Neural and behavioral suppression of interfering flankers by children with and without autism spectrum disorder

Impaired inhibitory control when processing real but not cartoon emotional faces in autistic children: Evidence from an event-related potential study

Impaired socioemotional functioning characterizes autistic children, but does weak inhibition control underlie their socioemotional difficulty? This study addressed this question by examining whether and, if so, how inhibition control is affected by face realism and emotional valence in school-age autistic and neurotypical children. Fifty-two autistic and 52 age-matched neurotypical controls aged 10-12 years completed real and cartoon emotional face Go/Nogo tasks while event-related potentials (ERPs) were recorded. The analyses of inhibition-emotion components (i.e., N2, P3, and LPP) and a face-specific N170 revealed that autistic children elicited greater N2 while inhibiting Nogo trials and greater P3/LPP and late LPP for real but not cartoon emotional faces. Moreover, autistic children exhibited a reduced N170 to real face emotions only. Furthermore, correlation results showed that better behavioral inhibition and emotion recognition in autistic children were associated with a reduced N170. These findings suggest that neural mechanisms of inhibitory control in autistic children are less efficient and more disrupted during real face processing, which may affect their age-appropriate socio-emotional development.

Putting the Spotlight Back Onto the Flanker Task in Autism: Autistic Adults Show Increased Interference from Foils Compared with Non-autistic Adults

Autistic people may have a less focused spotlight of spatial selective attention than non-autistic people, meaning that distracting stimuli are less effectively suppressed. Previous studies using the flanker task have supported this suggestion with observations of increased congruency effects in autistic participants. However, findings across studies have been mixed, mainly based on research in children and on response time measures, which may be influenced by differences in response strategy between autistic and non-autistic people rather than differences in selective attention. In this pre-registered study, 153 autistic and 147 non-autistic adults completed an online flanker task. The aims of this study were to test whether increased congruency effects replicate in autistic adults and to extend previous work by fitting a computational model of spatial selective attention on the flanker task to the data. Congruency effects were increased in the autistic group. The modelling revealed that the interference time from the foils was increased in the autistic group. This suggests that the activation of the foils was increased, meaning suppression was less effective for autistic participants. There were also differences in non-interference parameters between the groups. The estimate of response caution was increased in the autistic group and the estimate of perceptual efficiency was decreased. Together these findings suggest inefficient suppression, response strategy and perceptual processing all contribute to differences in performance on the flanker task between autistic and non-autistic people.

Alpha oscillatory activity during attentional control in children with Autism Spectrum Disorder (ASD), Attention-Deficit/Hyperactivity Disorder (ADHD), and ASD+ADHD

BACKGROUND

Autism Spectrum Disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD) share impairments in top-down and bottom-up modulation of attention. However, it is not yet well understood if co-occurrence of ASD and ADHD reflects a distinct or additive profile of attention deficits. We aimed to characterise alpha oscillatory activity (stimulus-locked alpha desynchronisation and prestimulus alpha) as an index of integration of top-down and bottom-up attentional processes in ASD and ADHD.

METHODS

Children with ASD, ADHD, comorbid ASD+ADHD, and typically-developing children completed a fixed-choice reaction-time task ('Fast task') while neurophysiological activity was recorded. Outcome measures were derived from source-decomposed neurophysiological data. Main measures of interest were prestimulus alpha power and alpha desynchronisation (difference between poststimulus and prestimulus alpha). Poststimulus activity linked to attention allocation (P1, P3), attentional control (N2), and cognitive control (theta synchronisation, 100-600 ms) was also examined. ANOVA was used to test differences across diagnostics groups on these measures. Spearman's correlations were used to investigate the relationship between attentional control processes (alpha oscillations), central executive functions (theta synchronisation), early visual processing (P1), and behavioural performance.

RESULTS

Children with ADHD (ADHD and ASD+ADHD) showed attenuated alpha desynchronisation, indicating poor integration of top-down and bottom-up attentional processes. Children with ADHD showed reduced N2 and P3 amplitudes, while children with ASD (ASD and ASD+ADHD) showed greater N2 amplitude, indicating atypical attentional control and attention allocation across ASD and ADHD. In the ASD group, prestimulus alpha and theta synchronisation were negatively correlated, and alpha desynchronisation and theta synchronisation were positively correlated, suggesting an atypical association between attentional control processes and executive functions.

