Sensitivity to the prototype in children with high-functioning autism spectrum disorder: An example of Bayesian cognitive psychometrics

We present a case study of hierarchical Bayesian explanatory cognitive psychometrics, examining information processing characteristics of individuals with high-functioning autism spectrum disorder (HFASD). On the basis of previously published data, we compare the classification behavior of a group of children with HFASD with that of typically developing (TD) controls using a computational model of categorization. The parameters in the model reflect characteristics of information processing that are theoretically related to HFASD. Because we expect individual differences in the model’s parameters, as well as differences between HFASD and TD children, we use a hierarchical explanatory approach. A first analysis suggests that children with HFASD are less sensitive to the prototype. A second analysis, involving a mixture component, reveals that the computational model is not appropriate for a subgroup of participants, which implies parameter estimates are not informative for these children. Focusing only on the children for whom the prototype model is appropriate, no clear difference in sensitivity between HFASD and TD children is inferred.     

A connectionist model of category learning by individuals with high-functioning autism spectrum disorder

Individuals with autism spectrum disorder (ASD) show atypical patterns of learning and generalization. We explored the possible impacts of autism-related neural abnormalities on perceptual category learning using a neural network model of visual cortical processing. When applied to experiments in which children or adults were trained to classify complex two-dimensional images, the model can account for atypical patterns of perceptual generalization. This is only possible, however, when individual differences in learning are taken into account. In particular, analyses performed with a self-organizing map suggested that individuals with high-functioning ASD show two distinct generalization patterns: one that is comparable to typical patterns, and a second in which there is almost no generalization. The model leads to novel predictions about how individuals will generalize when trained with simplified input sets and can explain why some researchers have failed to detect learning or generalization deficits in prior studies of category learning by individuals with autism. On the basis of these simulations, we propose that deficits in basic neural plasticity mechanisms may be sufficient to account for the atypical patterns of perceptual category learning and generalization associated with autism, but they do not account for why only a subset of individuals with autism would show such deficits. If variations in performance across subgroups reflect heterogeneous neural abnormalities, then future behavioral and neuroimaging studies of individuals with ASD will need to account for such disparities.     

Task-switching abilities in children with autism spectrum disorder

Task-switching performance is often used as a measure of executive control functions. Various task-switching studies in children with autism spectrum disorder (ASD) found, in contrast to expectations, no impairments in cognitive flexibility. Here, we studied whether the role of memory for arbitrary task rules can explain these findings, and how studying rule memory can help to generally better understand executive control. We designed a novel task-switching paradigm to separate cognitive flexibility from demand on memory for arbitrary rules, and we compared 19 children with ASD (9 to 16 years old) with an age- and IQ-matched control group. Children with ASD had increased difficulty with task switching only when memorizing arbitrary rules was required. When no arbitrary rules needed to be memorized, they performed accurately and quickly. Nevertheless, they showed less distraction from task-irrelevant stimulus features, suggesting that they represented tasks differently from the children in the comparison group. We conclude that children with ASD have a weaker capacity of forming rule representations, which only leads to performance impairment when they need to memorize arbitrary rules. Further, executive control impairments in ASD seem more complex than hitherto hypothesized due to mutual interactions between memory demand and task representations.     

Teaching children with autism spectrum disorder to tact olfactory stimuli

Research on tact acquisition by children with autism spectrum disorder (ASD) has often focused on teaching participants to tact visual stimuli. It is important to evaluate procedures for teaching tacts of nonvisual stimuli (e.g., olfactory, tactile). The purpose of the current study was to extend the literature on secondary target instruction and tact training by evaluating the effects of a discrete‐trial instruction procedure involving (a) echoic prompts, a constant prompt delay, and error correction for primary targets; (b) inclusion of secondary target stimuli in the consequent portion of learning trials; and (c) multiple exemplar training on the acquisition of item tacts of olfactory stimuli, emergence of category tacts of olfactory stimuli, generalization of category tacts, and emergence of category matching, with three children diagnosed with ASD. Results showed that all participants learned the item and category tacts following teaching, participants demonstrated generalization across category tacts, and category matching emerged for all participants.     

