Integration In Autism Spectrum Disorders Research Articles

Heterogeneity of dynamic synergetic configurations of salience network in children with autism spectrum disorder.

Atypical functional connectivity (FC) patterns have been identified in autism spectrum disorders (ASD), especially within salience network (SN) and between SN and default mode network (DMN) and central executive network (CEN). But whether the dynamic configuration of intra-SN and inter-SN (SN with DMN and CEN) FC in ASD is also heterogeneous remains unknown. Based on the resting-state functional magnetic resonance imaging data from 105 ASD and 102 typically-developing controls (TC), we calculated the time-varying FC of intra-SN and inter-SN (SN with DMN and CEN). Then, the joint recurrence features for the time-varying FC were calculated to assess how the SN dynamically recruits different configurations of network segregation and integration in ASD, that is, synergies, from the dynamical systems perspective. We analyzed the differences in synergetic patterns between ASD subtypes obtained by k-means clustering algorithm based on the synergy of SN and TC, and investigated the relationships between synergy of SN and severity of clinical symptoms of ASD for ASD subtypes. Two ASD subtypes were revealed, where the synergy of SN in ASD subtype 1 has lower stability and periodicity compared to the TC, and ASD subtype 2 exhibits the opposite alteration. Synergy of SN for ASD subtype 1 and 2 was found to predict the severity of communication impairments and restricted and repetitive behaviors in ASD, respectively. These results suggest the existence of subtypes with distinct patterns of the synergy of SN in ASD, and provide insight into the complex pathophysiological mechanism of clinical manifestations of ASD.

Topological analysis of brain dynamics in autism based on graph and persistent homology

Autism spectrum disorder (ASD) is a heterogeneous disorder with a rapidly growing prevalence. In recent years, the dynamic functional connectivity (DFC) technique has been used to reveal the transient connectivity behavior of ASDs' brains by clustering connectivity matrices in different states. However, the states of DFC have not been yet studied from a topological point of view. In this paper, this study was performed using global metrics of the graph and persistent homology (PH) and resting-state functional magnetic resonance imaging (fMRI) data. The PH has been recently developed in topological data analysis and deals with persistent structures of data. The structural connectivity (SC) and static FC (SFC) were also studied to know which one of the SC, SFC, and DFC could provide more discriminative topological features when comparing ASDs with typical controls (TCs). Significant discriminative features were only found in states of DFC. Moreover, the best classification performance was offered by persistent homology-based metrics and in two out of four states. In these two states, some networks of ASDs compared to TCs were more segregated and isolated (showing the disruption of network integration in ASDs). The results of this study demonstrated that topological analysis of DFC states could offer discriminative features which were not discriminative in SFC and SC. Also, PH metrics can provide a promising perspective for studying ASD and finding candidate biomarkers.

Sensory and Motor Difficulties in Autism

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterized by difficulties in social interaction and communication, and by restricted and repetitive behaviors. A meta-analysis describes motor difficulties in ASD (Downey and Rapport, 2012) in 85% to 90% of cases (Liu et al. 2010). Electronic devices will help to better characterize these movement impairments (Gargot et al., in press). Another meta-analysis shows difficulties in sensorial integration in ASD, with a prevalence ranging from 45 to 95% (Ben Sasson, 2009). Sensorimotor contigencies are learned interactively (Jacquey et al., 2020), in a perception-action loop, an early milestone in development (Piaget, 1937). A cascade model (Bonnet-Brilhault, 2017) hypothesizes that social difficulties stem in sensorimotor difficulties (Cook, 2016; Neal, 2011; Dziuk et al. 2007; Kojovic, 2019), themselves atypically developed due to a peculiar neurobiological background. This model predicts that early sensorimotor reeducation could prevent the development of social difficulties, whereas the rehabilitation of social skills would improve only part of the impairment, that is driven by sensorimotor processes. How to target these issues? Grandin, 1992 and Edelson et al., 1999 validated the efficacy of deep pressure therapy in ASD. It is important to improve attractivity and decrease the stigmatization of this method. Oto is a compressive armchair with inflatable cushions controlled electronically. It records level of pressure and its duration, chosen by the user. A systematic review showed the efficacy of virtual reality in ASD (Mesa-Gresa et al, 2018). A CAVE device could habituate children to ecological audio-visual stimulations.DisclosureThomas Gargot was paid by the French ministry of research (Doctoral school), French ministry of health (médaille d’argent, CCA-AHU) for a PhD and CCA position. During his PhD, he prepared several scientific presentations with Dr Asselborn. This work led

How the External Visual Noise Affects Motion Direction Discrimination in Autism Spectrum Disorder.

