Memory In Autism Spectrum Disorder Research Articles

Circuit mechanism underlying fragmented sleep and memory deficits in 16p11.2 deletion mouse model of autism.

Sleep disturbances are prevalent in children with autism spectrum disorder (ASD) and have a major impact on the quality of life. Strikingly, sleep problems are positively correlated with the severity of ASD symptoms, such as memory impairment. However, the neural mechanisms underlying sleep disturbances and cognitive deficits in ASD are largely unexplored. Here, we show that non-rapid eye movement sleep (NREMs) is highly fragmented in the 16p11.2 deletion mouse model of ASD. The degree of sleep fragmentation is reflected in an increased number of calcium transients in the activity of locus coeruleus noradrenergic (LC-NE) neurons during NREMs. Exposure to a novel environment further exacerbates sleep disturbances in 16p11.2 deletion mice by fragmenting NREMs and decreasing rapid eye movement sleep (REMs). In contrast, optogenetic inhibition of LC-NE neurons and pharmacological blockade of noradrenergic transmission using clonidine reverse sleep fragmentation. Furthermore, inhibiting LC-NE neurons restores memory. Rabies-mediated unbiased screening of presynaptic neurons reveals altered connectivity of LC-NE neurons with sleep- and memory regulatory brain regions in 16p11.2 deletion mice. Our findings demonstrate that heightened activity of LC-NE neurons and altered brain-wide connectivity underlies sleep fragmentation in 16p11.2 deletion mice and identify a crucial role of the LC-NE system in regulating sleep stability and memory in ASD.

Replicable Patterns of Memory Impairments in Children With Autism and Their Links to Hyperconnected Brain Circuits

BackgroundMemory impairments have profound implications for social communication and educational outcomes in children with autism spectrum disorder (ASD). However, the precise nature of memory dysfunction in children with ASD and the underlying neural circuit mechanisms remain poorly understood. The default mode network (DMN) is a brain network that is associated with memory and cognitive function, and DMN dysfunction is among the most replicable and robust brain signatures of ASD. MethodsWe used a comprehensive battery of standardized episodic memory assessments and functional circuit analyses in 25 8- to 12-year-old children with ASD and 29 matched typically developing control children. ResultsMemory performance was reduced in children with ASD compared with control children. General and face memory emerged as distinct dimensions of memory difficulties in ASD. Importantly, findings of diminished episodic memory in children with ASD were replicated in 2 independent data sets. Analysis of intrinsic functional circuits associated with the DMN revealed that general and face memory deficits were associated with distinct, hyperconnected circuits: Aberrant hippocampal connectivity predicted diminished general memory while aberrant posterior cingulate cortex connectivity predicted diminished face memory. Notably, aberrant hippocampal-posterior cingulate cortex circuitry was a common feature of diminished general and face memory in ASD. ConclusionsOur results represent a comprehensive appraisal of episodic memory function in children with ASD and identify extensive and replicable patterns of memory reductions in children with ASD that are linked to dysfunction of distinct DMN-related circuits. These findings highlight a role for DMN dysfunction in ASD that extends beyond face memory to general memory function.

Functional connectivity changes during working memory in autism spectrum disorder: A two-year longitudinal MEG study

Working memory impairments have been reported in adults with autism spectrum disorder (ASD) and associated with functional outcomes and social difficulties. However, little is known about the developmental trajectory of working memory in youth with ASD. The current magnetoencephalography (MEG) study is the first to examine the longitudinal development over two years of working memory networks in youth with ASD. We analysed MEG data from 32 children and adolescents with and without ASD (64 datasets; 7–14 years), all tested twice at a two-year interval, during a visual n-back task, with two loads (1- and 2-back). We performed a whole-brain functional connectivity analysis to examine the networks during the successful recognition of visual stimuli. We demonstrate that youth with ASD show decreased connectivity in the theta frequency (4–7 Hz) in the higher memory load (2-back) condition compared to typically developing (TD) controls. This hypo-connected theta network was anchored in primary visual areas with connections to frontal, parietal and limbic regions. These network differences were found despite similar task performance between ASD and TD groups. Within the TD group, we found an increase in alpha (8–14 Hz) connectivity at Time 2 compared to Time 1 in both the 1- and 2-back conditions. These findings demonstrate the continued development of working memory mechanisms over middle childhood, which were not apparent in youth with ASD. Together, our findings support a network-based approach to understanding atypical neural functioning in ASD and the developmental trajectories of working memory processes over middle childhood.

