Core Deficits In Autism Research Articles

Is it up to language? Pragmatic competence in Croatian preschool children with autism and typical development

Objectives The relationship between structural language ability and pragmatics is not fully understood, in either individuals with autism or those with typical development (TD). Despite the well-established understanding that core deficits in autism lie in pragmatics, specific pragmatic behaviours that distinguish autistic children (AC) from their TD peers are not sufficiently described. The aims of this study were as follows: to investigate the differences in language abilities and pragmatic competence between AC and those with TD; to examine the relationship between language comprehension/production and pragmatic competence in both groups; and to identify the items of pragmatic composite that are most discriminative in detecting AC. Methods The participants in this study were preschool-aged children with TD (N = 45; mean age 65.5 months) and AC with average nonverbal IQ scores (N = 32; mean age 72.9 months). Language production and comprehension abilities were assessed using the New Reynell Developmental Language Scales (4th edition), and pragmatic competence was measured using the Children’s Communication Checklist (CCC). Results For all language and pragmatic variables, AC performed worse than those with TD. Pragmatic competencies did not correlate with structural language skills in either group, except for a correlation between language production and coherence in the TD. Finally, certain pragmatic behaviours common to many AC and rarely found in children with TD were identified as potential distinguishing features between the two groups. Conclusions This study underscores the importance of incorporating pragmatic assessments alongside traditional language evaluations and suggests that interventions should target pragmatic competence specifically, especially in preschool AC.

The Use of One-Part Directives in Developing Play Skills in Children With Autism During Trial-Based Instructions

Play is one of the core deficits in autism. Children with autism have very different play behavior. The current study examines the of using a one-part directive during trial-based instructions on developing play skills in young children with autism. With the use of Single-subject research as an in-depth type of quantitative study of the response of an individual or a group of individuals to intervention. Participants were five children diagnosed with autism ages three to five years old. The task was introduced in a single case design across all sessions in both generalization settings. The participants seemed to have no apparent intervention effects, and one showed a decrease in play following the intervention. The possible reasons for the variability across participants and suggestions for improving methods in developing play skills are discussed. Acquisition and generalization of play skills may be affected not only by which play skills are taught but also by how play skills are taught. The careful selection of play activities may develop spontaneous play among children with autism and their peers.

The Use of One-Part Directives in Developing Play Skills in Children with Autism during Trial-Based Instructions

Play is one of the core deficits in autism. Children with autism have very different play behavior. The current study examines the use of a one-part directive during trial-based instructions on developing play skills in young children with autism. Single-subject research is an in-depth quantitative study of the response of an individual or a group of individuals to intervention. Participants were five children diagnosed with autism ages three to five years old. The task was introduced in a single case design across all sessions in both generalization settings. The participants seemed to have no apparent intervention effects, and one showed a decrease in play following the intervention. The possible reasons for the variability across participants and suggestions for improving methods in developing play skills are discussed. Acquisition and generalization of play skills may be affected by which play skills are taught and how plays skills are taught. Carefully selecting play activities may develop spontaneous play among children with autism and their peers.

Reduced Primacy Bias in Autism during Early Sensory Processing.

Recent theories of autism propose that a core deficit in autism would be a less context-sensitive weighting of prediction errors. There is also first support for this hypothesis on an early sensory level. However, an open question is whether this decreased context sensitivity is caused by faster updating of one's model of the world (i.e., higher weighting of new information), proposed by predictive coding theories, or slower model updating. Here, we differentiated between these two hypotheses by investigating how first impressions shape the mismatch negativity (MMN), reflecting early sensory prediction error processing. An autism and matched control group of human adults (both n = 27, 8 female) were compared on the multi-timescale MMN paradigm, in which tones were presented that were either standard (frequently occurring) or deviant (rare), and these roles reversed every block. A well-replicated observation is that the initial model (i.e., the standard and deviant sound in the first block) influences MMN amplitudes in later blocks. If autism is characterized by faster model updating, and thus a smaller primacy bias, we hypothesized (and demonstrate using a simple reinforcement learning model) that their MMN amplitudes should be less influenced by the initial context. In line with this hypothesis, we found that MMN responses in the autism group did not differ between the initial deviant and initial standard sounds as they did in the control group. These findings are consistent with the idea that autism is characterized by faster model updating during early sensory processing, as proposed by predictive coding accounts of autism.SIGNIFICANCE STATEMENT Recent theories of autism propose that a core deficit in autism is that they are faster to update their models of the world based on new sensory information. Here, we tested this hypothesis by investigating how first impressions shape brain responses during early sensory processing, and hypothesized that individuals with autism would be less influenced by these first impressions. In line with earlier studies, our results show that early sensory processing was influenced by first impressions in a control group. However, this was not the case in an autism group. This suggests that individuals with autism are faster to abandon their initial model, and is consistent with the proposal that they are faster to update their models of the world.