Along with social, cognitive, and behavior deficiencies, peculiarities in sensory processing, including an atypical global motion processing, have been reported in Autism Spectrum Disorder (ASD). The question about the enhanced motion pooling in ASD is still debatable. The aim of the present study was to compare global motion integration in ASD using a low-density display and the equivalent noise (EN) approach. Fifty-seven children and adolescents with ASD or with typical development (TD) had to determine the average direction of movement of 30 Laplacian-of-Gaussian micro-patterns. They moved in directions determined by a normal distribution with a standard deviation of 2°, 5°, 10°, 15°, 25°, and 35°, corresponding to the added external noise. The data obtained showed that the ASD group has much larger individual differences in motion direction thresholds on external noise effect than the TD group. Applying the equivalent noise paradigm, we found that the global motion direction discrimination thresholds were more elevated in ASD than in controls at all noise levels. These results suggest that ASD individuals have a poor ability to integrate the local motion information in low-density displays.

Sensory-to-Cognitive Systems Integration Is Associated With Clinical Severity in Autism Spectrum Disorder

Impaired multisensory integration in autism spectrum disorder (ASD) may arise from functional dysconnectivity among brain systems. Our study examines the functional connectivity integration between primary modal sensory regions and heteromodal processing cortex in ASD, and whether abnormalities in network integration relate to clinical severity. We studied a sample of 55 high-functioning ASD and 64 healthy control (HC) male children and adolescents (total n= 119, age range 7-18 years). Stepwise functional connectivity analysis (SFC) was applied to resting state functional magnetic resonance images (rsfMRI) to characterize the connectivity paths that link primary sensory cortices to higher-order brain cognitive functional circuits and to relate alterations in functional connectivity integration with three clinical scales: Social Communication Questionnaire, Social Responsiveness Scale, and Vineland Adaptive Behavior Scales. HC displayed typical functional connectivity transitions from primary sensory systems to association areas, but the ASD group showed altered patterns of multimodal sensory integration to heteromodal systems. Specifically, compared to the HC group, the ASD group showed the following: (1) hyperconnectivity in the visual cortex at initial link step distances; (2) hyperconnectivity between sensory unimodal regions and regions of the default mode network; and (3) hypoconnectivity between sensory unimodal regions and areas of the fronto-parietal and attentional networks. These patterns of hyper- and hypoconnectivity were associated with increased clinical severity in ASD. Networkwise reorganization in high-functioning ASD individuals affects strategic regions of unimodal-to-heteromodal cortical integration predicting clinical severity. In addition, SFC analysis appears to be a promising approach for studying the neural pathophysiology of multisensory integration deficits in ASD.

Ayres Theories of Autism and Sensory Integration Revisited: What Contemporary Neuroscience Has to Say.

Abnormal sensory-based behaviors are a defining feature of autism spectrum disorders (ASD). Dr. A. Jean Ayres was the first occupational therapist to conceptualize Sensory Integration (SI) theories and therapies to address these deficits. Her work was based on neurological knowledge of the 1970’s. Since then, advancements in neuroimaging techniques make it possible to better understand the brain areas that may underlie sensory processing deficits in ASD. In this article, we explore the postulates proposed by Ayres (i.e., registration, modulation, motivation) through current neuroimaging literature. To this end, we review the neural underpinnings of sensory processing and integration in ASD by examining the literature on neurophysiological responses to sensory stimuli in individuals with ASD as well as structural and network organization using a variety of neuroimaging techniques. Many aspects of Ayres’ hypotheses about the nature of the disorder were found to be highly consistent with current literature on sensory processing in children with ASD but there are some discrepancies across various methodological techniques and ASD development. With additional characterization, neurophysiological profiles of sensory processing in ASD may serve as valuable biomarkers for diagnosis and monitoring of therapeutic interventions, such as SI therapy.

