Inhibitory Control in Autism Spectrum Disorders: Meta-analyses on Indirect and Direct Measures

Overlap of eating disorders and neurodivergence: the role of inhibitory control

BACKGROUND

Difficulties with inhibitory control have been identified in eating disorders (EDs) and neurodevelopmental disorders (NDs; including attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder), and there appear to be parallels between the expression of these impairments. It is theorised that impairments in inhibitory control within NDs may represent a unique vulnerability for eating disorders (EDs), and this same mechanism may contribute to poorer treatment outcomes. This review seeks to determine the state of the literature concerning the role of inhibitory control in the overlap of EDs and neurodivergence.

METHOD

A scoping review was conducted to summarise extant research, and to identify gaps in the existing knowledge base. Scopus, Medline, PsycInfo, Embase, and ProQuest were systematically searched. Studies were included if the study measured traits of ADHD or autism, and symptoms of ED, and required participants to complete a performance task measure of inhibitory control. Where studies included a cohort with both an ND and ED, these results had to be reported separately from cohorts with a singular diagnosis. Studies were required to be published in English, within the last 10 years.

RESULTS

No studies explored the relationship between autism and EDs using behavioural measures of inhibitory control. Four studies exploring the relationship between ADHD and EDs using behavioural measures of inhibitory control met selection criteria. These studies showed a multifaceted relationship between these conditions, with differences emerging between domains of inhibitory control. ADHD symptoms predicted poorer performance on measures of response inhibition in a non-clinical sample; this was not replicated in clinical samples, nor was there a significant association with EDs. Both ADHD and ED symptoms are associated with poor performance on attentional control measures; where these diagnoses were combined, performance was worse than for those with a singular diagnosis of ADHD. This was not replicated when compared to those with only ED diagnoses.

CONCLUSION

Impairments in attentional control may represent a unique vulnerability for the development of an ED and contribute to poor treatment outcomes. Further research is needed to explore the role of inhibitory control in EDs, ADHD and autism, including the use of both self-report and behavioural measures to capture the domains of inhibitory control.

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.

Case Report: A playful digital-analogical rehabilitative intervention to enhance working memory capacity and executive functions in a pre-school child with autism

Background

Autism Spectrum Disorder (ASD) is often associated with deficits in Working Memory Capacity (WMC) and Executive Functions (EFs), as early as the first years of life. Research has shown that, even young children with ASD, WMC and EF deficits can be effectively addressed through interventions employing digital and/or analogical tools. Early intervention is important because executive dysfunction can negatively impact on the quality of life, both of children and their families. However, very few studies have been carried out involving intervention with pre-schoolers with ASD. To fill this gap, we developed an intervention that promotes pre-schoolers' WMC and EFs by employing both digital apps and analogical playful activities. This study reports on the feasibility of this intervention, which was carried out in a rehabilitative context.

Methods

A male pre-schooler diagnosed with ASD was engaged in a total of 17 intervention sessions, all held in a clinical context, over a nine-week period. Outcomes were measured using a battery of pre- and post-treatment tasks focusing on WMC, EFs and receptive language. The clinician who administered the intervention made written observations and noted any improvements in the child's performance emerging from the digital and analogical activities.

Results

The pre- and post-test scores for the cognitive tasks revealed qualitative improvements in the following cognitive domains: (a) WMC in the language receptive domain; (b) updating in WMC; (c) inhibition, specifically concerning control of motor response; (d) receptive vocabulary. Furthermore, when monitoring the child's performance, the clinician noted improvement in almost all the playful activities. Particularly notable improvements were observed in interaction with the apps, which the child appeared to find very motivating.

Conclusion

This study supports feasibility of a playful digital-analogical intervention conducted by a clinician in a rehabilitation context to promote cognitive abilities in pre-schoolers with ASD. Further studies are needed to establish whether the intervention's effectiveness can be generalized to a broad sample of children with ASD.

Relational memory weakness in autism despite the use of a controlled encoding task

Introduction

Recent work challenged past findings that documented relational memory impairments in autism. Previous studies often relied solely on explicit behavioral responses to assess relational memory integrity, but successful performance on behavioral tasks may rely on other cognitive abilities (e.g., executive functioning) that are impacted in some autistic individuals. Eye-tracking tasks do not require explicit behavioral responses, and, further, eye movements provide an indirect measure of memory. The current study examined whether memory-specific viewing patterns toward scenes differ between autistic and non-autistic individuals.

Methods

Using a long-term memory paradigm that equated for complexity between item and relational memory tasks, participants studied a series of scenes. Following the initial study phase, scenes were re-presented, accompanied by an orienting question that directed participants to attend to either features of an item (i.e., in the item condition) or spatial relationships between items (i.e., in the relational condition) that might be subsequently modified during test. At test, participants viewed scenes that were unchanged (i.e., repeated from study), scenes that underwent an "item" modification (an exemplar switch) or a "relational" modification (a location switch), and scenes that had not been presented before. Eye movements were recorded throughout.

Results

During study, there were no significant group differences in viewing directed to regions of scenes that might be manipulated at test, suggesting comparable processing of scene details during encoding. However, there was a group difference in explicit recognition accuracy for scenes that underwent a relational change. Marginal group differences in the expression of memory-based viewing effects during test for relational scenes were consistent with this behavioral outcome, particularly when analyses were limited to scenes recognized correctly with high confidence. Group differences were also evident in correlational analyses that examined the association between study phase viewing and recognition accuracy and between performance on the Picture Sequence Memory Test and recognition accuracy.

