Working memory arrest in children with high-functioning autism compared to children with attention-deficit/hyperactivity disorder: results from a 2-year longitudinal study

Longitudinal changes in executive function in autism spectrum disorder: A systematic review and meta-analyses

Individuals with an autism spectrum disorder (ASD) diagnosis show impairment in executive function (EF). However, findings are mixed regarding differences in the age effect on EF between autistic individuals and persons with typical development (TD). Questions remain regarding whether the age-related trajectories of EF in ASD are the same as or different from those in TD. To bridge this knowledge gap, we conducted a systematic review and meta-analyses of longitudinal studies that compared age-related changes in EF between ASD and TD groups (preregistration: osf.io/j5764). A literature search was conducted using PubMed, PsycINFO, and Web of Science on January 29, 2024. After screening by two independent reviewers, 14 longitudinal studies were included. Random-effects meta-analyses of studies involving a maximum total of 518 autistic and 3558 TD children and adolescents (mean baseline ages: 5.7-12.0 years) showed that ASD had significantly poorer EF than TD at both baseline and follow-up. However, there was no significant group difference in the age-related change in EF across domains, including working memory, inhibition, shifting, and planning. Robust Bayesian meta-analyses also provided substantial evidence in favor of the null hypothesis that ASD and TD groups showed similar changes over time for most EF processes. Limitations of the literature included the limited number of longitudinal studies and a narrow range of developmental stages and EF constructs analyzed across studies. Altogether, these findings suggest that autistic children and adolescents generally can improve in EF over time similarly to their neurotypical peers. This has important implications for parents and educators, encouraging appropriate EF training and intervention for autistic children and adolescents at an early stage.

The long-lasting benefits of pre-kindergarten education on autistic children's working memory development

LAY ABSTRACT

Working memory is an important skill for school success, and it involves holding information in our memory while using it to solve complex problems. However, autistic children often have difficulties with working memory tasks. Also, kindergarteners on the autism spectrum tend to be less school-ready compared with their peers. In addition, children from disadvantaged backgrounds tend to struggle more with working memory and school readiness skills. All preschool-age children on the autism spectrum in the United States are entitled to pre-kindergarten (pre-K) education. However, it is unclear whether attending pre-K helps with children's working memory development in the long run. This study tested whether attending pre-K benefits children's working memory development in the long run. It also tested whether pre-K is especially helpful for autistic children's working memory development. It was found that children who attended pre-K outperformed their peers who did not attend pre-K during the first 2 years of elementary school. However, after first grade, such benefits diminished. Importantly, autistic children who attended pre-K did not demonstrate advanced working memory immediately in kindergarten, but they started to outperform their autistic peers who did not attend pre-K during first grade to third grade. This finding highlights the importance of pre-K education for autistic children in particular. It is also important for educators and parents to understand autistic children's unique learning paths that may be different from non-autistic children. This article discusses specific ways for educators to take full advantage of the long-lasting benefits of pre-K education in autistic children's working memory development.

Early and stable difficulties of everyday executive functions predict autism symptoms and emotional/behavioral problems in preschool age children with autism: a 2-year longitudinal study

Introduction

Longitudinal studies of autistic children show that autism symptoms and emotional/behavioral problems vary and change over time. However, the factors that affect this variability remain far from certain and very little is known about what take place in the preschool period and the role of executive functions (EF).

Methods

Here, we test the influence of stable difficulties in everyday executive functioning (EEF) during early childhood across 2 years on autistic symptoms and emotional and behavioral problems. Twenty-nine autistic children (24 males and 5 females) were assessed twice within the space of 2 years. At baseline (M = 29 months, SD =5.6 months), participants were assessed for EEF, cognitive development, autistic symptoms, and emotional/behavioral problems. At follow-up, we repeated the same assessment except for cognitive development.

Results

The group with stable difficulties (across 2 years) in EEF during early childhood showed a worsening in the severity of autistic symptoms and emotional and behavioral problems compared with children without EEF difficulties (p < 0.05), and these effects cannot be attributable to cognitive development.

Discussion

Our results suggest that early and stable EEF plays the role of a modifier by interacting with the core domains of autism, in particular with the social affect domain (SA CSS), influencing social cognition and exacerbating or lessening symptom expression and emotional behavioral problems. These short-term longitudinal and preliminary findings underscore the importance of EEF as necessary target for early intervention in children with autism.

