Screening for autism spectrum disorders in 12-month-old high-risk siblings by parental report

This study examines whether parental report of social-communicative and repetitive behaviors at 12 months can be helpful in identifying autism spectrum disorder (ASD) in younger siblings of children with ASD [high-risk (HR)-siblings]. Parents of HR-siblings and infants without a family history of ASD completed the First Year Inventory at 12 months. Developmental outcomes were based on 24- or 36-month assessments. HR-siblings later diagnosed with ASD showed greater impairments in social communication than those with other developmental outcomes based on parental and clinician ratings. Parental report of decline in play and communication and impaired vocal imitation correctly classified a majority of ASD cases with high specificity. These preliminary findings have important implications for the development of early screening instruments for ASD in HR-siblings.

Early-emerging social adaptive skills in toddlers with autism spectrum disorders: an item analysis

Individuals with ASD have significant impairments in adaptive skills, particularly adaptive socialization skills. The present study examined the extent to which 20 items from the Vineland Adaptive Behavior Scales-Socialization Domain differentiated between ASD and developmentally delayed (DD) groups. Participants included 108 toddlers with ASD or DD under the age of 3 years. Nine of the 20 items significantly distinguished the groups. The ASD group demonstrated significantly weaker socialization skills, including deficits in basic social behaviors. The results support the notion that (a) socialization deficits in ASD impact foundational social skills typically emerging in the first year of life, (b) examination of specific social adaptive behaviors contribute to differential diagnosis, and (c) foundational social behaviors should be targeted for intervention.

18-month predictors of later outcomes in younger siblings of children with autism spectrum disorder: a baby siblings research consortium study

OBJECTIVE

Younger siblings of children with autism spectrum disorder (ASD) are at high risk (HR) for developing ASD as well as features of the broader autism phenotype. Although this complicates early diagnostic considerations in this cohort, it also provides an opportunity to examine patterns of behavior associated specifically with ASD compared to other developmental outcomes.

METHOD

We applied Classification and Regression Trees (CART) analysis to individual items of the Autism Diagnostic Observation Schedule (ADOS) in 719 HR siblings to identify behavioral features at 18 months that were predictive of diagnostic outcomes (ASD, atypical development, and typical development) at 36 months.

RESULTS

Three distinct combinations of features at 18 months were predictive of ASD outcome: poor eye contact combined with lack of communicative gestures and giving; poor eye contact combined with a lack of imaginative play; and lack of giving and presence of repetitive behaviors, but with intact eye contact. These 18-month behavioral profiles predicted ASD versus non-ASD status at 36 months with 82.7% accuracy in an initial test sample and 77.3% accuracy in a validation sample. Clinical features at age 3 years among children with ASD varied as a function of their 18-month symptom profiles. Children with ASD who were misclassified at 18 months were higher functioning, and their autism symptoms increased between 18 and 36 months.

CONCLUSION

These findings suggest the presence of different developmental pathways to ASD in HR siblings. Understanding such pathways will provide clearer targets for neural and genetic research and identification of developmentally specific treatments for ASD.

Interest level in 2-year-olds with autism spectrum disorder predicts rate of verbal, nonverbal, and adaptive skill acquisition

Recent studies have suggested that skill acquisition rates for children with autism spectrum disorders receiving early interventions can be predicted by child motivation. We examined whether level of interest during an Autism Diagnostic Observation Schedule assessment at 2 years predicts subsequent rates of verbal, nonverbal, and adaptive skill acquisition to the age of 3 years. A total of 70 toddlers with autism spectrum disorder, mean age of 21.9 months, were scored using Interest Level Scoring for Autism, quantifying toddlers' interest in toys, social routines, and activities that could serve as reinforcers in an intervention. Adaptive level and mental age were measured concurrently (Time 1) and again after a mean of 16.3 months of treatment (Time 2). Interest Level Scoring for Autism score, Autism Diagnostic Observation Schedule score, adaptive age equivalent, verbal and nonverbal mental age, and intensity of intervention were entered into regression models to predict rates of skill acquisition. Interest level at Time 1 predicted subsequent acquisition rate of adaptive skills (R(2) = 0.36) and verbal mental age (R(2) = 0.30), above and beyond the effects of Time 1 verbal and nonverbal mental ages and Autism Diagnostic Observation Schedule scores. Interest level at Time 1 also contributed (R(2) = 0.30), with treatment intensity, to variance in development of nonverbal mental age.