Caregiver-implemented toilet training procedures for children with autism spectrum disorder

Children with Autism Spectrum Disorder often exhibit deficits in daily living skills, including toileting skills. Previous studies have evaluated components of common toilet training practices, including differential reinforcement, sit schedules, fluid loading, underwear, and wet alarms. The purpose of this study was to replicate and extend previous work by delivering all coaching remotely. Three caregiver-child dyads participated in this study. A researcher coached caregivers on the implementation of the protocol using a modified behavioral skills training approach via telehealth. Caregivers submitted daily toileting data and weekly audio recordings for treatment integrity checks. The sit schedule fading was individualized to meet the needs and preferences of each family. All caregivers implemented the protocol with high integrity. Two participants met the mastery criteria at the 90-min sit schedule and maintained performance at the 1- and 6-week maintenance follow up probes. The third participant, despite an interruption of treatment, also reached mastery.     

Semantic richness and word learning in children with autism spectrum disorder

Semantically rich learning contexts facilitate semantic, phonological, and articulatory aspects of word learning in children with typical development (TD). However, because children with autism spectrum disorder (ASD) show differences at each of these processing levels, it is unclear whether they will benefit from semantic cues in the same manner as their typical peers. The goal of this study was to track how the inclusion of rich, sparse, or no semantic cues influences semantic, phonological, and articulatory aspects of word learning in children with ASD and TD over time. Twenty‐four school‐aged children (12 in each group), matched on expressive vocabulary, participated in an extended word learning paradigm. Performance on five measures of learning (referent identification, confrontation naming, defining, phonetic accuracy, and speech motor stability) were tracked across three sessions approximately one week apart to assess the influence of semantic richness on extended learning. Results indicate that children with ASD benefit from semantically rich learning contexts similarly to their peers with TD; however, one key difference between the two groups emerged – the children with ASD showed heightened shifts in speech motor stability. These findings offer insights into common learning mechanisms in children with ASD and TD, as well as pointing to a potentially distinct speech motor learning trajectory in children with ASD, providing a window into the emergence of stereotypic vocalizations in these children.     

Reinforcing the prospective remembering of children with autism spectrum disorder

Prospective memory is remembering to carry out a behavior on a particular occasion or at a specific time in the future. This form of remembering is critical for the daily functioning of children with autism spectrum disorder (ASD) and their functional independence from caregivers. We used a single-subject design to investigate whether reinforcement increased the accuracy of prospective remembering in the context of a computerized board game, Virtual Week, of four 6- to 7-year-old children diagnosed with ASD. Reinforcement increased accuracy for all participants compared to baseline performance and effects were maintained after reinforcement was discontinued for three of four children. This is the first study of which we are aware to use a reinforcement-based behavioral intervention to improve the prospective remembering of children with ASD. Limitations and areas for future research are discussed.     

Teaching children with autism spectrum disorder to tact auditory stimuli

Studies on teaching tacts to individuals with autism spectrum disorder (ASD) have primarily focused on visual stimuli, despite published clinical recommendations to teach tacts of stimuli in other sensory domains as well. In the current study, two children with ASD were taught to tact auditory stimuli under two stimulus‐presentation arrangements: isolated (auditory stimuli presented without visual cues) and compound (auditory stimuli presented with visual cues). Results indicate that compound stimulus presentation was a more effective teaching procedure, but that it interfered with prior object‐name tacts. A modified compound arrangement in which object‐name tact trials were interspersed with auditory‐stimulus trials mitigated this interference.     

Choice for reinforced behavioral variability in children with autism spectrum disorder

Although individuals with autism spectrum disorder (ASD) tend to behave repetitively, certain reinforcement contingencies (e.g., lag schedules) can be used to increase behavioral variability. In a lag schedule, reinforcers only follow responses that differ from recent responses. The present study was designed to promote variable play behavior in preschoolers with ASD interacting with playsets and figurines and to assess preference for variability and repetition contingencies. Data have shown a preference for variability in pigeons and college students, but this effect has not been explored in clinical populations. In this experiment, preschoolers with ASD were taught to discriminate between variability and repetition contingencies. Only play behaviors that met a lag schedule were reinforced in the presence of one color, and only repetitive behaviors were reinforced in the presence of another. After differential performance was established, participants experienced a concurrent chains schedule. Participants chose between the colors taught in training and then completed a play session with the selected contingency. One participant selected variability and repetition equally. The other participants showed a slight preference for variability. These results indicate that some individuals with ASD may play repetitively, not because they prefer repetition, but because they require additional teaching to play variably.     