Imagining counterfactual worlds in autism spectrum disorder.

Two experiments are presented that explore online counterfactual processing in autism spectrum disorder (ASD) using eye-tracking. Participants' eye movements were tracked while they read factual and counterfactual sentences in an anomaly detection task. In Experiment 1, the sentences depicted everyday counterfactual situations (e.g., If Joanne had remembered her umbrella, her hair would have been dry/wet when she arrived home). Sentences in Experiment 2 depicted counterfactual versions of real world events (e.g., If the Titanic had not hit an iceberg, it would have survived/sunk along with all the passengers). Results from both experiments suggest that counterfactual understanding is undiminished in adults with ASD. In fact, participants with ASD were faster than Typically Developing (TD) participants to detect anomalies within realistic, discourse-based counterfactuals (Experiment 1). Detection was comparable for TD and ASD groups when understanding could be grounded in knowledge about reality (Experiment 2), though the 2 groups used subtly different strategies for responding to and recovering from counterfactual inconsistent words. These data argue against general difficulties in global coherence and complex integration in ASD. (PsycINFO Database Record

Research on community integration in autism spectrum disorder: Recommendations from research on psychosis

Both individuals with an autism spectrum disorder (ASD) and individuals with a psychotic disorder have difficulties integrating in the community. By means of a systematic review of the literature on community integration of young people with ASD or psychotic disorders, we aimed to unfold research foci and gaps within the ASD literature. As anticipated, research on community integration was more advanced in the field of psychosis compared to ASD. In this paper we highlight those areas of community integration that have received particularly little attention in ASD research, such as stigmatization, and we formulate research recommendations for ASD researchers based on the research conducted in the psychosis field. The outcomes of this systematic review demonstrate a need for more practical research focused on the daily lives of adolescents and adults with ASD.

Self-motion perception in autism is compromised by visual noise but integrated optimally across multiple senses

Perceptual processing in autism spectrum disorder (ASD) is marked by superior low-level task performance and inferior complex-task performance. This observation has led to theories of defective integration in ASD of local parts into a global percept. Despite mixed experimental results, this notion maintains widespread influence and has also motivated recent theories of defective multisensory integration in ASD. Impaired ASD performance in tasks involving classic random dot visual motion stimuli, corrupted by noise as a means to manipulate task difficulty, is frequently interpreted to support this notion of global integration deficits. By manipulating task difficulty independently of visual stimulus noise, here we test the hypothesis that heightened sensitivity to noise, rather than integration deficits, may characterize ASD. We found that although perception of visual motion through a cloud of dots was unimpaired without noise, the addition of stimulus noise significantly affected adolescents with ASD, more than controls. Strikingly, individuals with ASD demonstrated intact multisensory (visual-vestibular) integration, even in the presence of noise. Additionally, when vestibular motion was paired with pure visual noise, individuals with ASD demonstrated a different strategy than controls, marked by reduced flexibility. This result could be simulated by using attenuated (less reliable) and inflexible (not experience-dependent) Bayesian priors in ASD. These findings question widespread theories of impaired global and multisensory integration in ASD. Rather, they implicate increased sensitivity to sensory noise and less use of prior knowledge in ASD, suggesting increased reliance on incoming sensory information.

Memory integration in the autobiographical narratives of individuals with autism.