Working memory of school-aged children on the autism spectrum: Predictors for longitudinal growth

LAY ABSTRACT

Working memory is an important skill for school success, and it involves holding information in our memory while using it to solve complex problems at the same time. Autistic children often have difficulty with working memory. Because working memory development can be easily influenced by many factors from a young age, it is important to find factors that help with autistic children's development. This study tested the factors that are related to autistic children's working memory when they start kindergarten and the factors that can help with rapid improvement throughout their elementary school. We used a nationally representative data set that followed the same group of children from kindergarten to fifth grade. We found that autistic students from backgrounds with more resources and students with advanced learning approaches such as being organized, being excited to learn, and paying careful attention to their work, started school with strong working memory. Autistic students with advanced learning approaches continued to make rapid improvements during the first 3 years, and then their growth slowed down during the last 3 years. Autistic students who had a good relationship with their teachers made rapid improvements during the last 3 years of their elementary school. In addition, autistic children who struggled with working memory upon school entry were more likely to receive special education services at school. These findings suggest that we need effective ways to teach young autistic children important learning-related behaviors from a very young age through the school system, and teachers must prioritize building positive relationships with their students.

Brief Report: Longitudinal Trajectory of Working Memory in School-Aged Children on the Autism Spectrum: Period of High Plasticity and "Late Bloomers"

PURPOSE

While working memory (WM) is a powerful predictor for children's school outcomes, autistic children are more likely to experience delays. This study compared autistic children and their neurotypical peers' WM development over their elementary school years, including relative growth and period of plasticity.

METHODS

Using a nationally-representative dataset, latent growth models were built to examine periods of high plasticity and the relationship between children's performance upon school entry and their relative growth.

RESULTS

While both groups made steeper gains during the early school years, autistic children's period of highest plasticity was prolonged by 1 year, which suggests a larger window for interventions. Further, autistic children who started kindergarten with poorer WM were more likely to make rapid growth during the last 3 years of elementary school, which is when their neurotypical peers' development started to plateau.

CONCLUSION

Findings should prompt various stakeholders to examine interventions and instructions to maximize autistic children's growth in WM. Further, the continued support and monitoring by educators throughout autistic children's late childhood can be particularly beneficial for the "late-bloomers."

Adolescence internalizing problems as a mediator between autism diagnosis in childhood and quality of life in emerging adults with and without autism: a 10-year longitudinal study

BACKGROUND

Individuals with autism tend to have a reduced quality of life across their lifespan. This reduced quality of life may be a result of autism traits, mental distress, and poor person/environment fit. In this longitudinal study, we looked at the role of adolescence internalizing and externalizing problems in mediating the relationship between having an autism diagnosis from childhood and perceived quality of life as emerging adults.

METHODS

A total of 66 participants in a group of emerging adults with autism (mean age 22.2 years), and without autism (mean age 20.9 years) were assessed in three assessment waves (T1 at 12 years, T2 at 14 years, and T3 at 22 years of age). Parents filled out the Child Behavior Checklist at T2 and participants filled out the Perceived Quality of Life Questionnaire at T3. Total and indirect effects were tested in serial mediation analysis.

RESULTS

The results showed that internalizing problems fully mediated the association between childhood autism diagnosis and the quality of life in emerging adulthood, while externalizing problems did not.

CONCLUSION

Our findings suggest that attention to adolescent internalizing problems is important to improve the later quality of life for emerging adults with autism.

Age differences and brain maturation provide insight into heterogeneous results in autism spectrum disorder

Studies comparing individuals with autism spectrum disorder (ASD) to typically developing (TD) individuals have yielded inconsistent results. These inconsistencies reflect, in part, atypical trajectories of development in children and young adults with ASD compared to TD peers. These different trajectories alter group differences between children with and without ASD as they age. This paper first summarizes the disparate trajectories evident in our studies and, upon further investigation, laboratories using the same recruiting source. These studies indicated that cognition improves into adulthood typically, and is associated with the maturation of striatal, frontal, and temporal lobes, but these age-related improvements did not emerge in the young adults with ASD. This pattern - of improvement into adulthood in the TD group but not in the group with ASD - occurred in both social and non-social tasks. However, the difference between TD and ASD trajectories was most robust on a social task, face recognition. While tempting to ascribe this uneven deficit to the social differences in ASD, it may also reflect the prolonged typical development of social cognitive tasks such as face recognition into adulthood. This paper then reviews the evidence on age-related and developmental changes from other studies on ASD. The broader literature also suggests that individuals with ASD do not exhibit the typical improvements during adolescence on skills important for navigating the transition to adulthood. These skills include execution function, social cognition and communication, and emotional recognition and self-awareness. Relatedly, neuroimaging studies indicate arrested or atypical brain maturation in striatal, frontal, and temporal regions during adolescence in ASD. This review not only highlights the importance of a developmental framework and explicit consideration of age and/or stage when studying ASD, but also the potential importance of adolescence on outcomes in ASD.