Early generalized overgrowth in autism spectrum disorder: prevalence rates, gender effects, and clinical outcomes

OBJECTIVE

Although early head and body overgrowth have been well documented in autism spectrum disorder (ASD), their prevalence and significance remain unclear. It is also unclear whether overgrowth affects males and females differentially, and whether it is associated with clinical outcomes later in life.

METHOD

To evaluate prevalence of somatic overgrowth, gender effects, and associations with clinical outcomes, head circumference, height, and weight measurements were collected retrospectively between birth and 2 years of age in toddlers with ASD (n = 200) and typically developing (TD; n = 147) community controls. Symptom severity, verbal, and nonverbal functioning were assessed at 4 years.

RESULTS

Abnormalities in somatic growth in infants with ASD were consistent with early generalized overgrowth (EGO). Boys but not girls with ASD were larger and exhibited an increased rate of extreme EGO compared to community controls (18.0% versus 3.4%). Presence of a larger body at birth and postnatal overgrowth were associated independently with poorer social, verbal, and nonverbal skills at 4 years.

CONCLUSION

Although early growth abnormalities in ASD are less common than previously thought, their presence is predictive of lower social, verbal, and nonverbal skills at 4 years, suggesting that they may constitute a biomarker for identifying toddlers with ASD at risk for less-optimal outcomes. The results highlight that the search for mechanisms underlying atypical brain development in ASD should consider factors responsible for both neural and nonneural tissue development during prenatal and early postnatal periods, and can be informed by the finding that early overgrowth may be more readily observed in males than in females with ASD.

On Relationships Between Fixation Identification Algorithms and Fractal Box Counting Methods

Fixation identification algorithms facilitate data comprehension and provide analytical convenience in eye-tracking analysis. However, current fixation algorithms for eye-tracking analysis are heavily dependent on parameter choices, leading to instabilities in results and incompleteness in reporting. This work examines the nature of human scanning patterns during complex scene viewing. We show that standard implementations of the commonly used distance-dispersion algorithm for fixation identification are functionally equivalent to greedy spatiotemporal tiling. We show that modeling the number of fixations as a function of tiling size leads to a measure of fractal dimensionality through box counting. We apply this technique to examine scale-free gaze behaviors in toddlers and adults looking at images of faces and blocks, as well as large number of adults looking at movies or static images. The distributional aspects of the number of fixations may suggest a fractal structure to gaze patterns in free scanning and imply that the incompleteness of standard algorithms may be due to the scale-free behaviors of the underlying scanning distributions. We discuss the nature of this hypothesis, its limitations, and offer directions for future work.

Speech disturbs face scanning in 6-month-old infants who develop autism spectrum disorder

BACKGROUND

From birth, infants show a preference for the faces, gaze, and voices of others. In individuals with autism spectrum disorders (ASDs) these biases seem to be disturbed. The source of these disturbances is not well-understood, but recent efforts have shown that the spontaneous deployment of attention to social targets might be atypical as early as 6 months of age. The nature of this atypical behavior and the conditions under which it arises are currently unknown.

METHODS

We used eye-tracking to examine the gaze patterns of 6-month-old infants (n = 99) at high risk (n = 57) and low risk (n = 42) for developing ASD as they viewed faces that were: 1) still; 2) moving and expressing positive affect; or 3) speaking. Clinical outcomes were determined through a comprehensive assessment at the age of 3 years. The scanning patterns of infants later diagnosed with ASD were compared with infants without an ASD outcome.