Sylvian fissure and parietal anatomy in children with autism spectrum disorder

Autism spectrum disorder (ASD) is characterized by deficits in social functioning and language and communication, with restricted interests or stereotyped behaviors. Anatomical differences have been found in the parietal cortex in children with ASD, but parietal subregions and associations between Sylvian fissure (SF) and parietal anatomy have not been explored. In this study, SF length and anterior and posterior parietal volumes were measured on MRI in 30 right-handed boys with ASD and 30 right-handed typically developing boys (7-14 years), matched on age and non-verbal IQ. There was leftward SF and anterior parietal asymmetry, and rightward posterior parietal asymmetry, across groups. There were associations between SF and parietal asymmetries, with slight group differences. Typical SF asymmetry was associated with typical anterior and posterior parietal asymmetry, in both groups. In the atypical SF asymmetry group, controls had atypical parietal asymmetry, whereas in ASD there were more equal numbers of individuals with typical as atypical anterior parietal asymmetry. We did not find significant anatomical-behavioral associations. Our findings of more individuals in the ASD group having a dissociation between cortical asymmetries warrants further investigation of these subgroups and emphasizes the importance of investigating anatomical relationships in addition to group differences in individual regions.     

Atypical shape bias and categorization in autism: Evidence from children and computational simulations

The shape bias, a preference for mapping new word labels onto the shape rather than the color or texture of referents, has been postulated as a word‐learning mechanism. Previous research has shown deficits in the shape bias in children with autism even though they acquire sizeable lexicons. While previous explanations have suggested the atypical use of color for label extension in individuals with autism, we hypothesize an atypical mapping of novel labels to novel objects, regardless of the physical properties of the objects. In Experiment 1, we demonstrate this phenomenon in some individuals with autism, but the novelty of objects only partially explains their lack of shape bias. In a second experiment, we present a computational model that provides a developmental account of the shape bias in typically developing children and in those with autism. This model is based on theories of neurological dysfunctions in autism, and it integrates theoretical and empirical findings in the literature of categorization, word learning, and the shape bias. The model replicates the pattern of results of our first experiment and shows how individuals with autism are more likely to categorize experimental objects together on the basis of their novelty. It also provides insights into possible mechanisms by which children with autism learn new words, and why their word referents may be idiosyncratic. Our model highlights a developmental approach to autism that emphasizes deficient representations of categories underlying an impaired shape bias.     

MMPI-2 personality profiles of high-functioning adults with autism spectrum disorders

The Minnesota Multiphasic Personality Inventory-Second Edition was administered to 20 adults with autism spectrum disorders (ASD) who fell in the average to above average range of intelligence and 24 age-, intelligence-, and gender-matched college students. Large group differences, with the ASD group scoring higher, were found on the L validity scale, Clinical Scales 2 (D) and 0 (Si), Content scale Social Discomfort (SOD), Supplementary scale Repression (R), and Personality Psychopathology Five (PSY-5) scale INTR (Introversion). The proportion of ASD adults scoring in the clinical range on these scales was between 25% and 35%. High scores on these scales are consistent with the clinical picture of Asperger syndrome and high-functioning autism in adulthood. Future directions and implications for identifying adults in need of a specialized autism assessment are discussed.     

Processing of musical structure by high-functioning adolescents with autism spectrum disorders