Visual working memory performance is intact across development in autism spectrum disorder

Autism spectrum disorder (ASD) is associated with atypical visual processing and deficits in working memory (WM). Visual WM performance typically improves between childhood and adulthood, but such improvement may be atypical in ASD. To better understand how visual WM develops, we used a well-established change detection task across multiple visual features. We examined visual WM for color, shape, and pattern in children, adolescents, and adults with and without ASD. VWM capacity and performance for all visual features improved across age similarly for both the TD and ASD groups. While performance was better on set size 4 trials than set size 8 trials for color, shape, and no change trials, such an effect was not evident for pattern change trials. Overall, the present findings suggest that VWM for different visual features may be intact across development in ASD. The ability to hold multiple objects in mind (WM) improves across typical development, but it remains unclear whether such improvement occurs in ASD. We found that developmental improvements in WM for different types of object details (e.g., color, shape, and pattern) is generally similar for both ASD and typical development.

Similar impairments shown on a neuropsychological test battery in adolescents with high-functioning autism and early onset schizophrenia: a two-year follow-up study

Introduction: Cognitive impairments are common in both Autism Spectrum Disorders (ASD) and schizophrenia, but it is unclear whether the pattern of difficulties is similar or different in the two disorders. This cross-sectional and longitudinal study compared the neuropsychological functioning in adolescents with ASD with adolescents with Early Onset Schizophrenia (EOS).Methods: At baseline and at two-year follow-up, participants were assessed with a brief neuropsychological test battery measuring executive functions, visual and verbal learning, delayed recall and recognition and psychomotor speed.Results: We found similar levels of neuropsychological impairment across groups and over time in the adolescents with ASD or EOS. Adolescents in both groups did not improve significantly on verbal learning, verbal delayed recall, visual learning, visual delayed recall or visual delayed recognition, and both groups performed poorer on verbal recognition. Both groups improved on measures of psychomotor processing and executive functions.Conclusion: The findings suggest that it may be difficult to differentiate adolescents with EOS and ASD based on neuropsychological task performance. An implication of the results is that adolescents with either disorder may benefit from a similar approach to the treatment of cognitive impairment in the disorders.

Longitudinal Examination of Everyday Executive Functioning in Children With ASD: Relations With Social, Emotional, and Behavioral Functioning Over Time

Executive functioning (EF) deficits are well-documented in Autism Spectrum Disorder (ASD), yet little is known about the longitudinal trajectory of "everyday" EF and links to social, emotional and behavioral outcomes in ASD. This study examined the profile of everyday EF utilizing parent-reported measures over 2 years, and explored whether prior estimates of EF were related to later co-morbid psychopathology and social functioning in 39 children with ASD and 34 typically developing (TD) children (ages 7-14 years). According to parent reports, children with ASD had impaired scores of EF in all domains at both time points, and showed no significant improvement across 2 years, compared to controls. Regression analyses showed that prior estimates of behavior regulation difficulties at time 1 uniquely predicted later emotional (i.e., symptoms of anxiety/depression) and behavioral (i.e., oppositionality/aggressiveness) problems in children with ASD 2 years later. Furthermore, an improvement of metacognitive skills predicted a reduction of social difficulties over 2 years in ASD. These results imply that EF may be a potential target of intervention for preventing and reducing co-morbid psychopathology and promoting social competence in youth with ASD. Furthermore, the findings that EF related to behavior is more critical for later emotional and behavioral functioning, whereas EF related to cognition is more critical for social functioning, indicates that it may be beneficial to tailor treatment. Future studies investigating the effectiveness of EF-based interventions in improving the cognitive, psychological and social outcomes in ASD are of high priority.

Computerized Cognitive Training in Children With Autism and Intellectual Disabilities: Feasibility and Satisfaction Study

BACKGROUND

Researchers are increasingly interested in testing and developing computerized cognitive training interventions for individuals with autism spectrum disorder due to the limited accessibility of treatments for this disorder. Understanding the feasibility of testing cognitive interventions for this population is critical, especially for individuals with ASD who have low to moderate intellectual ability.

OBJECTIVE

The aim of the study was to evaluate the feasibility of computerized cognitive training as measured by attrition rate and a parent satisfaction survey.