RESULTS

Infants who later developed ASD spent less time looking at the presented scenes in general than other infants. When these infants looked at faces, their looking toward the inner features of faces decreased compared with the other groups only when the presented face was speaking.

CONCLUSIONS

Our study suggests that infants later diagnosed with ASD have difficulties regulating attention to complex social scenes. It also suggests that the presence of speech might uniquely disturb the attention of infants who later develop ASD at a critical developmental point when other infants are acquiring language and learning about their social world.

Gaze response to dyadic bids at 2 years related to outcomes at 3 years in autism spectrum disorders: a subtyping analysis

Variability in attention towards direct gaze and child-directed speech may contribute to heterogeneity of clinical presentation in toddlers with autism spectrum disorders (ASD). To evaluate this hypothesis, we clustered sixty-five 20-month-old toddlers with ASD based on their visual responses to dyadic cues for engagement, identifying three subgroups. Subsequently, we compared social, language, and adaptive functioning of these subgroups at 3 years of age. The cluster displaying limited attention to social scenes in general exhibited poor outcome at 3 years; the cluster displaying good attention to the scene and to the speaker's mouth was verbal and high functioning at 3 years. Analysis of visual responses to dyadic cues may provide a clinically meaningful approach to identifying early predictors of outcome.

Decreased spontaneous attention to social scenes in 6-month-old infants later diagnosed with autism spectrum disorders

BACKGROUND

The ability to spontaneously attend to the social overtures and activities of others is essential for the development of social cognition and communication. This ability is critically impaired in toddlers with autism spectrum disorders (ASD); however, it is not clear if prodromal symptoms in this area are already present in the first year of life of those affected by the disorder.

METHODS

To examine whether 6-month-old infants later diagnosed with ASD exhibit atypical spontaneous social monitoring skills, visual responses of 67 infants at high-risk and 50 at low-risk for ASD were studied using an eye-tracking task. Based on their clinical presentation in the third year, infants were divided into those with ASD, those exhibiting atypical development, and those developing typically.

RESULTS

Compared with the control groups, 6-month-old infants later diagnosed with ASD attended less to the social scene, and when they did look at the scene, they spent less time monitoring the actress in general and her face in particular. Limited attention to the actress and her activities was not accompanied by enhanced attention to objects.

CONCLUSIONS

Prodromal symptoms of ASD at 6 months include a diminished ability to attend spontaneously to people and their activities. A limited attentional bias toward people early in development is likely to have a detrimental impact on the specialization of social brain networks and the emergence of social interaction patterns. Further investigation into its underlying mechanisms and role in psychopathology of ASD in the first year is warranted.

Pivotal response treatment for infants at-risk for autism spectrum disorders: a pilot study

Presently there is limited research to suggest efficacious interventions for infants at-risk for autism. Pivotal response treatment (PRT) has empirical support for use with preschool children with autism, but there are no reports in the literature utilizing this approach with infants. In the current study, a developmental adaptation of PRT was piloted via a brief parent training model with three infants at-risk for autism. Utilizing a multiple baseline design, the data suggest that the introduction of PRT resulted in increases in the infants' frequency of functional communication and parents' fidelity of implementation of PRT procedures. Results provide preliminary support for the feasibility and utility of PRT for very young children at-risk for autism.

Predicting developmental status from 12 to 24 months in infants at risk for Autism Spectrum Disorder: a preliminary report

The study examined whether performance profiles on individual items of the Toddler Module of the Autism Diagnostic Observation Schedule at 12 months are associated with developmental status at 24 months in infants at high and low risk for developing Autism Spectrum Disorder (ASD). A nonparametric decision-tree learning algorithm identified sets of 12-month predictors of developmental status at 24 months. Results suggest that identification of infants who are likely to exhibit symptoms of ASD at 24 months is complicated by variable patterns of symptom emergence. Fine-grained analyses linking specific profiles of strengths and deficits with specific patterns of symptom emergence will be necessary for further refinement of screening and diagnostic instruments for ASD in infancy.