Intact memory storage but impaired retrieval in visual memory in autism: New insights from an electrophysiological study.

In a recent study on visual episodic memory (Desaunay, Clochon, et al., 2020), we have shown event-related potentials (ERPs) differences associated with priming (150-300 msec), familiarity (350-470 msec), and recollection (600-700 msec), in young people with autism spectrum disorders (ASD) compared with typical development (TD). To go further into the study of the processes of storage and retrieval of the memory trace, we re-analyzed Desaunay, Clochon, et al's data using time-frequency analysis, that is, event-related synchronization and desynchronization (ERS/ERD). This allows a decomposition of the spectral power within frequency bands associated with these ERPs. We focused both on the same time windows and the same regions of interest as previously published. We mainly identified, in ASD compared with TD, reduced ERS in low-frequencies (delta, theta) in early time-windows, and non-significant differences in ERD in higher frequencies (alpha, beta1) in all time-windows. Reduced ERS during recognition confirmed previously reported diminution of priming effects and difficulties in manipulation and retrieval of both semantic and episodic information. Conversely, preserved ERD corroborates a preservation of memory storage processes. These observations are consistent with a cognitive model of memory in ASD, that suggests difficulties in cognitive operations or executive demand at retrieval, subsequent to successful long-term storage of information. LAY SUMMARY: We assessed the EEG synchronization and desynchronization, during visual episodic recognition. We observed, in youth with Autism, reduced synchronization in low-frequencies (delta, theta), suggesting reduced access to and manipulation of long-term stored information. By contrast, non-significant differences in desynchronization at higher frequencies (alpha, beta frequency bands), that support long-term stored semantic and episodic information, suggested preserved memory traces.

Shank2/3 double knockout-based screening of cortical subregions links the retrosplenial area to the loss of social memory in autism spectrum disorders

Members of the Shank protein family are master scaffolds of the postsynaptic architecture and mutations within the SHANK genes are causally associated with autism spectrum disorders (ASDs). We generated a Shank2-Shank3 double knockout mouse that is showing severe autism related core symptoms, as well as a broad spectrum of comorbidities. We exploited this animal model to identify cortical brain areas linked to specific autistic traits by locally deleting Shank2 and Shank3 simultaneously. Our screening of 10 cortical subregions revealed that a Shank2/3 deletion within the retrosplenial area severely impairs social memory, a core symptom of ASD. Notably, DREADD-mediated neuronal activation could rescue the social impairment triggered by Shank2/3 depletion. Data indicate that the retrosplenial area has to be added to the list of defined brain regions that contribute to the spectrum of behavioural alterations seen in ASDs.

Effects of age on the hippocampus and verbal memory in adults with autism spectrum disorder: Longitudinal versus cross-sectional findings.