Effects and Moderators of a Short Theory of Mind Intervention for Children with Autism Spectrum Disorder: A Randomized Controlled Trial.

Limited perspective taking or "Theory of Mind" (ToM) abilities are a core deficit of autism, and many interventions are aimed to improve ToM abilities. In this study, we investigated the effectiveness of a ToM treatment for children with autism spectrum disorders (ASD) and, for the first time, the moderating roles of social interaction style (SIS) and disruptive behavior (DB), to determine which children are most likely to respond to this intervention. The trial protocol is registered at www.trialregister.nl, trial number 2327 and published before the data collection was finished (www.trialsjournal.com). Children with autism aged 7-12 years (n = 97) were randomized over a waitlist control or a treatment condition. Outcome measures included ToM and emotion understanding, parent and teacher questionnaires on children's social skills, ToM-related social behavior, and autistic traits. Six-month follow-up parent reported data were collected for the treatment group. The treatment had a positive effect on ToM understanding, parent-reported ToM behavior, and autistic traits, but not on parent or teacher-reported social behavior. Passive SIS was associated with diminished treatment effects on autistic traits, but DB was unrelated to outcomes. The ToM intervention improved conceptual social understanding and ToM-related behavior of children with ASD. However, broader application of learned skills to other domains of functioning was limited. Individual differences with regard to treatment response are discussed.

Two to Ten Years: Developmental Trajectories of Joint Attention in Children With ASD Who Received Targeted Social Communication Interventions

This study follows 40 children who were participants in a randomized controlled early intervention trial (Kasari et al.) from early childhood (2-5 years of age) to elementary school age (8-10 years). To fully utilize the available longitudinal data, the general linear mixed model was the primary analytical approach. The growth trajectories of joint attention skills (pointing, coordinated joint looking, and showing) and expressive language outcomes in these children were estimated based on five time points during the measurement period. The children were grouped by diagnosis at the last follow-up (autism, autism spectrum disorder (ASD), no diagnosis) and by their original treatment group assignment (joint attention, symbolic play, control), and differences between these groups were evaluated. Results showed that joint attention skills of coordinated joint looking and showing increased over time, and pointing to share interest increased over the first year measured and decreased thereafter. These trajectories were influenced by both original treatment assignment and diagnostic status at follow-up. In addition, a cross-lagged panel analysis revealed a causal relationship between early pointing and later language development. This study highlights the longitudinal and developmental importance of measures of early core deficits in autism, and suggests that both treatment and ASD symptomatology may influence growth in these skills over time.

Reduced Serotonin Receptor Subtypes in a Limbic and a Neocortical Region in Autism

Autism is a behaviorally defined, neurological disorder with symptom onset before the age of 3. Abnormalities in social-emotional behaviors are a core deficit in autism, and are characterized by impaired reciprocal-social interaction, lack of facial expressions, and the inability to recognize familiar faces. The posterior cingulate cortex (PCC) and fusiform gyrus (FG) are two regions within an extensive limbic-cortical network that contribute to social-emotional behaviors. Evidence indicates that changes in brains of individuals with autism begin prenatally. Serotonin (5-HT) is one of the earliest expressed neurotransmitters, and plays an important role in synaptogenesis, neurite outgrowth, and neuronal migration. Abnormalities in 5-HT systems have been implicated in several psychiatric disorders, including autism, as evidenced by immunology, imaging, genetics, pharmacotherapy, and neuropathology. Although information is known regarding peripheral 5-HT in autism, there is emerging evidence that 5-HT systems in the central nervous system, including various 5-HT receptor subtypes and transporters, are affected in autism. The present study demonstrated significant reductions in 5-HT1A receptor-binding density in superficial and deep layers of the PCC and FG, and in the density of 5-HT(2A) receptors in superficial layers of the PCC and FG. A significant reduction in the density of serotonin transporters (5-HTT) was also found in the deep layers of the FG, but normal levels were demonstrated in both layers of the PCC and superficial layers of the FG. This study provides potential substrates for decreased 5-HT modulation/innervation in the autism brain, and implicate two 5-HT receptor subtypes as potential neuromarkers for novel or existing pharmacotherapies.

