Children with ASD can use gaze in support of word recognition and learning

Reduced Implicit but not Explicit Knowledge of Cross-Situational Statistical Learning in Developmental Dyslexia

Although statistical learning (SL) has been studied extensively in developmental dyslexia (DD), less attention has been paid to other fundamental challenges in language acquisition, such as cross-situational word learning. Such investigation is important for determining whether and how SL processes are affected in DD at the word level. In this study, typically developed (TD) adults and young adults with DD were exposed to a set of trials that contained multiple spoken words and multiple pictures of individual objects, with no information about word-referent correspondences provided within a trial. Nonetheless, cross-trial statistical relations could be exploited to learn word-referent mappings. The degree of within-trial reference uncertainty and the novelty of to-be-learned objects (novel or familiar) were varied under different learning conditions. The results show that across all conditions, young adults with DD were significantly impaired in their ability to exploit cross-trial regularities in co-occurring visual-auditory streams to discover word-referent mappings. Observed impairments were most pronounced when within-trial reference uncertainty was the highest. Subjective measures of knowledge awareness revealed greater development of implicit but not explicit knowledge in the TD group than in the DD group. Together, these findings suggest that the SL deficit in DD affects fundamental language learning challenges at the word level and points to greater reliance on explicit processes due to impaired implicit associative learning among individuals with DD. Such a deficit is likely to influence spoken language acquisition, and in turn affect literacy skills, in people with DD.

How do Autistic and Neurotypical Children's Interests Influence their Accuracy During Novel Word Learning?

Word learning depends on attention - children must focus on the right things at the right times. However, autistic children often display restricted interests, limiting their intake of stimuli during word learning. This study investigates how category interests influence word learning in autism and neurotypical development. Autistic and neurotypical children matched on receptive vocabulary used a touch-screen computer to learn novel words associated with animals (high-interest stimuli) and objects (neutral-interest stimuli) via fast mapping. Response accuracy and speed were examined at referent selection, 5-minute retention, and 24-hour retention. Both groups identified meanings of novel words associated with unfamiliar animals and objects via mutual exclusivity with comparable accuracy. After 5 minutes, autistic children retained animal names with greater accuracy than neurotypical children. Autistic children showed a greater increase in their accuracy between 5-minute and 24-hour retention and outperformed neurotypical children across conditions after a night's sleep. Across groups, 24-hour retention was predicted by number of target word repetitions heard at referent selection, indicating a relationship between fast mapping input and retention. However, autistic children were slower to respond correctly, particularly in the animal condition. For autistic children, superior word learning associated with high-interest stimuli was relatively short-term, as sleep appeared to consolidate their memory representations for neutral-interest stimuli. Although these results demonstrate that fundamental word learning mechanisms are not atypical in autism, slower response times may signal a speed-accuracy trade-off that could have implications for naturalistic language acquisition. Our findings also indicate favourable environmental conditions to scaffold word learning.

Combining statistics: the role of phonotactics on cross-situational word learning

Language learners can rely on phonological and semantic information to learn novel words. Using a cross-situational word learning paradigm, we explored the role of phonotactic probabilities on word learning in ambiguous contexts. Brazilian-Portuguese speaking adults (N = 30) were exposed to two sets of word-object pairs. Words from one set of labels had slightly higher phonotactic probabilities than words from the other set. By tracking co-occurrences of words and objects, participants were able to learn word-object mappings similarly across both sets. Our findings contrast with studies showing a facilitative effect of phonotactic probability on word learning in non-ambiguous contexts.

Language development, reading and word learning in Autism Spectrum Disorder (ASD): a review on eye tracking studies

Objectives: The purpose of this article is to review research that has been conducted over the past five years on language development, reading skills and word learning with the use of the eye tracking machine as regards the population with autism spectrum disorder (ASD) in comparison to typically developed population. Materials and methods: A combination of relevant terms from Google Scholar, Research Gate and PsychINFO databases was used and as a result 24 studies emerged. The total number of studies that met the inclusion criteria was 21. Results: Studies focusing on the language development of people with ASD have presented significant findings regarding vocabulary processing and the preferential focus on specific stimuli (images, audio) over a wide range of ages that in some cases have not been investigated until then. Furthermore, studies on reading have found that adults with ASD showed a strong preference for images and symbols over texts, longer reading time and performances similar to the typical population in vocabulary processing. Studies on word learning demonstrated that adults with ASD are able to rely on gaze cues in order to learn a new word and they have the ability to use syntactic bootstrapping. For preschool and early school-aged children with ASD the results showed that they are capable of cross-situational learning. Conclusions: This review provides information on the effectiveness of the eye tracking method as a tool that can contribute to the identification of deficits in language processing on the part of individuals with ASD from early childhood to adulthood, and more specifically as regards the domains of language development, reading and word learning.