Research studying aging in adults with autism spectrum disorder (ASD) is growing, but longitudinal work is needed. Autistic adults have increased risk of dementia, altered hippocampal volumes and fornix integrity, and verbal memory difficulties compared with neurotypical (NT) adults. This study examined longitudinal aging in middle-age adults with ASD versus a matched NT group, and compared findings with cross-sectional age effects across a broad adult age range. Participants were 194 adults with (n=106; 74 male) and without (n=88; 52 male) ASD, ages 18-71. Participants (n=45; 40-70 age range) with two visits (2-3 years apart) were included in a longitudinal analysis. Hippocampal volume, fornix fractional anisotropy (FA), and verbal memory were measured via T1-weighted MRI, diffusion tensor imaging, and the Rey Auditory Verbal Learning Test, respectively. Longitudinal mixed models were used for hippocampal system variables and reliable change index categories were used for Auditory Verbal Learning Test analyses. Multivariate regression was used for cross-sectional analyses. Middle-age adults with ASD had greater longitudinal hippocampal volume loss and were more likely to show clinically meaningful decline in short-term memory, compared with NT. In contrast, cross-sectional associations between increasing age and worsening short-term memory were identified in NT, but not autistic adults. Reduced fornix FA and long-term memory in ASD were found across the broad cross-sectional age range. These preliminary longitudinal findings suggest accelerated hippocampal volume loss in ASD and slightly higher rates of clinically-meaningful decline in verbal short-term memory. Contradictory cross-sectional and longitudinal results underscore the importance of longitudinal aging research in autistic adults. LAY SUMMARY: Autistic adults have increased risk of dementia, differences in brain memory structures, and difficulty with memory compared with neurotypical (NT) adults. However, there are no publications that follow the same middle-age autistic adults over time to see how their brain and memory change. Our preliminary findings in a small middle-age autism sample suggest a key memory brain structure, the hippocampus, may shrink faster over 2-3 years compared with NT, and short-term memory may become more challenging for some. Across a broad adult range, autistic adults also had reduced integrity of connections to the hippocampus and greater challenges with long-term memory. In our larger sample across a broad age range, the results did not hint at this aforementioned pattern of accelerated aging. This underscores the importance of more aging research in autism, and especially research where people are followed over time.

Neural Connectivity and Episodic Memory in Autism Spectrum Disorder: A Literature Review

Introduction: There is a growing interest in the social and biological context of episodic memory in children with autism spectrum disorder (ASD). Research has previously found that episodic memory deficits are overrepresented in this population. In an attempt to learn why children with ASD are disproportionately impacted by episodic memory impairments, this paper explores literature from 1970-2020 concerning the relationship between functional connectivity (FC), effective connectivity (EC) and structural connectivity (SC) and episodic memory in children with ASD. Methods: The method of this review involved an extensive literature search in scientific databases for experimental studies and magnetic resonance imaging (MRI) data pertaining to episodic memory in children with ASD. The literature review was conducted by searching for literature in electronic databases (Google Scholar, PubMed and MEDLINE) using the following search words: “ASD and memory,” “episodic memory in ASD,” “connectivity in ASD”. Results: In the studies reviewed, children with ASD consistently underperformed on episodic memory tasks relative to typically developing children. Additionally, the MRI scans of the children with ASD showed hyper- and hypoconnectivity of brain regions across the three connectivity metrics. The results indicated that the abnormalities seen in the FC, SC, and EC of children with ASD is an area of research and intervention opportunity for clinicians. Discussion: Research has found that interventions introduced early to children with autism have the potential to reduce symptoms of ASD before adulthood. Therefore, it is important that early interventions related to improving episodic memory are introduced to children early on to increase quality of life later. Additionally, future research must explore if connectivity abnormalities contribute to ASD or if it precedes ASD diagnosis. As a result, clinicians may also consider adding episodic memory deficits to the diagnostic criteria for ASD since it is overrepresented in this population. Conclusion: Clarifying the relationship between ASD, connectivity, and episodic memory will improve the quality of life of children with ASD in the future. This understanding will have broader implications in children and adults with ASD who struggle with episodic memory in terms of improving their experience in education, work and personal life.

Intact context memory performance in adults with autism spectrum disorder

Research on memory in autism spectrum disorder (ASD) finds increased difficulty encoding contextual associations in episodic memory and suggests executive dysfunction (e.g., selective attention, cognitive flexibility) and deficient metacognitive monitoring as potential contributing factors. Findings from our lab suggest that age-related impairments in selective attention contribute to those in context memory accuracy and older adults tended to show dependence in context memory accuracy between relevant and irrelevant context details (i.e., hyper-binding). Using an aging framework, we tested the effects of selective attention on context memory in a sample of 23 adults with ASD and 23 typically developed adults. Participants studied grayscale objects flanked by two types of contexts (color, scene) on opposing sides and were told to attend to only one object-context relationship, ignoring the other context. At test, participants made object and context recognition decisions and judgment of confidence decisions allowing for an evaluation of context memory performance, hyper-binding, and metacognitive performance for context judgments in a single task. Results showed that adults with ASD performed similarly to typically developed adults on all measures. These findings suggest that context memory performance is not always disrupted in adults with ASD, even when demands on selective attention are high. We discuss the need for continued research to evaluate episodic memory in a wider variety of adults with ASD.