Teacher-implemented joint attention intervention: Pilot randomized controlled study for preschoolers with autism.

The vast majority of children with an autism spectrum disorder (ASD) attend public preschools at some point in their childhood. Community preschool practices often are not evidence based, and almost none target the prelinguistic core deficits of ASD. This study investigated the effectiveness of public preschool teachers implementing a validated intervention (the Joint Attention and Symbolic Play/Engagement and Regulation intervention; JASP/ER) on a core deficit of autism, initiating joint attention. Sixteen dyads (preschoolers with ASD and the public school teachers who worked in the child's classroom) were randomly assigned to the 6-week JASP/ER intervention or a control group. At the end of the intervention, JASP/ER teachers used more JASP/ER strategies than the control teachers, and JASP/ER preschoolers used more joint attention in their classroom than control children. Additionally, JASP/ER children spent more time in supported engagement and less time in object engagement than control preschoolers on a taped play interaction. Findings suggest that teachers were able to improve a core deficit of children with ASD in a public preschool context.

Assessing Diverse Students With Autism Spectrum Disorders

Assessing Diverse Students With Autism Spectrum Disorders

Addressing parental concerns at the initial diagnosis of an autism spectrum disorder

The core deficits in autism spectrum disorders (ASDs) include socialization, communication, and the presence of repetitive, stereotypical interests and behaviors. In addition to these core problems the autism spectrum includes a variety of possible developmental delays, intellectual disabilities, medical issues, and co-morbid psychiatric disorders. As each child may present with a unique set of difficulties, it may be difficult for clinicians to adequately address each families concerns at the time of diagnosis. The object of this study was to assess what problems were of foremost important to parents at the time of their child's ASD diagnosis and to determine how well they felt those concerns were addressed during the diagnostic process. Four-hundred and thirty-eight parents of children with an ASD completed web-based surveys collecting demographic information and assessing areas of concern and how well those concerns were addressed at diagnosis. At the time of diagnosis, core deficits were of most important to respondents but were considered well addressed only about half of the time. Also important was discussing information about treatments options with the diagnosing clinician. Clinicians could better address the core deficits in autism and their treatment options at the time they make an ASD diagnosis.

Testing autism interventions: trials and tribulations

In The Lancet today, Jonathan Green and colleagues 1 Green J Charman T McConachie H et al. the PACT ConsortiumParent-mediated communication-focused treatment in children with autism (PACT): a randomised controlled trial. Lancet. 2010; (published online May 21.)https://doi.org/10.1016/S0140-6736(10)60587-9 Summary Full Text Full Text PDF Scopus (478) Google Scholar report results from a multisite randomised trial in children with autism. The investigators compared a parent-training technique that targeted enhancement of the child's social-communication skills (two of the three core deficits in autism) with treatment as usual. The primary outcome was the social-communication score from the Autism Diagnostic Observation Schedule (ADOS), 2 Lord C Rutter M DiLavore PC Risi S Autism Diagnostic Observation Schedule (ADOS). Western Psychological Services, Los Angeles, CA1999 Google Scholar a widely used diagnostic tool. Secondary outcomes included parent–child interaction, child language, social communication, and measures of adaptive functioning. Parent-mediated communication-focused treatment in children with autism (PACT): a randomised controlled trialOn the basis of our findings, we cannot recommend the addition of the PACT intervention to treatment as usual for the reduction of autism symptoms; however, a clear benefit was noted for parent-child dyadic social communication. Full-Text PDF Open AccessDepartment of ErrorSpence SJ, Thurm A. Testing autism interventions: trials and tribulations. Lancet 2010; 375: 2124–25—In this Comment (June 19), the affiliation for both authors should have been: “Pediatrics and Developmental Neuroscience Branch, Intramural Research Program of the National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA”. This correction has been made to the online version as of Dec 3, 2010. Full-Text PDF