CONCLUSIONS

ASD and ADHD are associated with disorder-specific impairments, while children with ASD+ADHD overall presented an additive profile with attentional deficits of both disorders. Importantly, these findings may inform the improvement of transdiagnostic procedures and optimisation of personalised intervention approaches.

Beyond group differences: Exploring the preliminary signals of target engagement of an executive function training for autistic children

Understanding both for whom and how interventions work is a crucial next step in providing personalized care to children with autism spectrum disorder (ASD). Autistic children present with heterogeneity both within core ASD criteria and with respect to co‐occurring mental health challenges, which may affect their ability to benefit from intervention. In a secondary data analysis of a randomized control trial evaluating an executive function (EF) training with 70 7‐ to 11‐year‐old autistic children, we explored: (1) whether co‐occurring attention‐deficit/hyperactivity disorder (ADHD) features or anxiety features at baseline moderated the extent to which children benefited from the EF training. In other words, we asked, “For whom is training effective?” We also explored: (2) the extent to which changes in a brain‐based measure of target engagement predicted the clinical outcomes of the EF training. This is a step towards asking, “How is training effective?” We found that EF training improved behavioral inhibition only for children with clinically significant co‐occurring ADHD features. Anxiety features, while prevalent, did not moderate EF training efficacy. Finally, for the EF training group only, there was a significant correlation between pre‐to‐post change in an EEG‐based measure of target engagement, N2 incongruent amplitude during a flanker task, and change in repetitive behaviors, a behavioral outcome that was reported in the parent RCT to have improved with training compared to waitlist control. This study provides preliminary evidence that EF training may differentially affect subgroups of autistic children and that changes at the neural level may precede changes in behavior.

A preliminary randomized, controlled trial of executive function training for children with autism spectrum disorder

LAY ABSTRACT

Executive function, which is a set of thinking skills that includes stopping unwanted responses, being flexible, and remembering information needed to solve problems, is a challenge for many children on the autism spectrum. This study tested whether executive function could be improved with a computerized executive function training program under the guidance of a coach who reinforced the use of executive function skills. Seventy children with autism spectrum disorder from age 7 to 11 years of age participated in the study. They were randomly assigned to receive training or to a waiting group. The tests most likely to determine whether the training may be effective were chosen from a larger battery before the study started and included one task measuring brain responses, two measures of executive function in the lab, and a parent questionnaire. Changes in social functioning and repetitive behaviors were also explored. All children assigned to training completed the program and families generally reported the experience was positive. Brain responses of the training group changed following training, but not within the waiting group during a similar time period. Children who received training did not exhibit behavioral changes during the two the lab-based tasks. Parent report on questionnaires indicated that neither group showed a significant change in their broad use of executive function in other settings. Yet, children who received training were reported to have fewer restricted and repetitive behaviors following training. These initial findings suggest that short executive function training activities are feasible and may improve some functioning of school-aged children on the autism spectrum.

Atypical Neural Responses of Cognitive Flexibility in Parents of Children With Autism Spectrum Disorder

Impaired cognitive flexibility has been repeatedly demonstrated in autism spectrum disorder (ASD). There is strong evidence for genetic involvement in ASD. First-degree relatives of individuals with ASD may show mild deficits in cognitive inflexibility. The present study investigated cognitive flexibility and its neuroelectrophysiological mechanisms in first-degree relatives of individuals with ASD to assess its potential familiality. Forty-five biological parents of individuals/children with ASD (pASD) and thirty-one biological parents of typically developing individuals/children (pTD), matched by gender, age, and IQ, were enrolled. The broad autism phenotype questionnaire (BAPQ) and cognitive flexibility inventory (CFI) were used to quantitatively assess autistic traits and cognitive flexibility in daily life, respectively. The task-switching paradigm was used to evaluate the behavioral flexibility in a structured assessment situation. Event-related potentials (ERPs) induced by this paradigm were also collected. Results showed that compared with the pTD group, the pASD group had lower CFI scores (t = −2.756, p < 0.01), while both groups showed an equivalent “switch cost” in the task-switching task (p > 0.05). Compared with the pTD group, the pASD group induced greater N2 amplitude at F3, F4, Fz, and C4 (F = 3.223, p < 0.05), while P3 amplitude and latency did not differ between the two groups. In addition, there was a significant negative correlation between the CFI total scores and BAPQ total scores in the pASD group (r = −0.734, p < 0.01). After controlling for age and IQ, the N2 amplitude in the frontal lobe of pASD was negatively correlated with the CFI total scores under the repetition sequence (r = −0.304, p = 0.053). These results indicated that pASD had deficit in cognitive flexibility at the self-reported and neurological levels. The cognitive flexibility difficulties of parents of children with ASD were related to autistic traits. These findings support that cognitive flexibility is most likely a neurocognitive endophenotype of ASD, which is worthy of further investigation.

