Core Deficits In Autism Research Articles

Autism from Developmental and Neuropsychological Perspectives

In this review of the research literature on autism, we argue that the application of developmental and neuropsychological perspectives has contributed importantly to the understanding of the core deficits in autism and their underlying neural bases. The three classes of theories postulated to explain the developmental and neuropsychological deficits in autism are considered in terms of the specificity, uniqueness, and universality of these impairments in autism. Because we believe that a primary reason for our lack of understanding of the developmental trajectory in autism stems from our inability to diagnose the syndrome in the first three years of life, research approaches to early identification are discussed, as are longitudinal studies aimed at identifying later-life outcomes and their predictors. In contrast to the progress made in defining the core deficits and arriving at criteria for diagnosis, less progress has been made in identifying the causes of autism and in creating and testing interventions aimed at ameliorating the impairments of autism, possibly because these activities have been less tied to the developmental and neuropsychological models that have enlightened the investigation of core deficits.

Theory of mind abilities in young siblings of children with autism

Deficits in theory of mind (ToM), evident in most individuals with autism, have been suggested as a core deficit of autism. ToM difficulties in young siblings of children with autism (SIBS-A) compared to siblings of typically developing children (SIBS-TD) would place the former within the broad phenotype. We examined ToM's possible associations with measures of language, cognition, and daily living skills. Participants comprised 24 SIBS-A and 24 matched SIBSTD aged 4.6 years. They completed the false belief and the strange stories tasks. We also collected measures of verbal and cognitive ability and daily living skills. Non-significant differences emerged between the groups on both ToM tasks. Differences did emerge in within-group associations between ToM ability and receptive language. The conclusion is that SIBS-A show resilience in ToM abilities. Possibly, these deficits are not genetically transferred to siblings, at least as measured in laboratory-based ToM tasks.

Language, Social, and Executive Functions in High Functioning Autism: A Continuum of Performance

This study examined language and executive functions (EF) in high-functioning school-aged individuals with autism and individually matched controls. Relationships between executive, language, and social functioning were also examined. Participants with autism exhibited difficulty on measures of expressive grammar, figurative language, planning, and spatial working memory. A mixed profile of impaired and enhanced abilities was noted in set-shifting. While controls showed the typical increase in errors when shifting sets from an intra-dimensional to an extra-dimensional stimulus, this pattern was not noted in participants with autism. Relationships between EF, language, and social performance were weak to non-existent. Implications for theories of core deficit in autism and dissociable nature of the language and executive impairments in autism are discussed.

Early detection of core deficits in autism

The goal of this review of the research literature is to discuss approaches to the early detection of autism in infancy. Early detection would enable diagnoses to be made before 18 months of age rather than at 24-30 months, the age where diagnoses start to be made now. After summarizing the criteria for a deficit to be considered "core" to the disorder, the literature on research strategies used in early detection is examined. In order to guide the design of future studies, the review then turns to an overview of what is known about the processes of early social development in typically developing children that underlie the domains in which core deficits are manifested in young children with autism. The social domains covered in the review are those that show development in typically developing infants below 18 months of age: dyadic interaction and imitation; emotion discrimination; and attachment. The review concludes that all of these areas are worthy of investigation in young children, particularly those at higher risk of showing some of the core deficits of autism such as the infant siblings of children with autism.

Is Autism a Preventable Disorder of Verbal Behavior? A Response to Five Commentaries

This paper presents a response to five commentaries on our article An Analysis of Autism as a Contingency-Shaped Disorder of Verbal Behavior (Drash & Tudor, 2004). One of the principal objectives of that article is to provide the behavior analysis community and the autism community with a conceptual basis for analyzing autism as a behavioral disorder rather than a neurological disorder. This analysis provides a logical and testable behavioral answer to the question of the etiology of autism, a question that has baffled scientists and researchers for more than half a century. Elements of the original article with which reviewers expressed concern include: need for more data, need for greater emphasis on neurological and epidemiological factors in autism, the relative importance of verbal behavior as a core deficit of autism, and disruptive and avoidant behavior as a primary variable in the etiology of autism. We provide a behavioral response to each of these concerns. We also show how our analysis will provide a conceptual foundation for behavior analysis to begin developing urgently needed programs for prevention and earlier intervention in autism.