Episodic Autobiographical Memory in Adults With Autism Spectrum Disorder: An Exploration With the Autobiographical Interview.

Introduction: The literature has provided contradictory results regarding the status of episodic memory in autism spectrum disorder (ASD). This might be explained by methodological differences across studies. In the present one, the well-recommended Autobiographical Interview was used in which important aspects of episodic memory were assessed, namely, the number and richness of phenomenological memory details, before and after a retrieval support.Method: Twenty-five well-documented adults with ASD without Intellectual Disability (nine women) and 25 control participants were included and asked to recall six specific autobiographical events. The number and richness of details were assessed globally and for five categories of details (perceptual/sensory, temporal, contextual, emotional, and cognitive), firstly before and then after a specific cueing phase consisting in a series of specific questions to elicit more precise memory details.Results: Cumulatively, from the spontaneous recall to the cueing phase, the number of internal details was lower in ASD individuals compared to controls, but this difference was relevant only after the specific cueing procedure and observed only for contextual details. In contrast, no relevant group difference was observed during spontaneous recall. The detail richness was not impaired in ASD throughout the Autobiographical Interview procedure.Conclusion: Our results speak against a clear impairment of episodicity of autobiographical memory in ASD individuals. They thus challenge previous ones showing both a reduced specificity and episodicity of autobiographical memory in this population and call for further studies to get a better understanding on the status of episodic autobiographical memory in ASD.

Autobiographical Memory in Autism Spectrum Disorder, Attention-Deficit/Hyperactivity Disorder, Hearing Loss, and Childhood Trauma: Implications for Social Communication Intervention.

Purpose Speech-language pathologists (SLPs) work with a variety of populations at risk for poor autobiographical and episodic memory. The purpose of this tutorial is to describe autobiographical memory and how it is affected in children with autism spectrum disorder, attention-deficit/hyperactivity disorder, hearing loss, and childhood trauma, as well as provide clinicians with practical strategies for supporting autobiographical memory in each of these clinical populations. Method This tutorial reviews the literature on (a) autobiographical and episodic memory in typical development; (b) its relation to theory of mind, personal narrative skills, and executive functions; (c) elaborative reminiscing in typical development; (d) how autobiographical memory is impaired in children with autism spectrum disorder, attention-deficit/hyperactivity disorder, hearing loss, and childhood trauma; and (e) strategies for supporting autobiographical memory in each clinical population. Conclusions When adequately prepared, SLPs are uniquely situated to address autobiographical and episodic memory in their work with children, families, and related professionals. This is a long-overdue focus of such great clinical import that justifies its inclusion in the traditional training and preparation of SLPs. Adapting elaborative reminiscing strategies for use with various clinical populations is promising for facilitating healthy EM development and related cognitive functions.

Exploring the Event-Related Potentials' Time Course of Associative Recognition in Autism.