As part of a unifying theory of autism, Ben Shalom (2009) proposed that while procedural, perceptual and semantic memory functions are intact in Autism Spectrum Disorder (ASD), the more integrative level of episodic memory is impaired. According to Ben Shalom, this reduced integration may be due to the reduced function of the medial prefrontal cortex (mPFC), which may also explain the reduced integration found in motor, sensory-perceptual and emotional processes in ASD. The present review examines this hypothesis, by focusing on evidence regarding autobiographical memory (AM) episodes in ASD—arguably the highest form of memory integration processes. Most research on memory in ASD thus far has focused on memory for experimentally-presented stimuli (Lind, 2010; Boucher et al., 2012). The present paper builds on this literature to examine the rich evidence that has recently accumulated from in-depth, systematic studies of AM in ASD—memories of personally-related events that are naturalistically accumulated over a person's lifetime. Of note, research on AM is limited in its focus on memories that cannot be as readily verified (but see Bruck et al., 2007), and in its reliance on high-functioning verbal individuals. Nonetheless, studies of AM provide us with an unparalleled perspective on the naturalistic process of memory integration in ASD. Specifically, this review aims to determine how well memory episodes are integrated in ASD; which elements become integrated and which do not; whether the ability to form integrated, episodic memories relates to other cognitive and emotional capacities; and how this pattern of integration changes over time. Semantic and episodic autobiographical memory (AM) The declarative memory system comprises semantic and episodic components. Semantic memories are memories of timeless, de-contextualized facts. Episodic memory refers to personal events recollected in the context of a particular time and place, with some reference to oneself as a participant in the episode (Tulving, 2002). Thus, episodic memories involve two functions: the ability to bind different perceptual elements; and, in humans, the ability to perceive of oneself within this context. On a neurobiological level, episodic memory storage and retrieval are thought to involve the interaction of cortical association areas, in which basic sensory information regarding what occurred and where is stored; the hippocampus, which binds these elements into cohesive memories of individual events; and the mPFC, which further contextualizes these events into schemas, such as the self (Preston and Eichenbaum, 2013). AM refers to memory for information pertaining to the self; and while it is often viewed as overlapping with episodic memory, the two are not synonymous (Gilboa, 2004). Episodic memory is a memory system, while AM is a type of content (Gardiner, 2008). Thus, episodic memory functions can encompass both AM and simple phenomena that do not necessarily represent self-relevant information (e.g., source memory). At the same time, AM in fact comprises of both semantic and episodic knowledge (e.g., semantic knowledge of one's date of birth, alongside an episodic memory of one's last birthday). In children with ASD, both semantic and episodic AM is reduced (Bruck et al., 2007; Bon et al., 2012; Goddard et al., 2014), though by adulthood, adults with ASD show a spared memory for semantic AM, alongside reduced episodic AM (Klein et al., 1999; Crane and Goddard, 2008). These studies suggest that as semantic AM may grow in ASD, episodic AM impairments are pervasive. These results fit with the general memory profile in ASD, viz., spared semantic memory alongside difficulties with episodic memory, which is found across experimental studies (Boucher and Bowler, 2008). The present review concerns itself primarily with episodic AM in ASD, though semantic memory will be discussed as it relates to the content of autobiographical narratives.

Evidence for diminished multisensory integration in autism spectrum disorders.

Individuals with autism spectrum disorders (ASD) exhibit alterations in sensory processing, including changes in the integration of information across the different sensory modalities. In the current study, we used the sound-induced flash illusion to assess multisensory integration in children with ASD and typically-developing (TD) controls. Thirty-one children with ASD and 31 age and IQ matched TD children (average age=12years) were presented with simple visual (i.e., flash) and auditory (i.e., beep) stimuli of varying number. In illusory conditions, a single flash was presented with 2-4 beeps. In TD children, these conditions generally result in the perception of multiple flashes, implying a perceptual fusion across vision and audition. In the present study, children with ASD were significantly less likely to perceive the illusion relative to TD controls, suggesting that multisensory integration and cross-modal binding may be weaker in some children with ASD. These results are discussed in the context of previous findings for multisensory integration in ASD and future directions for research.

Multisensory temporal integration in autism spectrum disorders.