Visual perceptual salience and novel referent selection in children with and without autism spectrum disorder

BACKGROUND & AIMS

Many young children with autism spectrum disorder (ASD) demonstrate striking delays in early vocabulary development. Experimental studies that teach the meanings of novel nonwords can determine the effects of linguistic and attentional factors. One factor that may affect novel referent selection in children with ASD is visual perceptual salience-how interesting (i.e., striking) stimuli are on the basis of their visual properties. The goal of the current study was to determine how the perceptual salience of objects affected novel referent selection in children with ASD and children who are typically developing (TD) of similar ages (mean age 3-4 years).

METHODS

Using a screen-based experimental paradigm, children were taught the names of four unfamiliar objects: two high-salience objects and two low-salience objects. Their comprehension of the novel words was assessed in low-difficulty and high-difficulty trials. Gaze location was determined from video by trained research assistants.

RESULTS

Contrary to initial predictions, findings indicated that high perceptual salience disrupted novel referent selection in the children with ASD but facilitated attention to the target object in age-matched TD peers. The children with ASD showed no significant evidence of successful novel referent selection in the high-difficulty trials. Exploratory reaction time analyses suggested that the children with autism showed "stickier" attention-had more difficulty disengaging (i.e., looking away)-from high-salience distracter images than low-salience distracter images, even though the two images were balanced in salience for any given test trial.

CONCLUSIONS AND CLINICAL IMPLICATIONS

These findings add to growing evidence that high perceptual salience has the potential to disrupt novel referent selection in children with ASD. These results underscore the complexity of novel referent selection and highlight the importance of taking the immediate testing context into account. In particular, it is important to acknowledge that screen-based assessments and screen-based learning activities used with children with ASD are not immune to the effects of lower level visual features, such as perceptual salience.

Brain mRNA Expression Associated with Cortical Volume Alterations in Autism Spectrum Disorder

Numerous studies report abnormal cerebral cortex volume (CCV) in autism spectrum disorder (ASD); however, genes related to CCV abnormalities in ASD remain largely unknown. Here, we identify genes associated with CCV alterations in ASD by performing spatial correlations between the gene expression of 6 donated brains and neuroimaging data from 1,404 ASD patients and 1,499 controls. Based on spatial correlations between gene expression and CCV differences from two independent meta-analyses and between gene expression and individual CCV distributions of 404 patients and 496 controls, we identify 417 genes associated with both CCV differences and individual CCV distributions. These genes are enriched for genetic association signals and genes downregulated in the ASD post-mortem brain. The expression patterns of these genes are correlated with brain activation patterns of language-related neural processes frequently impaired in ASD. These findings highlight a model whereby genetic risk impacts gene expression (downregulated), which leads to CCV alterations in ASD.

Are Children With Autism More Likely to Retain Object Names When Learning From Colour Photographs or Black-and-White Cartoons?

For the first time, this study investigated whether children with autism spectrum disorder (ASD) and typically developing (TD) children matched on language comprehension (M age equivalent =  ~ 44 months) are more likely to retain words when learning from colour photographs than black-and-white cartoons. Participants used mutual exclusivity to fast map novel word-picture relationships and retention was assessed following a 5-min delay. Children with ASD achieved significantly greater retention accuracy when learning from photographs rather than cartoons and, surprisingly, responded more accurately than TD children when learning from photographs. Our results demonstrate that children with ASD benefit from greater iconicity when learning words from pictures, providing a data-grounded rationale for using colour photographs when administering picture-based interventions.