Looking Back at the Next 40 Years of ASD Neuroscience Research

During the last 40 years, neuroscience has become one of the most central and most productive approaches to investigating autism. In this commentary, we assemble a group of established investigators and trainees to review key advances and anticipated developments in neuroscience research across five modalities most commonly employed in autism research: magnetic resonance imaging, functional near infrared spectroscopy, positron emission tomography, electroencephalography, and transcranial magnetic stimulation. Broadly, neuroscience research has provided important insights into brain systems involved in autism but not yet mechanistic understanding. Methodological advancements are expected to proffer deeper understanding of neural circuitry associated with function and dysfunction during the next 40 years.

Alpha connectivity and inhibitory control in adults with autism spectrum disorder

BACKGROUND

Individuals with autism spectrum disorder (ASD) often report difficulties with inhibition in everyday life. During inhibition tasks, adults with ASD show reduced activation of and connectivity between brain areas implicated in inhibition, suggesting impairments in inhibitory control at the neural level. Our study further investigated these differences by using magnetoencephalography (MEG) to examine the frequency band(s) in which functional connectivity underlying response inhibition occurs, as brain functions are frequency specific, and whether connectivity in certain frequency bands differs between adults with and without ASD.

METHODS

We analysed MEG data from 40 adults with ASD (27 males; 26.94 ± 6.08 years old) and 39 control adults (27 males; 27.29 ± 5.94 years old) who performed a Go/No-go task. The task involved two blocks with different proportions of No-go trials: Inhibition (25% No-go) and Vigilance (75% No-go). We compared whole-brain connectivity in the two groups during correct No-go trials in the Inhibition vs. Vigilance blocks between 0 and 400 ms.

RESULTS

Despite comparable performance on the Go/No-go task, adults with ASD showed reduced connectivity compared to controls in the alpha band (8-14 Hz) in a network with a main hub in the right inferior frontal gyrus. Decreased connectivity in this network predicted more self-reported difficulties on a measure of inhibition in everyday life.

LIMITATIONS

Measures of everyday inhibitory control were not available for all participants, so this relationship between reduced network connectivity and inhibitory control abilities may not be necessarily representative of all adults with ASD or the larger ASD population. Further research with independent samples of adults with ASD, including those with a wider range of cognitive abilities, would be valuable.

CONCLUSIONS

Our findings demonstrate reduced functional brain connectivity during response inhibition in adults with ASD. As alpha-band synchrony has been linked to top-down control mechanisms, we propose that the lack of alpha synchrony observed in our ASD group may reflect difficulties in suppressing task-irrelevant information, interfering with inhibition in real-life situations.

Meta-Analysis of the RDoC Social Processing Domain across Units of Analysis in Children and Adolescents

OBJECTIVE

This meta-analysis advances a framework to understand correspondence among units of analysis of the social processing construct within Research Domain Criteria (RDoC).

METHOD

As requested for this special issue, eligible studies cited an RDoC-initiative paper or mentioned RDoC in the abstract, title, or keywords were empirical and peer reviewed, and described a correlation or regression analysis (r, β, or odds ratio) between two different units of analysis in the social processing domain in youth. We examined the frequency (descriptive statistics) and magnitude of correspondence between unit-pairs (random effects models), and predefined moderators (meta-regression).

RESULTS

Eight of the twenty-eight possible unit-by-unit pairs were identified, with subjective-by-behavior units being the most common. Of those, only subjective-by-circuit had significant correspondence between units. Moderator analysis revealed that the age and diagnosis of generalized anxiety disorder moderated correspondence between subjective-by-circuit units of analysis, and that a diagnosis of autism spectrum disorder moderated correspondence between subjective-by-gene units of analysis. Younger ages and inclusion of either diagnostic group reduced correspondence.

CONCLUSIONS

These findings indicate that the RDoC initiative has generated limited research within the social processing domain across units of analysis in youth to date. Moreover, National Institute of Mental Health (NIMH)-funded studies do not appear to be biased toward supporting the RDoC framework. However, the limited number of included studies precludes the generalizability of these findings and underscores the need for further research. Despite this, results suggest that the NIMH model for providing standard batteries of measurement tools may effectively reduce spurious correlations between subjective-by-behavior units of analysis.