The new DSM-5 diagnostic criteria for autism spectrum disorders (ASDs) include sensory disturbances in addition to the well-established language, communication, and social deficits. One sensory disturbance seen in ASD is an impaired ability to integrate multisensory information into a unified percept. This may arise from an underlying impairment in which individuals with ASD have difficulty perceiving the temporal relationship between cross-modal inputs, an important cue for multisensory integration. Such impairments in multisensory processing may cascade into higher-level deficits, impairing day-to-day functioning on tasks, such as speech perception. To investigate multisensory temporal processing deficits in ASD and their links to speech processing, the current study mapped performance on a number of multisensory temporal tasks (with both simple and complex stimuli) onto the ability of individuals with ASD to perceptually bind audiovisual speech signals. High-functioning children with ASD were compared with a group of typically developing children. Performance on the multisensory temporal tasks varied with stimulus complexity for both groups; less precise temporal processing was observed with increasing stimulus complexity. Notably, individuals with ASD showed a speech-specific deficit in multisensory temporal processing. Most importantly, the strength of perceptual binding of audiovisual speech observed in individuals with ASD was strongly related to their low-level multisensory temporal processing abilities. Collectively, the results represent the first to illustrate links between multisensory temporal function and speech processing in ASD, strongly suggesting that deficits in low-level sensory processing may cascade into higher-order domains, such as language and communication.

Brief report: Arrested development of audiovisual speech perception in autism spectrum disorders.

Atypical communicative abilities are a core marker of Autism Spectrum Disorders (ASD). A number of studies have shown that, in addition to auditory comprehension differences, individuals with autism frequently show atypical responses to audiovisual speech, suggesting a multisensory contribution to these communicative differences from their typically developing peers. To shed light on possible differences in the maturation of audiovisual speech integration, we tested younger (ages 6-12) and older (ages 13-18) children with and without ASD on a task indexing such multisensory integration. To do this, we used the McGurk effect, in which the pairing of incongruent auditory and visual speech tokens typically results in the perception of a fused percept distinct from the auditory and visual signals, indicative of active integration of the two channels conveying speech information. Whereas little difference was seen in audiovisual speech processing (i.e., reports of McGurk fusion) between the younger ASD and TD groups, there was a significant difference at the older ages. While TD controls exhibited an increased rate of fusion (i.e., integration) with age, children with ASD failed to show this increase. These data suggest arrested development of audiovisual speech integration in ASD. The results are discussed in light of the extant literature and necessary next steps in research.

Audiovisual speech integration in autism spectrum disorders: ERP evidence for atypicalities in lexical-semantic processing.

In typically developing (TD) individuals, behavioral and event-related potential (ERP) studies suggest that audiovisual (AV) integration enables faster and more efficient processing of speech. However, little is known about AV speech processing in individuals with autism spectrum disorders (ASD). This study examined ERP responses to spoken words to elucidate the effects of visual speech (the lip movements accompanying a spoken word) on the range of auditory speech processing stages from sound onset detection to semantic integration. The study also included an AV condition, which paired spoken words with a dynamic scrambled face in order to highlight AV effects specific to visual speech. Fourteen adolescent boys with ASD (15-17 years old) and 14 age- and verbal IQ-matched TD boys participated. The ERP of the TD group showed a pattern and topography of AV interaction effects consistent with activity within the superior temporal plane, with two dissociable effects over frontocentral and centroparietal regions. The posterior effect (200-300 ms interval) was specifically sensitive to lip movements in TD boys, and no AV modulation was observed in this region for the ASD group. Moreover, the magnitude of the posterior AV effect to visual speech correlated inversely with ASD symptomatology. In addition, the ASD boys showed an unexpected effect (P2 time window) over the frontocentral region (pooled electrodes F3, Fz, F4, FC1, FC2, FC3, FC4), which was sensitive to scrambled face stimuli. These results suggest that the neural networks facilitating processing of spoken words by visual speech are altered in individuals with ASD.

Altered auditory and multisensory temporal processing in autism spectrum disorders.