Enhanced pitch perception and memory have been cited as evidence of a local processing bias in autism spectrum disorders (ASD). This bias is argued to account for enhanced perceptual functioning (Mottron &; Burack, 2001 Mottron, L. and Burack, J. A. 2001. “Enhanced perceptual functioning in the development of autism”. In The development of autism: Perspectives from theory to research, Edited by: Burack, J. A., Charman, T., Yirmiya, N. and Zelazo, P. R. 131–147. Mahwah, NJ: Lawrence Erlbaum.  [Google Scholar]; Mottron, Dawson, Soulières, Hubert, &; Burack, 2006 Mottron, L., Dawson, M., Soulières, I., Hubert, B. and Burack, J. 2006. Enhanced perceptual functioning in autism: An update, and eight principles of autistic perception. Journal of Autism and Developmental Disorders, 36(1): 27–43. doi:10.1007/s10803-005-0040-7[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]) and central coherence theories of ASD (Frith, 1989 Frith, U. 1989. Autism: Explaining the enigma, Oxford: United Kingdom: Blackwell.  [Google Scholar]; Happé &; Frith, 2006 Happé, F. and Frith, U. 2006. The weak coherence account: Detail-focused cognitive style in autism spectrum disorders. Journal of Autism and Developmental Disorders, 36(1): 5–25. doi:10.1007/s10803-005-0039-0[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). A local processing bias confers a different cognitive style to individuals with ASD (Happé, 1999 Happé, F. 1999. Autism: Cognitive deficit or cognitive style?. Trends in Cognitive Sciences, 3(6): 216–222. doi:10.1016/S1364-6613(99)01318-2[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]), which accounts in part for their good visuospatial and visuoconstructive skills. Here, we present analogues in the auditory domain, audiotemporal or audioconstructive processing, which we assess using a novel experimental task: a musical puzzle. This task evaluates the ability of individuals with ASD to process temporal sequences of musical events as well as various elements of musical structure and thus indexes their ability to employ a global processing style. Musical structures created and replicated by children and adolescents with ASD (10–19 years old) and typically developing children and adolescents (7–17 years old) were found to be similar in global coherence. Presenting a musical template for reference increased accuracy equally for both groups, with performance associated to performance IQ and short-term auditory memory. The overall pattern of performance was similar for both groups; some puzzles were easier than others and this was the case for both groups. Task performance was further found to be correlated with the ability to perceive musical emotions, more so for typically developing participants. Findings are discussed in light of the empathizing-systemizing theory of ASD (Baron-Cohen, 2009 Baron-Cohen, S. 2009. Autism: The Empathizing-Systemizing (E-S) Theory. Annals of the New York Academy of Sciences, 1156: 68–80. doi:10.1111/j.1749-6632.2009.04467.x[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]) and the importance of describing the strengths of individuals with ASD (Happé, 1999 Happé, F. 1999. Autism: Cognitive deficit or cognitive style?. Trends in Cognitive Sciences, 3(6): 216–222. doi:10.1016/S1364-6613(99)01318-2[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]; Heaton, 2009 Heaton, P. 2009. Assessing musical skills in autistic children who are not savants. Philosophical Transactions of the Royal Society Biological Sciences, 364: 1443–1447. doi:10.1098/rstb.2008.0327[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]).     

A replication of preference displacement research in children with autism spectrum disorder

The purpose of this paper was to replicate previous research on preference displacement with edible and leisure stimuli. In the present study, the experimenters evaluated preference displacement in 25 children with autism spectrum disorder using combined multiple stimulus without replacement preference assessments that consisted of highly preferred edible and leisure stimuli. In addition, the experimenters used a block randomization procedure to evaluate if assessment order influenced displacement outcomes. The experimenters observed patterns of complete displacement by edible stimuli for four participants and complete displacement by leisure stimuli for two participants; assessment order did not influence outcomes. The results and implications are discussed.     

Toward establishing a qualifying autoclitic repertoire in children with autism spectrum disorder

Autoclitics are secondary verbal operants that are controlled by a feature of the conditions that occasion or evoke a primary verbal operant such as a tact or mand. Qualifying autoclitics extend, negate, or assert a speaker's primary verbal response and modify the intensity or direction of the listener's behavior. Howard and Rice (1988) established autoclitics that indicated weak stimulus control (e.g., “like a [primary tact]”) with four neurotypical preschool children. However, generalization to newly acquired tacts was limited. In Experiment 1, we addressed similar behavior as in Howard and Rice but with autistic children while using simultaneous teaching procedures, and we observed generalization across sets and with newly acquired tacts. In Experiment 2, we evaluated the effects of multiple-exemplar training on generalization of autoclitics across sets of naturalistic stimuli. Across participants, gradual increases in the frequency of autoclitics occurred with untaught stimuli after teaching with one or more sets.     