Comparing cross-situational word learning, retention, and generalisation in children with autism and typical development

Word learning is complicated by referential ambiguity - there are often multiple potential targets for a newly-heard word. While typically developing (TD) children can accurately infer word meanings from cross-situational statistics, specific difficulties tracking word-object co-occurrences may contribute to language impairments in autism spectrum disorder (ASD). Here, we investigate cross-situational word learning as an integrated system including mapping, retention, and generalisation in both typical development and autism. In Study 1, children with ASD were as accurate at disambiguating the meanings of novel words from statistical correspondences as TD controls matched on receptive vocabulary. In Study 2, both populations spontaneously utilised social and non-social attentional cues to facilitate and accelerate their mapping of word-referent relationships. Across Studies 1 and 2, both groups retrieved and generalised word-referent representations with impressive and comparable accuracy. Although children with ASD performed very similarly to TD children on measures of learning accuracy, they were significantly slower to identify correct referents under both cued and non-cued learning conditions. These findings indicate that mechanisms supporting cross-situational word learning, and the relationships between them, are not qualitatively atypical in language-delayed children with ASD. However, the increased time required to generate correct responses suggests that these mechanisms may be less efficient, potentially impacting learning in natural environments where visual and auditory stimuli are presented rapidly. Our data support claims that word learning in the longer term is driven by the gradual accumulation of word-object associations over multiple learning instances and could potentially inform the development of interventions designed to scaffold word learning.

An investigation into maternal use of telegraphic input to children with Down syndrome

Maternal input influences language development in children with Down syndrome (DS) and typical development (TD). Telegraphic input, or simplified input violating English grammatical rules, is controversial in speech-language pathology, yet no research to date has investigated whether mothers of children with DS use telegraphic input. This study investigated the quality of linguistic input to children with DS compared to age-matched children with TD, and the relationship between maternal input and child language abilities. Mothers of children with DS simplified their input in multiple ways, by using a lower lexical diversity, shorter utterances, and more telegraphic input compared to mothers of children with TD. Telegraphic input was not significantly correlated with other aspects of maternal input or child language abilities. Since children with DS demonstrate specific deficits in grammatical compared to lexical abilities, future work should investigate the long-term influence of maternal telegraphic input on language development in children with DS.

An eye-tracking study of selective trust development in children with and without autism spectrum disorder

The purpose of this study was to explore whether children with autism display selectivity in social learning. We investigated the processing of word mappings provided by speakers who differed on previously demonstrated accuracy and on potential degree of reliability in three groups of children (children with autism spectrum disorder, children with developmental language disorder, and typically developing children) aged 4-9 years. In Task 1, one speaker consistently misnamed familiar objects and the second speaker consistently gave correct names. In Task 2, both speakers provided correct information but differed on how they could achieve this accuracy. We analyzed how the speakers' profiles influenced children's decisions to rely on them in order to learn novel words. We also examined how children attended to the speakers' testimony by tracking their eye movements and comparing children' gaze distribution across speakers' faces and objects of their choice. Results show that children rely on associative trait attribution heuristics to selectively learn from accurate speakers. In Task 1, children in all groups preferred the novel object selected by accurate speakers and directly avoided information provided by previously inaccurate speakers, as revealed by the eye-tracking data. In Task 2, where more sophisticated reasoning about speakers' reliability was required, only children in the typically developing group performed above chance. Nonverbal intelligence score emerged as a predictor of children's preference for more reliable informational sources. In addition, children with autism exhibited reduced attention to speakers' faces compared with children in the comparison groups.

Referent selection in children with Autism Spectrum Condition and intellectual disabilities: Do social cues affect word-to-object or word-to-location mappings?

BACKGROUND

There is conflicting evidence regarding whether children with Autism Spectrum Condition (ASC) and intellectual disabilities (ID) follow social pragmatic cues such as a speaker's eye gaze or pointing towards a novel object to assist mapping a new word onto a new object (e.g. fast mapping).

AIMS

We test fast mapping from a speaker's gaze and pointing towards objects in children with ASC and ID with varying chronological and receptive language ages compared with receptive language matched groups of typically developing (TD) children.

METHODS AND PROCEDURE

Across eight trials, a speaker gazed and/or pointed towards one out of two objects while saying a new word. Pointing was either 'referential' (with intention), or 'incidental' (without obvious intention). To investigate whether children formed more robust word-to-object links rather than associative word-to-location ones, we reversed the original location of the objects in half of the test trials.

OUTCOMES AND RESULTS

Children with ASC were as successful as TD children using social cues to form word-to-object mappings. Surprisingly, children with ID did not fast map from referential pointing, or when objects changed location.

CONCLUSIONS AND IMPLICATIONS

Children with ID may use different processes to facilitate word learning compared to TD children and even children with ASC.