Nonverbal deficit to understand others’ minds in high function autism spectrum disorders

Deficits in understanding others’ minds, evident in most individuals with autism spectrum disorders, have been suggested as a core deficit of autism. However, nonverbal ability has gone untested because most theory of mind measurement has involved verbal materials such as reading tasks. This raises the possibility that children with high function autism spectrum disorder would distinguish verbal and nonverbal component deficits. Thirty-two participants diagnosed with autism spectrum disorder by a trained psychiatrist and 34 matched controls were recruited for this study. The assessment included verbal and non-verbal materials tasks. The result showed that nonverbal ability of theory of mind is impaired in the individuals with autism spectrum disorders.

The Ethics of Autism: Among Them, but Not of Themby Deborah R. Barnbaum; Bloomington, Indiana University Press, 2008, 233 pages, $55 hardcover, $21.95 softcover

Back to table of contents Previous article Next article Book ReviewFull AccessThe Ethics of Autism: Among Them, but Not of ThemH. Steven Moffic M.D.H. Steven Moffic M.D.Search for more papers by this authorPublished Online:1 Jun 2009https://doi.org/10.1176/ps.2009.60.6.853AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail That famous saying goes, "We've come a long way, baby!" When I first started to practice in psychiatry back in 1978, there wasn't much that could be done to help autism, a disorder erroneously thought to be caused by "cold" mothering. We now know enough about genetics to think about the possibility of someday preventing autism. We also know about providing some degree of useful treatment for the disorder, which has prompted the author of this book to ask the following provocative question: If a "cure" for autism became available, should we use it? Although I have been writing ethics columns and heading ethics committees for years now, I never encountered a question quite like this one.Perhaps because the book was written by a philosopher, much of it might not seem relevant or interesting to the everyday clinician. However, there are brief first-person accounts, usually of successful adaptations, interspersed throughout the philosophical discussions that help make some of the conundrums come alive.Although this is an oversimplification for such a rich discussion, the core deficit of autism is theorized in this volume as an inability to understand and empathize with other people, as well as a corresponding lack of being able to understand oneself. This may be some kind of failure of what we now call the "mirror neurons" of the brain. Given the nature of these differences from persons without the disorder, the author makes a fascinating and convincing case that autism challenges our basic conception about what it means to be human, or at least a social human. Consequently, whether those with autism can understand society's basic moral standards and expectations is debatable. Informed consent then becomes questionable, including participation in research studies or treatment, especially as adults.By the end of the book, the author seems to conclude—and I would agree—that very early intervention should be provided not only to reduce later morbidity but also so that the person with autism will arrive at a comfortable identity in his or her development. Should a "cure" become available, adults with autism, unless they have major behavioral problems, may fare best with their usual treatment, both because they often seem satisfied and because drastic change would be an unimaginable challenge to their identity.However, there may be an even larger ethical conundrum. In passing, the author mentions that about 10% of people with autism have special talents in, for example, music, painting, or spatial configurations. Beyond the obvious benefit of such gifts in themselves, there may be a broader implication here, in that some researchers feel these gifts may someday be accessible to persons who do or do not have autism. Therefore, "curing" autism more generally, if and when that becomes possible, could close a window for potentially learning enough to access those abilities more readily for the general population.Probably because the author is not a clinician, the pain to families and others significant in the life of persons with autism is relatively ignored and underplayed, as are the enormous social and financial costs involved in trying to integrate persons with autism into society. There are also some broader implications that may be of interest to clinicians. One is the ethical consideration of drawbacks of treatment if it also reduces something valued. That question comes up frequently in regard to those who are creative and whether their creativity may be positively connected to a hypomanic or mild depressive state. In my practice this question often comes up with treatment of attention-deficit hyperactivity disorder (ADHD). Consider Olympic star Michael Phelps, who is reported to have ADHD, which has gone untreated for years. This leaves clinicians with the ethical necessity to always balance and discuss potential benefits with potential losses, risks, and side effects. "Do no harm" whatsoever is generally and practically impossible.The reviewer reports no competing interests.Dr. Moffic is professor of psychiatry and behavioral medicine and community and family medicine, Medical College of Wisconsin, Milwaukee. FiguresReferencesCited byDetailsCited ByNone Volume 60Issue 6 June, 2009Pages 853-854PSYCHIATRIC SERVICES June 2009 Volume 60 Number 6 Metrics PDF download History Published online 1 June 2009 Published in print 1 June 2009