Behavioral data on episodic recollection in autism spectrum disorders (ASD) point limited relational memory functioning. However, the involvement of successive memory processes in the profile of episodic memory in ASD needs more study. Here, we used event-related potentials (ERP) to investigate the time course of episodic recollection with an associative recognition paradigm with picture pairs. Twenty-two participants with ASD and 32 with typical development (TD), all right-handed, were included. Behavioral results confirmed difficulties in correctly recognizing identical pairs in the ASD relative to TD group. We found an unexpected amplitude decrement on the P2 (220-270 msec) and FN400 (350-470 msec) potentials, suggesting diminished priming and familiarity effects in the ASD relative to TD group. However, ERP data revealed that the recognition of associative information relies on the same electrophysiological process (old/new effect in the 600-700-msec late positive component) in ASD participants as in TD ones, with a parietal extension in the ASD group. These results suggest that the electrophysiological processes of associative recognition are qualitatively similar in individuals with and without ASD but may differ quantitatively. This difference may be driven by the reduced early processing of picture pairs that may in turn lead to their diminished integration into the semantic memory system, being partially compensated by a greater involvement of associative memory during the recollection process. Other studies would be useful to go further in identifying these cognitive processes involved in atypical recognition in ASD and their neural substrates. Autism Res 2020, 13: 1998-2016. © 2020 International Society for Autism Research and Wiley Periodicals LLC LAY SUMMARY: We identified diminished performance on the associative recognition of picture pairs in adolescents and young adults with autism when compared to typical development. Electrophysiological data revealed qualitative similarities but quantitative differences between-group, with diminished priming and familiarity processes partially compensated by an enhanced parietal recollection process.

Memory in autism spectrum disorder: A meta-analysis of experimental studies.

To address inconsistencies in the literature on memory in autism spectrum disorder (ASD), we report the first ever meta-analysis of short-term memory (STM) and episodic long-term memory (LTM) in ASD, evaluating the effects of type of material, type of retrieval and the role of interitem relations. Analysis of 64 studies comparing individuals with ASD and typical development (TD) showed greater difficulties in ASD compared with TD individuals in STM (Hedges' g = -0.53, 95% CI [-0.90, -0.16], p = .005, I² = 96%) compared with LTM (g = -0.30, 95% CI [-0.42, -0.17], p < .00001, I² = 24%), a small difficulty in verbal LTM (g = -0.21, p = .01), contrasting with a medium difficulty for visual LTM (g = -0.41, p = .0002) in ASD compared with TD individuals. We also found a general diminution in free recall compared with cued recall and recognition (LTM, free recall: g = -0.38, p < .00001, cued recall: g = -0.08, p = .58, recognition: g = -0.15, p = .16; STM, free recall: g = -0.59, p = .004, recognition: g = -0.33, p = .07). We discuss these results in terms of their relation to semantic memory. The limited diminution in verbal LTM and preserved overall recognition and cued recall (supported retrieval) may result from a greater overlap of these tasks with semantic long-term representations which are overall preserved in ASD. By contrast, difficulties in STM or free recall may result from less overlap with the semantic system or may involve additional cognitive operations and executive demands. These findings highlight the need to support STM functioning in ASD and acknowledge the potential benefit of using verbal materials at encoding and broader forms of memory support at retrieval to enhance performance. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

A Physiological Marker of Recognition Memory in Adults with Autism Spectrum Disorder? - The Pupil Old/New Effect.

This study investigated the pupil Old/New effect in individuals with Autism Spectrum Disorder (ASD) and typical development (TD). Participants studied verbal and visual meaningful and meaningless materials in black and white on a computer screen. Pupil sizes were measured while participants performed a Remember (episodic memory with context)/Know (semantic memory, no context) recognition memory test. ASD compared to TD individuals showed significantly reduced recognition rates for all materials. Both groups showed better memory for visual compared to verbal (picture superiority effect) and meaningful compared to meaningless materials. A pupil size ratio (pupil size for test item divided by baseline) for old (studied) and new (unstudied) materials indicated larger pupils for old compared to new materials only for the TD but not the ASD group. Pupil size in response to old versus new items was positively related to recognition accuracy, confirming that the pupil Old/New effect reflects a memory phenomenon in the ASD group. In addition, this study suggests an involvement of the noradrenergic neurotransmitter system in the abnormal hippocampal functioning in ASD. Implications of these findings, as well as their underlying neurophysiology, will be discussed in relation to current theories of memory in ASD. Autism Res 2020, 13: 627-640. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Most measures of memory in Autism Spectrum Disorder (ASD) depend on verbal answers. In addition to these verbal answers, this study measured the size of the participants' pupil in response to studied and unfamiliar materials revealing memory difficulties in ASD. Measuring pupil size works nonverbally, outside of conscious awareness and forms the basis of studies on less verbal persons with ASD. Mechanisms and brain regions underlying memory differences in ASD are discussed.