Autism spectrum disorders (ASD) are characterized by deficits in social reciprocity and communication, as well as by repetitive behaviors and restricted interests. Unusual responses to sensory input and disruptions in the processing of both unisensory and multisensory stimuli also have been reported frequently. However, the specific aspects of sensory processing that are disrupted in ASD have yet to be fully elucidated. Recent published work has shown that children with ASD can integrate low-level audiovisual stimuli, but do so over an extended range of time when compared with typically developing (TD) children. However, the possible contributions of altered unisensory temporal processes to the demonstrated changes in multisensory function are yet unknown. In the current study, unisensory temporal acuity was measured by determining individual thresholds on visual and auditory temporal order judgment (TOJ) tasks, and multisensory temporal function was assessed through a cross-modal version of the TOJ task. Whereas no differences in thresholds for the visual TOJ task were seen between children with ASD and TD, thresholds were higher in ASD on the auditory TOJ task, providing preliminary evidence for impairment in auditory temporal processing. On the multisensory TOJ task, children with ASD showed performance improvements over a wider range of temporal intervals than TD children, reinforcing prior work showing an extended temporal window of multisensory integration in ASD. These findings contribute to a better understanding of basic sensory processing differences, which may be critical for understanding more complex social and cognitive deficits in ASD, and ultimately may contribute to more effective diagnostic and interventional strategies.

Deficit in visual temporal integration in autism spectrum disorders

Individuals with autism spectrum disorders (ASD) are superior in processing local features. Frith and Happe conceptualize this cognitive bias as ‘weak central coherence’, implying that a local enhancement derives from a weakness in integrating local elements into a coherent whole. The suggested deficit has been challenged, however, because individuals with ASD were not found to be inferior to normal controls in holistic perception. In these opposing studies, however, subjects were encouraged to ignore local features and attend to the whole. Therefore, no one has directly tested whether individuals with ASD are able to integrate local elements over time into a whole image. Here, we report a weakness of individuals with ASD in naming familiar objects moved behind a narrow slit, which was worsened by the absence of local salient features. The results indicate that individuals with ASD have a clear deficit in integrating local visual information over time into a global whole, providing direct evidence for the weak central coherence hypothesis.

Bisensory Integration in Autism Spectrum Disorder: an fMRI study

Bisensory Integration in Autism Spectrum Disorder: an fMRI study

Preliminary evidence for deficits in multisensory integration in autism spectrum disorders: The mirror neuron hypothesis

Autism is a complex disorder, characterized by social, cognitive, communicative, and motor symptoms. One suggestion, proposed in the current study, to explain the spectrum of symptoms is an underlying impairment in multisensory integration (MSI) systems such as a mirror neuron-like system. The mirror neuron system, thought to play a critical role in skills such as imitation, empathy, and language can be thought of as a multisensory system, converting sensory stimuli into motor representations. Consistent with this, we report preliminary evidence for deficits in a task thought to tap into MSI—“the bouba-kiki task” in children with ASD. The bouba-kiki effect is produced when subjects are asked to pair nonsense shapes with nonsense “words”. We found that neurotypical children chose the nonsense “word” whose phonemic structure corresponded with the visual shape of the stimuli 88% of the time. This is presumably because of mirror neuron-like multisensory systems that integrate the visual shape with the corresponding motor gestures used to pronounce the nonsense word. Surprisingly, individuals with ASD only chose the corresponding name 56% of the time. The poor performance by the ASD group on this task suggests a deficit in MSI, perhaps related to impaired MSI brain systems. Though this is a behavioral study, it provides a testable hypothesis for the communication impairments in children with ASD that implicates a specific neural system and fits well with the current findings suggesting an impairment in the mirror systems in individuals with ASD.

Brief Report: Can You See What is Not There? Low-level Auditory–visual Integration in Autism Spectrum Disorder

Patients diagnosed with Autism Spectrum Disorder, show impaired integration of information across different senses. The processing-level from which this impairment originates, however, remains unclear. We investigated low-level integration of auditory and visual stimuli in subjects with Autism Spectrum Disorder. High-functioning adult subjects with Autism Spectrum Disorder as well as age- and IQ-matched adults were tested using a task that evokes illusory visual stimuli, by presenting sounds concurrently with visual flashes. In both groups the number of sounds presented significantly affected the number of flashes perceived, yet there was no difference between groups. This finding implicates that any problems arising from integrating auditory and visual information must stem from higher processing stages in high-functioning adults with Autism Spectrum Disorder.