METHODS

A total of 26 participants aged 8-17 years with an autism spectrum disorder diagnosis and significant intellectual impairment were enrolled (mean age 11.1 years). They were instructed to complete 25 sessions of Cogmed Working Memory Training in 5 to 6 weeks with coach assistance. Attrition rate and parent satisfaction surveys were measured after the completion of training.

RESULTS

Most participants (96%, 25/26) completed the training and indicated high satisfaction (>88%). However, among the participants who completed the training, 5 participants (19%) were unable to finish in 6 weeks, the recommended training period by Cogmed. Parents noted various positive (eg, voice-overs) and negative (eg, particular graphic and sounds associated with a stimulus) features of the game that they thought affected their child's response.

CONCLUSIONS

Children with autism spectrum disorder and intellectual impairments can successfully participate in computerized cognitive training interventions but may require additional weeks to complete the training beyond the time needed for children without intellectual impairments. The overall completion rate, with extended time to complete the training, was high. Developers of cognitive training programs for this population should take into account potential issues regarding the noise level of stimuli and characteristics of the visual graphics.

Functional changes during visuo-spatial working memory in autism spectrum disorder: 2-year longitudinal functional magnetic resonance imaging study

This study examined functional changes longitudinally over 2 years in neural correlates associated with working memory in youth with and without autism spectrum disorder, and the impact of increasing cognitive load. We used functional magnetic resonance imaging and a visuo-spatial 1-back task with four levels of difficulty. A total of 14 children with autism spectrum disorder and 15 typically developing children (ages 7-13) were included at baseline and followed up approximately 2 years later. Despite similar task performance between groups, differences were evident in the developmental trajectories of neural responses. Typically developing children showed greater load-dependent activation which intensified over time in the frontal, parietal and occipital lobes and the right fusiform gyrus, compared to those with autism spectrum disorder. Children with autism spectrum disorder showed minimal age-related changes in load-dependent activation, but greater longitudinal load-dependent deactivation in default mode network compared to typically developing children. Results suggest inadequate modulation of neural activity with increasing cognitive demands in children with autism spectrum disorder, which does not mature into adolescence, unlike their typically developing peers. Diminished ability for children with autism spectrum disorder to modulate neural activity during this period of maturation suggests that they may be more vulnerable to the increasing complexity of social and academic demands as they progress through adolescence than their peers.

Metacognitive Aspects of Executive Function Are Highly Associated with Social Functioning on Parent-Rated Measures in Children with Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is characterized by social dysfunction. Even though executive dysfunction has been recognized as important in understanding ASD, the findings are inconsistent. This might be due to different definitions of executive function (EF), which part of EF that has been studied, structured vs. unstructured tasks, inclusion of different moderators (age, IQ, sex) and different diagnostic categories within the spectrum. The main finding is that people with ASD have more EF difficulties than normal controls and more difficulties on open-end tasks than on structured cognitive tasks. Since some EF difficulties may not be observable in a laboratory setting, informant measures might have higher ecological validity than neuropsychological tests. Evidence suggests that executive dysfunctions are associated with social impairments, but few studies have investigated the details of this relationship, and it remains unclear what types of EF deficits are relevant for the social problems of individuals with ASD. Here we investigated which EF domains were associated with various domains of social function on parent-rated measures. A total of 86 children and adolescents with a diagnosis of ASD were included and tested for general cognitive abilities. Parents completed the Behavior Rating Inventory of Executive Function (BRIEF) and the Social Responsiveness Scale (SRS). Multiple regression analysis revealed significant associations between SRS scores and age, sex, total IQ and the BRIEF indexes. The Metacognition Index from the BRIEF added significantly to the prediction of the SRS total score and the subscales Social Communication, Social Motivation and Autistic Mannerisms. The findings suggest that metacognitive aspects of EF are of particular importance for social abilities in children and adolescents with ASD. Earlier research has shown that typically developing (TD) children have a different relationship between EF and social function than children with ASD. They found that in TD children the EF domain related to behavioral regulation was most important to social function. The results from the current study may have implications for understanding the cognitive components of the social problems that define ASD, and may be relevant in developing more targeted clinical EF interventions related to core ASD dysfunctions.