Working memory in autism spectrum disorders: does the type of stimulus matter?

ABSTRACT Working memory performance in individuals with autism is a matter of debate in the literature. The purpose of this study was to evaluate the role of stimuli in the working memory of children with and without autism spectrum disorders (ASD). Sixteen children with ASD, clinically diagnosed as high functioning, were matched for gender and age and were compared with 16 typically developing controls. A face perception test and delayed matching task with partially masked faces are used for assessment. The results showed that the performance of both face perception and memorizing tasks is significantly lower in autism during mouth masking when compared to eye masking or without masking faces. We concluded that the performance of working memory in autism depends on the nature of stimuli to be remembered.

Compensatory Hippocampal Recruitment Supports Preserved Episodic Memory in Autism Spectrum Disorder

BackgroundThe degree to which individuals with autism spectrum disorder (ASD) evidence impairments in episodic memory relative to their typically developing (TD) counterparts remains unclear. According to a prominent view, ASD is associated with deficits in encoding associations between items and recollecting precise context details. Here, we evaluated behavioral and neural evidence for this impaired relational binding hypothesis using a task involving relational encoding and recollection during functional magnetic resonance imaging. MethodsAdolescents and young adults (nASD = 47, nTD = 60) performed the Relational and Item-Specific Encoding task during functional magnetic resonance imaging, including item and associative recognition testing. We modeled functional recruitment within the medial temporal lobes (MTLs), and connectivity between MTL and the posterior medial (PM) network thought to underlie relational memory. The impaired relational binding model would predict a behavioral deficit driven by aberrant recruitment and connectivity of MTL and the PM network. ResultsThe ASD and TD groups showed indistinguishable item and associative recognition performance. During relational encoding, the ASD group demonstrated increased hippocampal recruitment, and decreased connectivity between MTL and PM regions relative to the TD group. Within ASD, hippocampal recruitment and MTL-PM connectivity were inversely correlated. ConclusionsThe lack of a behavioral deficit in ASD does not support the impaired relational binding hypothesis. Instead, the current data suggest that increased recruitment of the hippocampus compensates for decreased MTL-PM connectivity to support preserved episodic memory in ASD. These findings suggest a compensatory neurodevelopmental mechanism that may support preserved cognitive domains in ASD: local hyperrecruitment may offset connectivity aberrations in individuals with ASD relative to TD subjects.

Emotional false memory in autism spectrum disorder: More than spared.

To advance what is known about how emotions affect memory in autism spectrum disorder (ASD), we examined emotional false memory for negative, positive, and neutrally valenced photographs comprising scripts of everyday events in a verbal IQ-case matched sample of youth ages 8-14 with ASD (N = 38) and typical development (TYP, N = 38). The groups exhibited many similarities. Their task performance during a recognition task including previously seen and unseen photographs was largely comparable. They evidenced high hit rates for previously viewed photographs, and low false alarm rates for lure photographs that were inconsistent with the scripts. Both ASD and TYP groups showed relatively higher false alarms for lure photographs depicting previously unseen causes of scenario outcomes (causal errors) compared to errors for script-consistent lure photographs that showed extra potentially related events (gap-filling errors). In both groups, task performance was associated with verbal working memory, but not attention deficit hyperactivity, anxiety, or depression symptoms. However, the ASD group made more causal and gap-filling errors on negative and positive, but not neutral, lures compared to TYP, indicating that viewing emotionally valenced stimuli made it harder to discriminate previously seen and unseen photographs. For the ASD group, task performance was associated with compulsive, ritualistic, and sameness behaviors and stereotypic and restricted interests. Findings suggest that the integration of cognition and emotion in ASD is altered and associated with the presence of repetitive behaviors. The impact of these results on the lives of individuals with ASD and implications for psychosocial interventions are discussed. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Visuoconstructive abilities and visuospatial memory in autism spectrum disorder without intellectual disability: Is the role of local bias specific to the cognitive domain tested?