Cross-situational and ostensive word learning in children with and without autism spectrum disorder

Numerous experimental studies have shown that infants and children can discover word meanings by using co-occurrences between labels and objects across individually ambiguous contexts-a phenomenon known as cross-situational learning. Like typically developing children, high-functioning school aged children with autism spectrum disorder (ASD) are capable of cross-situational learning. However, it is not yet clear whether cross-situational learning is similarly available to children with ASD who are younger and show a broader range of language and cognitive abilities. Using eye-tracking methodology, the current study provided the first evidence that preschool and early school-aged children with ASD can rely on cross-situational statistics to learn new words. In fact, children with ASD learned as well as typically developing children with similar vocabulary knowledge. In both groups, the children with the highest cross-situational learning accuracy were those who showed the best familiar word processing skills. Surprisingly, children in both groups learned words equally well in the cross-situational task and an ostensive word-learning task, which presented only a single label-object pairing at a time. In combination, these results point to similarities in the word learning abilities available to typically developing children and children with ASD.

Distributional Cues to Language Learning in Children With Intellectual Disabilities

Purpose

In typical development, distributional cues-patterns in input-are related to language acquisition processes. Statistical and implicit learning refer to the utilization of such cues. In children with intellectual disability, much less is known about the extent to which distributional cues are harnessed in mechanisms of language learning.

Method

This tutorial presents what is known about the process of language learning in children with language impairments associated with different sources of intellectual disability: Williams syndrome, autism spectrum disorder, Down syndrome, and fragile X syndrome.

Results

A broad view is taken on distributional cues relevant to language learning, including statistical learning (e.g., transitional probabilities) and other patterns that support lexical acquisition (e.g., sensitivities to sound patterns, cross-situational word learning) or relate to syntactic development (e.g., nonadjacent dependencies).

Conclusions

Critical gaps in the literature are highlighted. Research in this area is especially limited for Down syndrome and fragile X syndrome. Future directions for taking learning theories into account in interventions for children with intellectual disability are discussed, with a focus on the importance of language input.

Statistical word learning in children with autism spectrum disorder and specific language impairment

BACKGROUND

Word learning is an important component of language development that influences child outcomes across multiple domains. Despite the importance of word knowledge, word-learning mechanisms are poorly understood in children with specific language impairment (SLI) and children with autism spectrum disorder (ASD). This study examined underlying mechanisms of word learning, specifically, statistical learning and fast-mapping, in school-aged children with typical and atypical development.

METHODS

Statistical learning was assessed through a word segmentation task and fast-mapping was examined in an object-label association task. We also examined children's ability to map meaning onto newly segmented words in a third task that combined exposure to an artificial language and a fast-mapping task.

RESULTS

Children with SLI had poorer performance on the word segmentation and fast-mapping tasks relative to the typically developing and ASD groups, who did not differ from one another. However, when children with SLI were exposed to an artificial language with phonemes used in the subsequent fast-mapping task, they successfully learned more words than in the isolated fast-mapping task. There was some evidence that word segmentation abilities are associated with word learning in school-aged children with typical development and ASD, but not SLI. Follow-up analyses also examined performance in children with ASD who did and did not have a language impairment. Children with ASD with language impairment evidenced intact statistical learning abilities, but subtle weaknesses in fast-mapping abilities.

CONCLUSIONS

As the Procedural Deficit Hypothesis (PDH) predicts, children with SLI have impairments in statistical learning. However, children with SLI also have impairments in fast-mapping. Nonetheless, they are able to take advantage of additional phonological exposure to boost subsequent word-learning performance. In contrast to the PDH, children with ASD appear to have intact statistical learning, regardless of language status; however, fast-mapping abilities differ according to broader language skills.

Can Children with Autism Spectrum Disorders Learn New Vocabulary From Linguistic Context?

This study investigated whether children with autism spectrum disorders (ASD) can learn vocabulary from linguistic context. Thirty-five children with ASD (18 with age-appropriate structural language; 17 with language impairment [ALI]) and 29 typically developing peers were taught 20 Science words. Half were presented in linguistic context from which meaning could be inferred, whilst half were accompanied by an explicit definition. Children with ASD were able to learn from context. Condition did not influence phonological learning, but receptive semantic knowledge was greatest in the context condition, and expressive semantic knowledge greatest in the definitional condition. The ALI group learnt less than their peers. This suggests that at least some vocabulary should be taught explicitly, and children with ALI may need additional tuition.

[Pragmatics in autism spectrum disorder: recent developments]

Autism spectrum disorder (ASD) is characterized by primary pragmatic difficulties, out of step with verbal and non-verbal developmental level. This selective survey paper addresses three recent domains of research on pragmatic functions in autism. First, we provide an up-to-date discussion of how lack of sensitivity to social cues impacts early acquisition of words. Second, we review recent findings on the comprehension of non-literal language, pointing to a more refined clinical reality. Third, we describe recent developments in the study of conversation skills in autism.

