Commentary: Time to reconceptualize ASD? comments on Happe and Frith (2020) and Sonuga-Barke (2020).

Happe and Frith (2020) list seven changes in the concept of autism that have taken place since the 80s when autism became the focus of clinical concerns and research interests. These dramatic changes, supported by additional research results, have not convinced Sonuga-Barke (2020) that a Kuhnian revolution in psychiatric nosology may be at our front door. This commentary will discuss this conclusion, calling on ASD researchers to re-evaluate the benefits of a paradigm shift in the nosology of ASD.

'Developmental Delay' Reconsidered: The Critical Role of Age-Dependent, Co-variant Development.

In memory of Annette Karmiloff-Smith . This paper reviews recent neurobiological research reporting structural co-variance and temporal dependencies in age-dependent gene expression, parameters of cortical maturation, long range connectivity and interaction of the biological network with the environment. This research suggests that age by size trajectories of brain structures relate to functional properties more than absolute sizes. In line with these findings, recent behavioral studies of typically developing children whose language development was delayed reported long term consequences of such delays. As for neurodevelopmental disorders, disrupted developmental timing and slow acquisitional pace are hallmarks of these populations. It is argued that these behavioral and neuro-biological results highlight the need to commit to a developmental model which will reflect the fact that temporal dependencies overseeing structural co-variance among developmental components are major regulatory factors of typical development of the brain/mind network. Consequently, the concept of 'developmental delay' in developmental theorizing needs to be reconsidered.

Pathways to language: a naturalistic study of children with Williams syndrome and children with Down syndrome.

This is a naturalistic study of the development of language in Hebrew-speaking children with Williams syndrome (WS) and children with Down syndrome (DS), whose MLU extended from 1·0 to 4·4. Developmental curves over the entire span of data collection revealed minor differences between children with WS, children with DS, and typically developing (TD) controls of similar MLU. Development within one calendar year showed remarkable synchrony among the variables. However, age of language onset and pace of acquisition departed significantly from normal timing. It is argued that in view of the centrality of genetic timing and the network properties of cognition, normal schedules are crucial determinants of intact development. Consequently, with respect to neurodevelopmental syndromes, the so-called 'language delay' is indicative of deviance that is likely to impact development in critical ways.

No reason to expect "reading universals".

Writing systems encode linguistic information in diverse ways, relying on cognitive procedures that are likely to be general purpose rather than specific to reading. Optimality in reading for meaning is achieved via the entire communicative act, involving, when the need arises, syntax, nonlinguistic context, and selective attention.

IQ predicts word decoding skills in populations with intellectual disabilities.

This is a study of word decoding in adolescents with Down syndrome and in adolescents with Intellectual Deficits of unknown etiology. It was designed as a replication of studies of word decoding in English speaking and in Hebrew speaking adolescents with Williams syndrome (Levy & Antebi, 2004; Levy, Smith, & Tager-Flusberg, 2003). Participants' IQ was matched to IQ in the groups with Williams syndrome and was within the range of mental retardation or borderline intelligence. Our aim was to investigate the impact of IQ on word decoding in these populations, rather than estimate their overall reading level. Similar to the results seen in people with Williams syndrome, word decoding was correlated with auditory short term memory and with phonological awareness tasks yet these correlations were mediated by IQ. It is argued that learning to decode is an explicit task that relies primarily on general cognitive resources of the kind that are most vulnerable in people with sub-normal IQ.

Abnormal white matter integrity in young children with autism.

This study investigated white matter integrity in young children with autism using diffusion tensor imaging (DTI). Twenty-two children with autism, mean age 3:2 years, and 32 controls, mean age 3:4 years, participated in the study. Tract-based spatial statistics (TBSS) revealed white matter abnormalities in several distinct clusters within the genu and body of the corpus callosum (CC), left superior longitudinal fasciculus (SLF) and right and left cingulum (Cg). TBSS-VOIs analysis was performed in the clusters where differences in fractional anisotropy (FA) were detected to investigate the relationship between changes in FA and diffusivity indices. In all VOIs, increase in FA was caused by a decrease in radial diffusivity (Dr), while no changes in axial diffusivity (Da) or mean diffusivity (MD) were observed. Tractography analysis was applied to further study the CC, SLF, and Cg. Witelson parcellation scheme was used for the CC. Significant increase in FA was seen in children with autism in the mid-body of the CC as well as in the left Cg. It is suggested that such abnormal white matter integrity in young children with autism may adversely affect connectivity between different brain regions and may be linked to some of the behavioral impairments apparent in autism.

Language performance in siblings of nonverbal children with autism.