The Ethics of Autism: Among Them, but Not of Them

Back to table of contents Previous article Next article Book ReviewFull AccessThe Ethics of Autism: Among Them, but Not of ThemH. Steven Moffic M.D.H. Steven Moffic M.D.Search for more papers by this authorPublished Online:1 Jun 2009https://doi.org/10.1176/ps.2009.60.6.853AboutSectionsView articleView PDFView EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail View articleThat famous saying goes, "We've come a long way, baby!" When I first started to practice in psychiatry back in 1978, there wasn't much that could be done to help autism, a disorder erroneously thought to be caused by "cold" mothering. We now know enough about genetics to think about the possibility of someday preventing autism. We also know about providing some degree of useful treatment for the disorder, which has prompted the author of this book to ask the following provocative question: If a "cure" for autism became available, should we use it? Although I have been writing ethics columns and heading ethics committees for years now, I never encountered a question quite like this one.Perhaps because the book was written by a philosopher, much of it might not seem relevant or interesting to the everyday clinician. However, there are brief first-person accounts, usually of successful adaptations, interspersed throughout the philosophical discussions that help make some of the conundrums come alive.Although this is an oversimplification for such a rich discussion, the core deficit of autism is theorized in this volume as an inability to understand and empathize with other people, as well as a corresponding lack of being able to understand oneself. This may be some kind of failure of what we now call the "mirror neurons" of the brain. Given the nature of these differences from persons without the disorder, the author makes a fascinating and convincing case that autism challenges our basic conception about what it means to be human, or at least a social human. Consequently, whether those with autism can understand society's basic moral standards and expectations is debatable. Informed consent then becomes questionable, including participation in research studies or treatment, especially as adults.By the end of the book, the author seems to conclude—and I would agree—that very early intervention should be provided not only to reduce later morbidity but also so that the person with autism will arrive at a comfortable identity in his or her development. Should a "cure" become available, adults with autism, unless they have major behavioral problems, may fare best with their usual treatment, both because they often seem satisfied and because drastic change would be an unimaginable challenge to their identity.However, there may be an even larger ethical conundrum. In passing, the author mentions that about 10% of people with autism have special talents in, for example, music, painting, or spatial configurations. Beyond the obvious benefit of such gifts in themselves, there may be a broader implication here, in that some researchers feel these gifts may someday be accessible to persons who do or do not have autism. Therefore, "curing" autism more generally, if and when that becomes possible, could close a window for potentially learning enough to access those abilities more readily for the general population.Probably because the author is not a clinician, the pain to families and others significant in the life of persons with autism is relatively ignored and underplayed, as are the enormous social and financial costs involved in trying to integrate persons with autism into society. There are also some broader implications that may be of interest to clinicians. One is the ethical consideration of drawbacks of treatment if it also reduces something valued. That question comes up frequently in regard to those who are creative and whether their creativity may be positively connected to a hypomanic or mild depressive state. In my practice this question often comes up with treatment of attention-deficit hyperactivity disorder (ADHD). Consider Olympic star Michael Phelps, who is reported to have ADHD, which has gone untreated for years. This leaves clinicians with the ethical necessity to always balance and discuss potential benefits with potential losses, risks, and side effects. "Do no harm" whatsoever is generally and practically impossible.The reviewer reports no competing interests.Dr. Moffic is professor of psychiatry and behavioral medicine and community and family medicine, Medical College of Wisconsin, Milwaukee. FiguresReferencesCited byDetailsCited ByNone Volume 60Issue 6 June, 2009Pages 853-854PSYCHIATRIC SERVICES June 2009 Volume 60 Number 6 Metrics History Published online 1 June 2009 Published in print 1 June 2009

Event related potentials in the understanding of autism spectrum disorders: an analytical review.