The integrity of lexical acquisition mechanisms in autism spectrum disorders: A research review

Research on autism spectrum disorders (ASD) has rapidly expanded in recent years, yielding important developments in both theory and practice. While we have gained important insights into how children with ASD differ from typically developing (TD) children in terms of phenotypic features, less has been learned about if and how development in ASD differs from typical development in terms of underlying mechanisms of change. This article aims to provide a review of processes subserving lexical development in ASD, with the goal of identifying contributing factors to the heterogeneity of language outcomes in ASD. The focus is on available evidence of the integrity or disruption of these mechanisms in ASD, as well as their significance for vocabulary development; topics include early speech perception and preference, speech segmentation, word learning, and category formation. Significant gaps in the literature are identified and future directions are suggested. Autism Res 2016, 9: 810-828. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

Children with ASD can use gaze to map new words

BACKGROUND

The conclusion that children with autism spectrum disorders (ASD) do not use eye gaze in the service of word learning is based on one-trial studies.

AIMS

To determine whether children with ASD come to use gaze in the service of word learning when given multiple trials with highly reliable eye-gaze cues.

METHODS & PROCEDURES

Fifteen children with ASD with a mean age of 59 months (range = 36-92 months) and 15 typically developing (TD) peers with a mean age of 37 months (range = 16-92 months), and matched to the ASD group on receptive vocabulary raw scores, participated in four conditions formed by crossing-gaze load (high versus low) and attention load (high versus low). The high eye-gaze load condition required the children to shift attention to the examiner and follow her gaze to fast map new words correctly. The low-gaze load did not require shift and follow behaviours. The high-attention condition involved three (as opposed to one) distracter objects.

OUTCOMES & RESULTS

As compared with the TD group, a lower proportion of the ASD group shifted and followed the examiner on the initial trial of the high-gaze load condition, but there was not a significant difference between groups when shift and follow behaviours were averaged over subsequent trials, nor was there a difference between groups in fast-mapping performance. Fast-mapping outcomes were correlated with gaze shift and follow behaviours in the high-gaze load condition.

CONCLUSIONS & IMPLICATIONS

The finding that the children with ASD altered their looking behaviour over the course of the experiment suggests that children with ASD were sensitive to statistical regularities present in the examiner's gaze cues and used this information to alter their looking behaviour over the course of the experiment.

Lexical Processing in School-Age Children with Autism Spectrum Disorder and Children with Specific Language Impairment: The Role of Semantics

Children with autism spectrum disorder (ASD) and specific language impairment (SLI) often have immature lexical-semantic knowledge; however, the organization of lexical-semantic knowledge is poorly understood. This study examined lexical processing in school-age children with ASD, SLI, and typical development, who were matched on receptive vocabulary. Children completed a lexical decision task, involving words with high and low semantic network sizes and nonwords. Children also completed nonverbal updating and shifting tasks. Children responded more accurately to words from high than from low semantic networks; however, follow-up analyses identified weaker semantic network effects in the SLI group. Additionally, updating and shifting abilities predicted lexical processing, demonstrating similarity in the mechanisms which underlie semantic processing in children with ASD, SLI, and typical development.

Effect of speaker gaze on word learning in fragile X syndrome: a comparison with nonsyndromic autism spectrum disorder

PURPOSE

This study examined use of a speaker's direction of gaze during word learning by boys with fragile X syndrome (FXS), boys with nonsyndromic autism spectrum disorder (ASD), and typically developing (TD) boys.

METHOD

A fast-mapping task with follow-in and discrepant labeling conditions was administered. We expected that the use of speaker gaze would lead to participants selecting as the referent of the novel label the object to which they attended in follow-in trials and the object to which the examiner attended in the discrepant labeling trials. Participants were school-aged boys with FXS (n=18) or ASD (n=18) matched on age, intelligence quotient, and nonverbal cognition and younger TD boys (n=18) matched on nonverbal cognition.

RESULTS

All groups performed above chance in both conditions, although the TD boys performed closest to the expected pattern. Boys with FXS performed better during follow-in than in discrepant label trials, whereas TD boys and boys with ASD did equally well in both trial types. The type of trial administered first influenced subsequent responding. Error patterns also distinguished the groups.

CONCLUSION

The ability to utilize a speaker's gaze during word learning is not as well developed in boys with FXS or nonsyndromic ASD as in TD boys of the same developmental level.