Test-retest reliability of the N2 event-related potential in school-aged children with autism spectrum disorder (ASD)

OBJECTIVE

The N2 ERP component is used as a biomeasure of executive function in children with autism spectrum disorder (ASD). The aim of the current study was to evaluate the test-retest reliability of N2 amplitude in this population.

METHODS

ERPs were recorded from 7 to 11-year-old children with ASD during Flanker (n = 21) and Go/Nogo tasks (n = 14) administered at two time points separated by approximately three months. Reliability of the N2 component was examined using intraclass correlation coefficients (ICCs).

RESULTS

Reliability for mean N2 amplitude obtained during the Flanker task was moderate (congruent: ICC = 0.542, 95% CI [0.173, 0.782]; incongruent: ICC = 0.629, 95% CI [0.276, 0.831]). Similarly, reliability for the Go/Nogo task ranged from moderate to good ('go': ICC = 0.817, 95% CI [0.535, 0.937]; 'nogo': ICC = 0.578, 95% CI [0.075, 0.843]).

CONCLUSIONS

These findings support the use of N2 amplitude as a biomeasure of executive function in school-aged children with ASD.

SIGNIFICANCE

This research addresses a critical gap in clinical neurophysiology, as an understanding of the stability and reliability of the N2 component is needed in order to differentiate variance explained by repeated measurement versus targeted treatments and interventions.

Brief Report: Cross-Modal Capture: Preliminary Evidence of Inefficient Filtering in Children with Autism Spectrum Disorder

This study investigates how task-irrelevant auditory information is processed in children with autism spectrum disorder (ASD). Eighteen children with ASD and 19 age- and IQ-matched typically developing (TD) children were presented with semantically-congruent and incongruent picture-sound pairs, and in separate tasks were instructed to attend to only visual or both audio-visual sensory channels. Preliminary results showed that when required to attend to both modalities, both groups were equally slowed for semantically-incongruent compared to congruent pairs. However, when asked to attend to only visual information, children with ASD were disproportionally slowed by incongruent auditory information, suggesting that they may have more difficulty filtering task-irrelevant cross-modal information. Correlational analyses showed that this inefficient cross-modal attentional filtering was related to greater sociocommunicative impairment.

Event-Related Potentials in a Cued Go-NoGo Task Associated with Executive Functions in Adolescents with Autism Spectrum Disorder; A Case-Control Study

Executive functions are often affected in autism spectrum disorders (ASD). The underlying biology is however not well known. In the DSM-5, ASD is characterized by difficulties in two domains: Social Interaction and Repetitive and Restricted Behavior, RRB. Insistence of Sameness is part of RRB and has been reported related to executive functions. We aimed to identify differences between ASD and typically developing (TD) adolescents in Event Related Potentials (ERPs) associated with response preparation, conflict monitoring and response inhibition using a cued Go-NoGo paradigm. We also studied the effect of age and emotional content of paradigm related to these ERPs. We investigated 49 individuals with ASD and 49 TD aged 12-21 years, split into two groups below (young) and above (old) 16 years of age. ASD characteristics were quantified by the Social Communication Questionnaire (SCQ) and executive functions were assessed with the Behavior Rating Inventory of Executive Function (BRIEF), both parent-rated. Behavioral performance and ERPs were recorded during a cued visual Go-NoGo task which included neutral pictures (VCPT) and pictures of emotional faces (ECPT). The amplitudes of ERPs associated with response preparation, conflict monitoring, and response inhibition were analyzed. The ASD group showed markedly higher scores than TD in both SCQ and BRIEF. Behavioral data showed no case-control differences in either the VCPT or ECPT in the whole group. While there were no significant case-control differences in ERPs from the combined VCPT and ECPT in the whole sample, the Contingent Negative Variation (CNV) was significantly enhanced in the old ASD group (p = 0.017). When excluding ASD with comorbid ADHD we found a significantly increased N2 NoGo (p = 0.016) and N2-effect (p = 0.023) for the whole group. We found no case-control differences in the P3-components. Our findings suggest increased response preparation in adolescents with ASD older than 16 years and enhanced conflict monitoring in ASD without comorbid ADHD during a Go-NoGo task. The current findings may be related to Insistence of Sameness in ASD. The pathophysiological underpinnings of executive dysfunction should be further investigated to learn more about how this phenomenon is related to core characteristics of ASD.