In this paper we critically review the literature on the use of event related potentials (ERPs) to elucidate the neural sources of the core deficits in autism. We review auditory and visual ERP studies, and then review the use of ERPs in the investigation of executive function. We conclude that, in autism, impairments likely exist in both low and higher level auditory and visual processing, with prominent impairments in the processing of social stimuli. We also discuss the putative neural circuitry underlying these deficits. As we look to the future, we posit that tremendous insight can be gained by applying ERPs to the definition of endophenotypes, which, in turn, can facilitate early diagnosis and the creation of informed interventions for children with autism.

Behavior patterns in Duchenne muscular dystrophy: Report on the Parent Project Muscular Dystrophy behavior workshop 8–9 of December 2006, Philadelphia, USA

Eighteen participants representing clinicians, scientists, parents, industry, and public health agencies involved in the assessment and treatment of children with Duchenne muscular dystrophy (DMD) from Australia, Canada, the Netherlands, the UK and the USA met in Philadelphia on December 8–9, 2006 to attend a workshop addressing behavioral issues among children and young adults with DMD. The workshop, sponsored by Parent Project Muscular Dystrophy (PPMD–USA), was organized in response to parent and clinician concerns regarding behavior associated with DMD, and its subsequent impact on patient and family quality of life. For the purposes of clarification, in this report the term ‘‘behavior’’ is defined as readily observable external actions and responses, as well as internal affective/emotional states. The aims of the workshop were to (1) evaluate current findings and determine whether characteristic behaviors occur among boys and young men with DMD, (2) examine etiological factors contributing to behavior patterns in DMD, and (3) develop recommendations for research and intervention strategies. DMD is a genetic disorder occurring in approximately one in 3300 live male births. Mutations in the dystrophin gene result in an absence of dystrophin or a non-functional dystrophin protein. The different types and locations of the mutation are highly variable across individuals, and it is

Improvement in Sensory Impairment and Social Interaction in Young Children with Autism Following Treatment with an Original Qigong Massage Methodology

In clinical research, sensory impairment is considered one of the core deficits in autism and is associated with impaired socialization, behavioral disturbances and bowel and sleep problems. The effectiveness of the Cignolini methodology, an original Qigong massage methodology, in treating sensory impairment in young children with autism was evaluated in a small, controlled study. Thirteen children with autism between the ages of three and six received daily treatment according to the methodology for 5 months. Compared with untreated children, treated children experienced significant improvement of their sensory impairment (p < 0.01), and demonstrated increased social skills (p < 0.04) and basic living skills (p < 0.02) on standardized measures. In addition, all of the children with bowel and sleep abnormalities demonstrated improvement after treatment.

The mirror neuron system and the consequences of its dysfunction

The discovery of premotor and parietal cells known as mirror neurons in the macaque brain that fire not only when the animal is in action, but also when it observes others carrying out the same actions provides a plausible neurophysiological mechanism for a variety of important social behaviours, from imitation to empathy. Recent data also show that dysfunction of the mirror neuron system in humans might be a core deficit in autism, a socially isolating condition. Here, we review the neurophysiology of the mirror neuron system and its role in social cognition and discuss the clinical implications of mirror neuron dysfunction.

Failure to deactivate in autism: the co-constitution of self and other

A new brain imaging study demonstrates that patients with autism have a strikingly different pattern of brain activity compared with control subjects. During cognitive tasks, cortical areas known as the "default state" network--areas that have been implicated in both self-referential processing and processing of socially relevant information--typically reduce their brain activity. In patients with autism, such a reduction was not observed. This new finding indicates that a core deficit in autism might be related to the construal of a sense of self in its relationship with others and will certainly generate exciting new research on the neurobiology of autism.

The Collateral Effects of Joint Attention Training on Social Initiations, Positive Affect, Imitation, and Spontaneous Speech for Young Children with Autism

Joint attention may be a core deficit in autism which underlies the abnormal development of later emerging social-communication behaviors. Given this theory, researchers have suggested that teaching young children with autism to engage in joint attention may lead to collateral increases in other non-targeted social-communication behaviors. In this study, children with autism participated in a 10-week joint attention training program and collateral changes in non-targeted behaviors were assessed. Following participation in the intervention, positive collateral changes were observed in social initiations, positive affect, imitation, play, and spontaneous speech. Results support the hypothesis that teaching joint attention skills leads to improvement in a variety of related skills and have implications for the treatment of young children with autism.