An experimental demonstration of AAB renewal in children with autism spectrum disorder

Operant renewal is a return of extinguished behavior due to changes in contextual stimuli that control the occurrence or nonoccurrence of a response. Well‐established in classical conditioning and operant research, renewal presents itself in three forms—ABA, ABC, and AAB—and poses threats to treatment maintenance where extinction procedures are utilized. As AAB renewal may be less likely to occur than ABA or ABC renewal, the current study sought to determine if AAB renewal would occur with three participants with Autism Spectrum Disorder who were taught a simple lever pull response. Results showed that lever pulls increased for two of three participants when we introduced novel stimuli (i.e., a light and a buzzer) to alter the contextual environment after extinction. These findings suggest that AAB renewal may account for some instances of response recovery after extinction and that the procedure of this study may be beneficial to the further study of renewal and the variables that affect its occurrence within a translational model.     

Response inhibition and immediate arousal in children with high-functioning autism.

The current study compared high-functioning children with autism (HFA) and a peer control group on an immediate arousal task measuring response inhibition. In one condition go stimuli were presented whereas in another condition a tone preceded the go stimulus. The tone caused an immediate arousal effect, which resulted in a reaction time decrease and an error rate increase. It was expected that children with HFA would produce a higher error rate in comparison with normal peers, since they might be less able to suppress immediate arousal. However, the HFA group outperformed the control group, indicating neither arousal regulation deficit nor response inhibition deficit.     

White matter integrity and pictorial reasoning in high-functioning children with autism

The current study investigated the neurobiological role of white matter in visuospatial versus linguistic processing abilities in autism using diffusion tensor imaging. We examined differences in white matter integrity between high-functioning children with autism (HFA) and typically developing controls (CTRL), in relation to the groups’ response times (RT) on a pictorial reasoning task under three conditions: visuospatial, V, semantic, S, and V + S, a hybrid condition allowing language use to facilitate visuospatial transformations.     

孤独症儿童动作发展障碍的神经机制

动作发展障碍(Developmental motor disorders)是孤独症谱系障碍的常见特征。通过系统回顾孤独症儿童动作发展障碍的神经科学研究, 发现γ-氨基丁酸和5-羟色胺浓度的改变及γ-氨基丁酸相关蛋白和Shank蛋白的表达异常不仅会损害中枢神经系统的发育, 而且还能导致突触兴奋性与抑制性失衡, 进而改变孤独症儿童小脑和大脑皮层运动区的功能连接。孤独症儿童小脑、基底神经节和胼胝体结构的改变对全脑的连通性产生了负面影响。神经生化机制和脑结构的异常共同导致了脑功能的异常, 最终造成孤独症儿童的动作发展障碍。此外, 动作发展障碍与孤独症核心症状共同的神经基础主要包括镜像神经元系统紊乱, 丘脑、基底神经节和小脑异常以及SLC7A5和PTEN 基因突变。未来研究需要关注与运动密切相关的其他神经递质, 如乙酰胆碱和多巴胺; 探索动作发展障碍神经网络的动态机制及其形成; 剖析该障碍的神经机制和自闭症核心症状神经机制的相互作用。     

Treating food selectivity as resistance to change in children with autism spectrum disorder

Change-resistant behavior, such as rigid and selective food consumption, is a core symptom of autism that can have significant negative consequences for the child (Flygare Wallén et al., 2018; Levy et al., 2019). In the current study, we used a matching-law-based intervention (Fisher et al., 2019) to treat the change-resistant feeding behavior of 7 young children with autism. The feeder gave the participant a choice between a change-resistant and an alternative food during free- and asymmetrical-choice conditions. Alternative-food consumption increased for 2 participants during asymmetrical choice when the feeder provided a preferred item for consuming the alternative food and no programmed consequence for consuming the change-resistant food. Alternative-food consumption increased for the other 5 participants after the feeder exposed at least 1 food to single choice in which the feeder guided the participant to put the bite of alternative food in his or her mouth if he or she did not do so within 8 s of presentation. Effects of the single-choice contingencies maintained during reversals and generalized to other alternative foods the feeder did not expose to single choice. These results are important because participants consumed alternative foods even when their change-resistant foods were present, which is similar to typical mealtime contexts in which children have choices among foods.