Visuospatial processing in autism spectrum disorder (ASD) without intellectual disability remains only partly understood. The aim of the present study was to investigate global versus local visuospatial processing in individuals with ASD, comparing them with typically developing (TD) controls in visuoconstructive and visuospatial memory tasks. There were 21 participants with ASD without intellectual disability, and 21 TD controls matched for chronological age (M = 161.37 months, SD = 38.19), gender, and perceptual reasoning index who were tested. Participants were administered tasks assessing the visuoconstructive domain and involving fine motor skills, and visuospatial memory tasks in which visuospatial information had to be manipulated mentally. Using a mixed-effects model approach, our results showed different effects of local bias in the ASD group, depending on the domain considered: the use of a local approach only emerged for the visuoconstructive domain-in which fine motor skills were involved. These results seem to suggest that the local bias typical of the cognitive profile of ASD without intellectual disability could be a property of specific cognitive domains rather than a central mechanism. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Executive function predicts the visuospatial working memory in autism spectrum disorder and attention-deficit/hyperactivity disorder.

Children with autism spectrum disorder (ASD) and those with attention deficit/hyperactivity disorder (ADHD) always show working memory deficits. However, research findings on the factors that affected the working memory in ASD and ADHD were inconsistent. Thus, we developed the present study to investigate the association of executive function (EF) with the visuospatial working memory (VSWM) in ASD and ADHD. Three groups of participants were examined: 21 children with ASD, 28 children with ADHD and 28 typically developing (TD) children as the controls. All participants completed two tests: the Wisconsin Card Sorting Test (WCST) and the Corsi Block Tapping Test for measuring EF and VSWM, respectively. The WCST included four domains: categories achieved (CA), perseverative errors (PE), failures to maintain set (FMS), and total errors (TE). The findings indicated that (1) the ASD group showed poorer performance in VSWM than the ADHD and TD groups; (2) for the ASD group, VSWM was positively correlated with CA, and was negatively correlated with PE and TE; (3) for the ADHD group, FMS showed a negative relationship with VSWM; and (4) TE predicted the performance of VSWM in ASD group, while FMS predicted VSWM in ADHD group. The study results suggested that VSWM was impaired in ASD but not in ADHD. Also, the EF domains were differently correlated with the VSWM performance in ASD and ADHD. Our study suggests that we should consider different intervention targets of working memory and EF contributions in improving the cognitive capacity of ASD and ADHD. Autism Res 2018, 11: 1148-1156. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: The present study compared the visuospatial working memory (VSWM) in three groups of children: autism (ASD), attention deficit/hyperactivity disorder (ADHD), and typically developed children (TD). The ASD group showed poorer VSWM than the ADHD and TD groups. The total error of executive function predicted the performance of VSWM in ASD, while failures to maintain set predicted VSWM in ADHD . These findings suggested that we should consider the different working memory and executive function training targets to increase cognitive capacity of ASD and ADHD.

Exploring the neurocognitive basis of episodic recollection in autism

Increasing evidence indicates that the subjective experience of recollection is diminished in autism spectrum disorder (ASD) compared to neurotypical individuals. The neurocognitive basis of this difference in how past events are re-experienced has been debated and various theoretical accounts have been proposed to date. Although each existing theory may capture particular features of memory in ASD, recent research questions whether any of these explanations are alone sufficient or indeed fully supported. This review first briefly considers the cognitive neuroscience of how episodic recollection operates in the neurotypical population, informing predictions about the encoding and retrieval mechanisms that might function atypically in ASD. We then review existing research on recollection in ASD, which has often not distinguished between different theoretical explanations. Recent evidence suggests a distinct difficulty engaging recollective retrieval processes, specifically the ability to consciously reconstruct and monitor a past experience, which is likely underpinned by altered functional interactions between neurocognitive systems rather than brain region-specific or process-specific dysfunction. This integrative approach serves to highlight how memory research in ASD may enhance our understanding of memory processes and networks in the typical brain. We make suggestions for future research that are important for further specifying the neurocognitive basis of episodic recollection in ASD and linking such difficulties to social developmental and educational outcomes.

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.