The strength and generality of stimulus over-selectivity in simultaneous discrimination procedures

Stimulus over-selectivity refers to behavior being controlled by one element of the environment at the expense of other equally salient aspects of the environment. This is a common problem for many individuals, including those with autism spectrum disorders, and learning difficulties, and presents a considerable problem for information processing in many important situations involving complex cues and environments. Three experiments explored the strength and generality of the over-selectivity effect in non-clinical adults undertaking a cognitively demanding task, by training and testing participants on a two-component trial-and-error discrimination learning task. The over-selectivity effect was found in a variety of test conditions, including when the comparison test stimulus was neutral (Experiment 1), novel (Experiment 2), neutral with no conditioning history (Experiment 3), or when punished during training (Experiments 1, 2 and 3). Such results provide ubiquity to the phenomenon, making it important to investigate further.     

A model of communicative perspective-taking for typical and atypical populations of children

Successful communication requires that individuals attend to the perspective of their conversational partners and use this information to modify their behavior accordingly. This paper presents a framework by which to understand children’s communicative perspective-taking skills and, within this framework, outlines three routes by which children’s communicative perspective-taking performance can be disrupted. First, children may have difficulty in communicative contexts due to deficits in mentalizing ability whereby they are unable to appreciate another’s perspective. Second, children may have intact mentalizing abilities but do not have the cognitive skills to support the use of this information when generating communicative behaviors. Third, decreased social exposure may lead to exacerbated deficits in either mentalizing ability or the use of mentalistic information within communicative contexts. Patterns within both typical and atypical populations (i.e., autism, ADHD, and mood disorders) are reviewed.     

自闭症谱系障碍个体的社会动机缺陷

自闭症谱系障碍(ASD)是一种源于儿童期的神经发育障碍, 社会交往障碍是其核心特征, 与社会动机缺陷密切相关。社会动机是引导个体社会行为的强大动力, 主要表现为社会定向、社会奖赏和社会维持。现有研究表明, ASD个体的社会动机发展存在缺陷, 他们对社会刺激的注意偏向减少, 不能主动寻求和体会社会互动带来的快乐, 且缺乏维持社会关系的行为策略等。然而, 相关研究结果受到个体特征、环境和实验设计等因素的影响。研究者未来应综合考虑这些影响因素, 加强对ASD个体社会动机理论的整合研究, 以便全面系统地了解ASD个体的社会动机缺陷。     

Randomized controlled trial of parental responsiveness intervention for toddlers at high risk for autism

This study tested the effects of a parent-mediated intervention on parental responsiveness with their toddlers at high risk for an autism spectrum disorder (ASD).Participants included caregivers and their 66 toddlers at high risk for ASD. Caregivers were randomized to 12 sessions of an individualized parent education intervention aimed at improving parental responsiveness or to a monitoring control group involving 4 sessions of behavioral support. Parental responsiveness and child outcomes were measured at three time points: at beginning and end of the 3-month treatment and at 12-months post-study entry. Parental responsiveness improved significantly in the treatment group but not the control group. However, parental responsiveness was not fully maintained at follow up. There were no treatment effects on child outcomes of joint attention or language. Children in both groups made significant developmental gains in cognition and language skills over one year. These results support parental responsiveness as an important intervention target given its general association with child outcomes in the extant literature; however, additional supports are likely needed to fully maintain the treatment effect and to affect child outcomes.     

High cognitive sensitivity to activational effects of testosterone in parents of offspring with autism spectrum disorders

The existence of mild forms of autistic-like characteristics in parents of children with autism spectrum disorders (ASDs) has been defined as a broader autistic phenotype (BAP). Excessive prenatal exposure to testosterone (T) seems to play a role in its development. The aims of this study were to characterize whether ASD parents show masculinized brains or high T prenatal exposure compared to a normative population, using cognitive questionnaires, and also to examine the T level changes in response to different cognitive tasks. ASD parents were found to present higher autistic and lower empathic trait scores than controls. They also have higher T levels and magnitude of T response to cognitive tasks. Specific correlation patterns between masculinized brain types and T levels were observed only in ASD parents. Thus, it seems that first-degree relatives of people with ASD have high T levels during task performance, which, in turn, produce slight cognitive masculinization. Our findings should be considered for understanding the role of androgens in the etiology of ASD. Nevertheless, the masculinization parameters described throughout the study are subtle and require further analysis.     

Neural processing of intentional biological motion in unaffected siblings of children with autism spectrum disorder: An fMRI study

Despite often showing behaviorally typical levels of social cognitive ability, unaffected siblings of children with autism spectrum disorder have been found to show similar functional and morphological deficits within brain regions associated with social processing. They have also been reported to show increased activation to biological motion in these same regions, such as the posterior superior temporal sulcus (pSTS), relative to both children with autism and control children. It has been suggested that this increased activation may represent a compensatory reorganization of these regions as a result of the highly heritable genetic influence of autism. However, the response patterns of unaffected siblings in the domain of action perception are unstudied, and the phenomenon of compensatory activation has not yet been replicated. The present study used functional magnetic resonance imaging to determine the neural responses to intentional biological actions in 22 siblings of children with autism and 22 matched controls. The presented actions were either congruent or incongruent with the actor’s emotional cue. Prior studies reported that typically developing children and adults, but not children with autism, show increased activation to incongruent actions (relative to congruent), within the pSTS and dorsolateral prefrontal cortex. We report that unaffected siblings did not show a compensatory response, or a preference for incongruent over congruent trials, in any brain region. Moreover, interaction analyses revealed a sub-region of the pSTS in which control children showed an incongruency preference to a significantly greater degree than siblings, which suggests a localized deficit in siblings. A sample of children with autism also did not show differential activation in the pSTS, providing further evidence that it is an area of selective disruption in children with autism and siblings. While reduced activation to both conditions was unique to the autism sample, lack of differentiation to incongruent and congruent intentional actions was common to both children with ASD and unaffected siblings.     

From early markers to neuro-developmental mechanisms of autism

A fast growing field, the study of infants at risk because of having an older sibling with autism (i.e. infant sibs) aims to identify the earliest signs of this disorder, which would allow for earlier diagnosis and intervention. More importantly, we argue, these studies offer the opportunity to validate existing neuro-developmental models of autism against experimental evidence. Although autism is mainly seen as a disorder of social interaction and communication, emerging early markers do not exclusively reflect impairments of the “social brain”. Evidence for atypical development of sensory and attentional systems highlight the need to move away from localized deficits to models suggesting brain-wide involvement in autism pathology. We discuss the implications infant sibs findings have for future work into the biology of autism and the development of interventions.