Naltrexone and Communication Skills in Young Children With Autism

To evaluate the effect of naltrexone on communication skills of young children with autism. Twenty-four children with autism, 3.0 to 8.3 years old (mean 5.1) who were living at home and attending appropriate school programs, participated in a randomized, double-blind, placebo-controlled, crossover trial. Naltrexone, 1.0 mg/kg, or placebo was administered daily for 2 weeks. Communication was evaluated from videotaped samples of seminaturalistic parent-child interaction. Child and parent language were assessed using similar measures. In this heterogeneous sample, the median number of words the child produced on placebo was 9.5 (range 0-124). The median proportion of utterances with echolalia was 0.16. No differences were found between the naltrexone and placebo conditions in any of the measures of children or parents' communication. Significant correlations were found between the child's number of words and developmental quotient (Spearman rho = 0.58, p = .003) and between the child's and parent's number of words (rho = 0.55, p = .005). Previous studies showed that naltrexone was associated with modest reduction in hyperactivity and restlessness in this group of children with autism. In this short-term study, the medication did not lead to improvement in communication, a core deficit of autism.

Current research findings on childhood autism.

To review the main areas of current research findings regarding the core deficits in autism and the implications of these findings for the practicing clinician. Behavioural, cognitive, emotional and neurophysiological aspects are covered with an emphasis on the importance of methodology. The implication of these findings for the treatment of autism is discussed. Autism can teach us how we learn about emotions and the possibility of sensitive periods of development.

How specific is specific language impairment? On problems of delineation and classification

In this paper, the problems of defining specific language impairment in children are addressed. In particular, the borderline between specific language impairment and handicaps involving disorders of pragmatics and/or cognition are scrutinized. The delineation between specific language impairment on the one hand, and language impairment concomitant with other handicaps has, to some extent, been arbitrary and unfortunate. One example of this dilemma is represented by children with semantic-pragmatic disorders, a subgroup within specific language impairment. Some authors have hypothesized a kinship between semantic-pragmatic disorder and autism. Most researchers specialized in autism seem to consider the problem of creating and handling metarepresentations as the core deficit in autism. Whether children with a semantic-pragmatic disorder also exhibit such problems is still an open question. A linguistic/conceptual basis for semantic-pragmatic disorder is suggested by the authors who also present suggestions...

Verbal problem solving in high functioning autistic individuals

The verbal problem-solving and abstract reasoning ability of 25 high-functioning autistic individuals ages 11 to 41 was compared with normal controls individually matched on age, gender, race, IQ, and educational level. The Twenty Questions Procedure was administered using a grid of 42 common objects. Time to complete the task, number of correct solutions, and number and type of questions asked were analyzed. Results indicated that controls were more often successful in achieving solutions, and in formulating constraint seeking questions that conceptually grouped, ordered, and sorted the objects. In contrast, the autistics relied primarily on guessing. Findings are consistent with prior studies reporting a core deficit in autism involving abstract reasoning ability.

New perspectives in autism. Part 2: the differential diagnosis and neurobiology of autism

The clinical spectrum of autism spans a broad range of functions, but the core symptoms remain the same regardless of the intelligence of the child: the autistic type of social deficit that ranges from a lack of inclination to relate to extreme difficulty with the mechanics of social interactions, a global communication deficit that involves both verbal and nonverbal modes, and a severe cognitive deficit involving concept formation (abstraction) that is combined with an exceptional memory for factual information. These symptoms may vary dramatically in severity, but the basic deficits are identifiable regardless of IQ. Under-recognition of autism is a major problem at all IQs, but especially in patients with IQs above 50. No drugs have been found to significantly improve the core deficits in autism. Antipsychotics should be avoided except for short-term use. Anti-depressants, anxiolytics, and anticonvulsants are important in the treatment of depression, affective modulation, situation-related stress, and seizures. Intensive social skills training is assuming a prominent role in behavior modification programs, and success with higher-functioning autistic children suggests that outcome can be improved by intensive training. The neurobiology of autism has also undergone dramatic changes. The psychogenic theories of etiology have been completely invalidated. Autism is now considered to be a neurological disorder resulting from an error in brain development. The precise location and nature of this deficit are still being actively debated and investigated. One theory emphasizes a dysfunction of the limbic system that results in an impairment in the acquisition of information. A second theory proposes a primary role for dysfunction of the cortical association network responsible for the processing of information.