The study focuses on language and cognitive abilities of siblings of the linguistically most affected children with autism (i.e. siblings of nonverbal children - SIBS-ANV). Twenty-eight SIBS-ANV (17 boys), ages 4-9 years, took part in the study. All children attended regular schools, and none had received a diagnosis of autism. Controls were 27 typically developing children (SIBS-TD; 16 boys) matched to the SIBS-ANV on age, family background, socioeconomic status and type of school they attended. Significant IQ differences, as well as language differences as measured on the Clinical Evaluation of Language Fundamentals (CELF), emerged between SIBS-ANV and SIBS-TD. However, differences in the language scores mostly disappeared when PIQ and FSIQ were controlled for. Furthermore, grammatical analysis of spontaneous speech samples produced in the course of testing did not reveal any significant differences between the groups. These results add to recent work suggesting that language deficits may not be part of the Broad Autism Phenotype (BAP). It further suggests that the cognitive deficit characteristic of nonverbal people with autism may be familial.

Covert processing of facial expressions by people with Williams syndrome.

Although individuals with Williams Syndrome (WS) are empathic and sociable and perform relatively well on face recognition tasks, they perform poorly on tasks of facial expression recognition. The current study sought to investigate this seeming inconsistency. Participants were tested on a Garner-type matching paradigm in which identities and expressions were manipulated simultaneously as the relevant or irrelevant dimensions. Performance of people with WS on the expression-matching task was poor and relied primarily on facilitation afforded by congruent identities. Performance on the identity matching task came close to the level of performance of matched controls and was significantly facilitated by congruent expressions. We discuss potential accounts for the discrepant processing of expressions in the task-relevant (overt) and task-irrelevant (covert) conditions, expanding on the inherently semantic-conceptual nature of overt expression matching and its dependence on general cognitive level.

Special issue on developmental delay.

A significant percentage of children, ages 0-5 years, present with developmental delays. Delays can be global (GDD), when two or more developmental areas manifest at least 6 months delays, or specific (SDD)when it relates to a single functional area. This special issue reviews etiologies as well as clinical and research uses of the term, focusing on the potential for arriving at earlier specific diagnoses in cases of CP, ADHD, ASD and language impairments (LI).

Developmental delay revisited.

This article presents current neurobiological concepts that highlight the critical role of chronological age in determining optimal development. The role of sensitive periods, experience expectancy, gene expression, and gene-age interactions is discussed. The debate between "splitters" and "lumpers" is presented in light of the review articles in this special issue. The conclusion from this study is that in a significant proportion of cases, earlier diagnoses are possible, avoiding the all-encompassing developmental delay/global developmental delay, and opening up possibilities of early interventions. It is further argued that research methodology might benefit from early diagnoses as well.

Research review: crossing syndrome boundaries in the search for brain endophenotypes.

The inherent imprecision of behavioral phenotyping is the single most important factor contributing to the failure to discover the biological factors that are involved in psychiatric and neurodevelopmental disorders (e.g., Bearden & Freimer, 2006). In this review article we argue that in addition to an appreciation of the inherent complexity at the biological level, a rather urgent task facing behavioral scientists involves a reconsideration of the role that clinical syndromes play in psychological theorizing, as well as in research into the biological basis of cognition and personality. Syndrome heterogeneity, cross-syndrome similarities and syndrome comorbidities question the relevance of syndromes to biological research. It is suggested that the search for brain endophenotypes, intermediate between genes and behavior, should be based on cross-syndrome, trait classification. Cohort selection should rest on behavioral homogeneity, enabling, when necessary, syndrome heterogeneity.

Interactive processes in matching identity and expressions of unfamiliar faces: evidence for mutual facilitation effects.

We investigated the interactions between matching identity and expressions of unfamiliar faces. In experiment 1, participants matched expressions in frontal and in oblique views, while we manipulated facial identity. In experiment 2, participants matched identity in frontal and in oblique views, while facial expressions were manipulated. Labeling of expressions was not required. Results showed mutual facilitation between matching facial identity and facial expressions, in accuracy as well as in reaction times. Thus, matching expressions was better and faster for same-identity images in oblique as well as in frontal views (experiment 1), and matching identity was better and faster for same-expression images in oblique as well as in frontal views (experiment 2). The discussion focuses on the implications of these results for the structural encoding of facial identity and facial expressions.

Accelerated maturation of white matter in young children with autism: a high b value DWI study.