Severity of Autism Symptoms and Degree of Attentional Difficulties Predicts Emotional and Behavioral Problems in Children with High-Functioning Autism; a Two-Year Follow-up Study

Children with autism often struggle with emotional and behavioral problems (EBP). This study investigated whether level of autism symptoms, attention problems or verbal IQ at baseline can predict EBP 2 years later in children with High-Functioning Autism (HFA). Thirty-four participants with HFA and 45 typically developing children (TD) (ages 9-16) were assessed with parent ratings of EBP, autism symptoms, attention problems, and a test of verbal IQ. The amount of autism symptoms and degree of attention problems at baseline significantly predicted EBP at follow-up, whereas verbal IQ did not. The findings from this study emphasize the importance of assessing and understanding the consequences of autism symptoms and attention problems when treating EBP in children with HFA. Furthermore, interventions aimed at improving ASD symptoms may positively affect the prevalence of EBP in children with HFA.

Hot and cool executive function in children and adolescents with autism spectrum disorder: Cross-sectional developmental trajectories

The development of executive function (EF) in autism spectrum disorder (ASD) has only been investigated using "cool"-cognitive-EF tasks. Little is known about the development of "hot"-affective-EF and whether it follows a similar developmental pathway. This study employed a cross-sectional developmental trajectories approach to examine the developmental changes in cool (working memory, inhibition, and planning) and hot EF (delay discounting and affective decision-making) of ASD participants (n = 79) and controls (n = 91) relative to age and IQ, shedding more light on the hot-cool EF organization. The developmental trajectories of some aspects of cool EF (working memory and planning) differed significantly as a function of age in ASD participants relative to controls. For both hot EFs, no significant age-related changes were found in either group. These findings extend our understanding regarding the maturation of EF from childhood through adolescence in ASD.

Social Skills Intervention Participation and Associated Improvements in Executive Function Performance

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairments in social communication. It has been postulated that such difficulties are related to disruptions in underlying cognitive processes such as executive function. The present study examined potential changes in executive function performance associated with participation in the Social Competence Intervention (SCI) program, a short-term intervention designed to improve social competence in adolescents with ASD. Laboratory behavioral performance measures were used to separately evaluate potential intervention-related changes in individual executive function component processes (i.e., working memory, inhibitory control, and cognitive flexibility) in a sample of 22 adolescents with ASD both before and after intervention. For comparison purposes, a demographically matched sample of 14 individuals without ASD was assessed at identical time intervals. Intervention-related improvements were observed on the working memory task, with gains evident in spatial working memory and, to a slightly lesser degree, verbal working memory. Significant improvements were also found for a working memory-related aspect of the task switching test (i.e., mixing costs). Taken together, these findings provide preliminary support for the hypothesis that participation in the SCI program is accompanied by changes in underlying neurocognitive processes such as working memory.

Changing ASD-ADHD symptom co-occurrence across the lifespan with adolescence as crucial time window: Illustrating the need to go beyond childhood

Literature on the co-occurrence between Autism Spectrum Disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD) is strongly biased by a focus on childhood age. A review of the adolescent and adult literature was made on core and related symptoms of ADHD and ASD. In addition, an empirical approach was used including 17,173 ASD-ADHD symptom ratings from participants aged 0 to 84 years. Results indicate that ASD/ADHD constellations peak during adolescence and are lower in early childhood and old age. We hypothesize that on the border of the expected transition to independent adulthood, ASD and ADHD co-occur most because social adaptation and EF skills matter most. Lower correlations in childhood and older age may be due to more diffuse symptoms reflecting respectively still differentiating and de-differentiating EF functions. We plea for a strong research focus in adolescence which may -after early childhood- be a second crucial time window for catching-up pattern explaining more optimal outcomes. We discuss obstacles and oppportunities of a full lifespan approach into old age.

Overactive Pattern Separation Memory Associated with Negative Emotionality in Adults Diagnosed with Autism Spectrum Disorder

Bowler et al. (Journal of Autism and Developmental Disorders 44(9):2355-2362. doi:10.1007/s10803-014-2105-y, 2014) have suggested that a specific memory impairment in autism spectrum disorders (ASD) arises from hippocampal failure to consolidate multiple related pieces of information. Twenty-four adults diagnosed with ASD and matched healthy controls completed a pattern separation memory task that is known to critically depend on hippocampal involvement. They additionally completed questionnaires regarding anxiety, depression, and behavioral motivation. Specific deficits in pattern separation were significantly correlated with negative emotionality; the best predictor of memory deficit was from a measure of achievement motivation that has also been associated with hyperactivity and impulsivity. In the context of impaired emotion regulation in ASD, there is a need for integrated cognitive, affective, and neural systems approaches to build targeted interventions.