Discussion

Together, our findings suggest differences in the integrity of relational memory representations and/or in the relationships between subcomponents of memory in autism.

Math abilities in autism spectrum disorder: A meta-analysis

BACKGROUND

Studies focusing on math abilities in autism spectrum disorder (ASD) are limited and often provide inconsistent results.

AIM

This meta-analysis was conducted to investigate math abilities in people with autism spectrum disorder (ASD) compared to typically developing (TD) participants.

METHODS AND PROCEDURES

According with PRISMA guidelines, a systematic search strategy was adopted. First, 4405 records were identified through database searching; then, the title-abstract screening led to the identification of 58 potentially relevant studies and, finally, after the full-text screening, 13 studies were included.

OUTCOMES AND RESULTS

Results shows that the group with ASD (n = 533) performed lower than the TD group (n = 525) with a small-to-medium effect (g=0.49). The effect size was not moderated by task-related characteristics. Instead, sample-related characteristics, specifically age, verbal intellectual functioning, and working memory, were significant moderators.

CONCLUSIONS AND IMPLICATIONS

This meta-analysis shows that people with ASD have poorer math skills than their TD peers, suggesting the importance of investigating math abilities in autism, taking into account the role of moderating variables.

Emotion Regulation and Executive Function: Associations with Depression and Anxiety in Autism

Background

Adolescents and young adults with autism spectrum disorder (ASD) are prone to experience co-occurring mental health conditions such as mood or anxiety disorders, as well as impairments in emotion regulation and executive functioning. However, little research has examined inter-relationships among these constructs, despite evidence of additional stressors and increased risk of internalizing disorders at this age, relative to non-autistic individuals. If either emotion regulation or executive functioning are shown to have patterns of association with mental health, this can inform mechanism-based intervention.

Method

Fifty-seven autistic adolescents and adults (16-25 years) with ASD in a transition intervention completed questionnaires and clinician-administered measures at baseline. Analyses assessed whether executive functioning impairment, above and beyond emotion regulation impairment, were associated with depression and anxiety symptoms.

Results

ASD characteristics, emotion regulation, anxiety, and depression were significantly correlated. ASD characteristics was a significant contributor to depression and emotion regulation impairments were significant contributors to anxiety and depression. Findings indicated that inhibition difficulties did not uniquely contribute to depression or anxiety above emotion regulation impairment. Difficulties in cognitive flexibility were associated with depression above and beyond ASD characteristics, IQ, and emotion regulation, but not associated with anxiety.

Conclusions

Although preliminary, findings suggest that inflexibility and regulatory impairment should be considered in depression remediation approaches. Improving ER, on the other hand, may have broader transdiagnostic impact across both mood and anxiety symptoms in ASD.

Evaluating in the Real-World Educational Intervention to Improve Interference Control in Children with Autism Spectrum Disorder

Children with autism spectrum disorder (ASD) present deficiencies in interference control processes. The main aim of this pilot study was to analyze the efficacy of an educational intervention designed to optimize the interference control of eight ASD children, attending to their ASD severity level. A mixed-methods approach grounded in systematic observation and nomothetic/follow-up/multidimensional observational designs was used. An observation instrument was developed to code data, which were grouped according to the ASD severity level (Group 1, requires support; Group 2, requires substantial support) and were analyzed using a lag sequential analysis. The results show that, although both groups progressed during the intervention and could have continued to improve, each group evolved differently. Group 1 performed relatively well from the onset and increased and developed their interference control strategies throughout the intervention, while Group 2, despite also acquiring new interference control strategies, took more time to show improvements. One month after the intervention ended, both groups were unable to consolidate the strategies learned. A mixed-methods approach allowed for real interference control deficits in ASD children to be captured in a natural context. To conclude, it would be necessary to lengthen this intervention and adapt it to the needs of each group.

Cognitive and behavioral profiles in children with autism spectrum disorder with and without Attention-Deficit/hyperactivity disorder

BACKGROUND

Understanding the developmental trajectories of children with autism spectrum disorder (ASD) with and without comorbid ADHD is relevant to tailor care plans. This prospective study assessed, for the first time, cognitive, emotional, behavioral, and learning outcomes in adolescence of children with ASD-ADHD and in those with ASD+ADHD in childhood. Possible predictors of severity of ASD core symptoms in adolescence were also evaluated.

METHODS

Forty-five adolescents without intellectual disability, 26 diagnosed in childhood with ASD-ADHD and 19 with ASD+ADHD, were evaluated at baseline (mean age: 8.6 ± 1.3) and at 5-year follow-up (mean age: 12.9 ± 0.9). Parents and teachers completed questionnaires on executive functions, theory of mind (ToM), emotional/behavioral difficulties (EBD), and learning style at both time points..

RESULTS

Overall different developmental trajectories for the two groups were found. In general, deficits in metacognition processes, ToM skills, EBD, and learning abilities were more pronounced in the ASD+ group. Over time, the ASD+ADHD group, but not the ASD-ADHD, tended to improve in EBD and metacognition but their level of development continued to be lower compared with ASD+ADHD. EBD in childhood were significant predictors of autism core symptoms of adolescents.

CONCLUSIONS

Our findings highlight the importance of an early identification of comorbid ADHD symptoms in ASD to offer treatment strategies based on specific developmental trajectories.