The goal of this work was to study white matter maturation in young children with autism following previous reports of increased cerebral volume during early development, as well as arguments for abnormal neural growth patterns and regulation at this critical developmental period. We applied diffusion tensor imaging (DTI) and high b value diffusion-weighted imaging (DWI) to young children diagnosed with autism and to a typically developing (TD) control group. Fractional anisotropy (FA), probability and displacement were measured in overall analysis as well as in regions of interest (ROI). Individual data points of children with autism were compared to the developmental curves obtained from typically developing children. Increased restriction, reflected in significantly increased FA and probability along with reduced displacement values, was detected in overall analysis as well as in several brain regions. Increased restriction, suggesting an early and accelerated abnormal maturation of white matter, was more dominant in the left hemisphere and was mainly detected in the frontal lobe. No changes were detected in the occipital lobes. These results support previous claims of abnormal brain overgrowth in young children with autism and are in contrast to the decreased restricted diffusion reported in previous studies in adolescent with autism.

Language in boys with fragile X syndrome.

The current paper reports of language production in 15 Hebrew-speaking boys, aged 9;0-13;0, with fully methylated, non-mosaic fragile X syndrome and no concomitant diagnosis of autism. Contrary to expectations, seven children were non-verbal. Language production in the verbal children was studied in free conversations and in context-bound speech. Despite extra caution in calculating MLU, participants' language level was not predicted by mean utterance length. Context bound speech resulted in grammatically more advanced performance than free conversation, and performance in both contexts differed in important ways from performance of typically developing MLU-matched controls. The relevance of MLU as a predictor of productive grammar in disordered populations is briefly discussed.

The processing of morphology in old age: evidence from Hebrew.

PURPOSE: Taking advantage of the rich morphological structure of Hebrew, the current article aims to examine whether age affects the processing of morphological forms through an investigation of 2 systematic morphological paradigms. METHOD: Forty-eight young and 48 old Hebrew speakers completed 2 experiments: the 1st investigated sensitivity to subject-verb gender incongruity in a reading task, and the 2nd examined parsing of pseudoverbs containing existing and nonexisting consonantal roots in a lexical-decision task. RESULTS: Older adults were slower relative to the young, but both groups were slower on incongruent relative to congruent targets and on a pseudoverb with a real root relative to a pseudoverb with a nonexistent root. In both experiments the interaction between condition and age was statistically significant. CONCLUSIONS: While older adults demonstrate preserved morphological parsing abilities, possible explanations for the interaction effect include cognitive slowing or deficient inhibitory control.

A longitudinal study of language development in two children with Williams syndrome.

Williams syndrome (WS) is often cited as the prime example within developmental disorders of the dissociation of language from other cognitive skills, particularly from visuo-motor skills. This claim has been responsible for the challenges posed by this population to cognitive theories and to models of language acquisition. Two Hebrew-speaking children with WS were followed longitudinally for 18 months, from the first occurrences of two word combinations. Y was 3.9-5.3 and BT was 4.2-5.8 during data collection. Both children had an MLU of 1.8-2.8. The children's linguistic profiles were compared to the profiles of typically-developing (TD) children of similar MLU as well as to the profiles of 11 children with a variety of neurodevelopmental disorders (ND), matched on MLU. The profiles exhibited by the children with WS throughout the period of the study differed from the profiles seen in both control groups.

Preserved morphological decomposition in persons with Alzheimer's disease.

Persons with Alzheimer's disease (AD) demonstrate a severe lexical impairment that affects conceptual knowledge. Research into aspects of word structure and the structural relationships between words, however, has been scarce in this population. Taking advantage of the rich morphology of Hebrew, the current article examines the status of morphological decomposition in AD. Fourteen persons with AD and 48 control participants completed 2 experiments: The 1st investigated root extraction from pseudoverbs containing existing and nonexisting consonantal roots, and the 2nd looked at sensitivity to morphological priming effects. Results suggest that despite severe semantic-conceptual deficits on naming, fluency, and comprehension tasks, persons with AD engage in adequate morphological decomposition of words, in a similar manner to normal adult speakers of Hebrew.

Word reading and reading-related skills in Hebrew-speaking adolescents with Williams syndrome.

This study investigated word reading and reading-related skills in 17 Hebrew-speaking individuals with Williams syndrome, ages 11-22. Reading of real words was at the third grade level, yet six participants could not read nonce words at all. The relatively high percentage of nonreaders could be a consequence of the special characteristics of Hebrew orthography, which realizes consonants as letters and vowels as diacritic dots and dashes below and above the line. In the group as a whole, reading real and nonce words did not correlate with rapid naming. Yet, contrary to research on dyslexia, word reading correlated with IQ as well as with performance on phonological awareness tasks.