHD traits moderate the relationship between ISV and gf. Results: sigma and mu of the ex-Gaussian model as well as DDM parameters drift rate (v) and boundary separation (a) significantly predicted general ADHD traits, while tau predicted attention difficulties specifically. Across the ADHD continuum, sigma and v were significant predictors of gf. Conclusion: The results confirm the link between ISV and ADHD. The relationship between ISV and gf appears stable across the ADHD continuum

Media Use, Sleep Quality, and ADHD Symptoms in a Community Sample and a Sample of ADHD Patients Aged 8 to 18 Years

Objective: Relationships between sleep, screen-based media, and ADHD symptomatology were investigated using a case- and community-based approach. Method: N = 357 healthy and N = 61 children with ADHD (12.72 +/- 2.83 years) completed a sleep and media questionnaire. To measure ADHD symptomatology, parents filled out the Strengths and Weaknesses of ADHD symptoms and Normal behavior (SWAN) scale. Two samples were formed: a matched (N = 61 patients and N = 61 controls) and a community sample (N = 357 healthy participants and N = 20 patients). Results: Compared with controls, participants with ADHD reported delayed sleep onset and more screen time on school days. Adolescent patients showed more behavior promoting delayed sleep phase. In the community sample, media time, sleep deviation, and circadian rhythm were correlated with ADHD symptomatology. Furthermore, media time, sleep-wake behavior, and sleep deviation were predictive of ADHD symptomatology (variance explained = 4%-15%). Conclusion: Longer media time and inadequate sleep-wake behavior increase the risk of ADHD-like symptoms. However, research using objective assessments is needed to disentangle this distinct association and to provide possible directions for intervention

Identification of neuromotor deficits common to autism spectrum disorder and attention deficit/hyperactivity disorder, and imitation deficits specific to autism spectrum disorder

Deficits in motor and imitation abilities are a core finding in autism spectrum disorders (ASD), but impaired motor functions are also found in attention deficit/hyperactivity disorder (ADHD). Given recent theorising about potential aetiological overlap between the two disorders, the present study aimed to assess difficulties in motor performance and imitation of facial movements and meaningless gestures in a sample of 24 ADHD patients, 22 patients with ASD, and 20 typically developing children, matched for age (6-13 years) and similar in IQ (> 80). Furthermore, we explored the impact of comorbid ADHD symptoms on motor and imitation performance in the ASD sample and the interrelationships between the two groups of variables in the clinical groups separately. The results show motor dysfunction was common to both disorders, but imitation deficits were specific to ASD. Together with the pattern of interrelated motor and imitation abilities, which we found exclusively in the ASD group, our findings suggest complex phenotypic, and possibly aetiological, relationships between the two neurodevelopmental conditions

Attention for Emotion-How Young Adults With Neurodevelopmental Disorders Look at Facial Expressions of Affect

While Autism Spectrum Disorder (ASD), Attention-Deficit/Hyperactivity Disorder (ADHD) and Schizophrenia (SCZ) differ in many clinically relevant features such as symptomatology and course, they may also share genetic underpinnings, affective problems, deviancies in social interactions, and are all characterized by some kind of cognitive impairment. This situation calls for a joint investigation of the specifics of cognitive (dys-)functions of the three disorders. Such endeavor should focus, among other domains, on the inter-section of processing cognitive, affective and social information that is crucial in effective real-life interactions and can be accomplished when attentional preferences for human facial expressions of emotions is studied. To that end, attention to facial expressions of basic emotions was examined in young adults with ASD, ADHD, or SCZ in the present study. The three clinical groups were compared with an age-matched group of typically-developing participants (TD) during the free contemplation of five different facial emotions presented simultaneously, by varying identities, through the registration of eye movements. We showed, that dwell times and fixation counts differed for the different emotions in TD and in a highly similar way in ADHD. Patients with ASD differed from TD by showing a stronger differentiation between emotions and partially different attentional preferences. In contrast, the SCZ group showed an overall more restricted scanning behavior and a lack of differentiation between emotions. The ADHD group, showed an emotion-specific gazing pattern that was highly similar to that of controls. Thus, by analyzing eye movements, we were able to differentiate three different viewing patterns that allowed us to distinguish between the three clinical groups. This outcome suggests that attention for emotion may not tap into common pathophysiological processes and argues for a multi-dimensional approach to the grouping of disorders with neurodevelopmental etiology