Somatic copy number mosaicism in human skin revealed by induced pluripotent stem cells

Reprogramming human somatic cells into induced pluripotent stem cells (iPSCs) has been suspected of causing de novo copy number variations (CNVs)^1-4. To explore this issue, we performed a whole-genome and transcriptome analysis of 20 human iPSC lines derived from primary skin fibroblasts of 7 individuals using next-generation sequencing. We find that, on average, an iPSC line manifests two CNVs not apparent in the fibroblasts from which the iPSC was derived. Using qPCR, PCR, and digital droplet PCR (ddPCR), we show that at least 50% of those CNVs are present as low frequency somatic genomic variants in parental fibroblasts (i.e. the fibroblasts from which each corresponding hiPSC line is derived) and are manifested in iPSC colonies due to the colonies’ clonal origin. Hence, reprogramming does not necessarily lead to de novo CNVs in iPSC, since most of line-manifested CNVs reflect somatic mosaicism in the human skin. Moreover, our findings demonstrate that clonal expansion, and iPSC lines in particular, can be used as a discovery tool to reliably detect low frequency CNVs in the tissue of origin. Overall, we estimate that approximately 30% of the fibroblast cells have somatic CNVs in their genomes, suggesting widespread somatic mosaicism in the human body. Our study paves the way to understanding the fundamental question of the extent to which cells of the human body normally acquire structural alterations in their DNA post-zygotically.

Practitioner's guide to assessment of autism spectrum disorders in infants and toddlers

Recent advances in clinical research have made it possible to diagnosis autism spectrum disorders (ASD) as early as the second year of life. The diagnostic process early in development is often complex, and thus, familiarity with the most recent findings in clinical assessment instruments, early symptoms, and developmental trajectories of young children with autism is essential. This paper provides an empirically based practitioner's guide to issues and concerns related to early diagnosis of ASD in very young children, documentation of the course and patterns of ASD symptomatology in infants and toddlers, and current understanding in the field of diagnostic outcomes of children identified in the first and second year of life.

Context modulates attention to social scenes in toddlers with autism

BACKGROUND

In typical development, the unfolding of social and communicative skills hinges upon the ability to allocate and sustain attention toward people, a skill present moments after birth. Deficits in social attention have been well documented in autism, though the underlying mechanisms are poorly understood.

METHODS

In order to parse the factors that are responsible for limited social attention in toddlers with autism, we manipulated the context in which a person appeared in their visual field with regard to the presence of salient social (child-directed speech and eye contact) and nonsocial (distractor toys) cues for attention. Participants included 13- to 25-month-old toddlers with autism (autism; n = 54), developmental delay (DD; n = 22), and typical development (TD; n = 48). Their visual responses were recorded with an eye-tracker.

RESULTS

In conditions devoid of eye contact and speech, the distribution of attention between key features of the social scene in toddlers with autism was comparable to that in DD and TD controls. However, when explicit dyadic cues were introduced, toddlers with autism showed decreased attention to the entire scene and, when they looked at the scene, they spent less time looking at the speaker's face and monitoring her lip movements than the control groups. In toddlers with autism, decreased time spent exploring the entire scene was associated with increased symptom severity and lower nonverbal functioning; atypical language profiles were associated with decreased monitoring of the speaker's face and her mouth.

CONCLUSIONS

While in certain contexts toddlers with autism attend to people and objects in a typical manner, they show decreased attentional response to dyadic cues for attention. Given that mechanisms supporting responsivity to dyadic cues are present shortly after birth and are highly consequential for development of social cognition and communication, these findings have important implications for the understanding of the underlying mechanisms of limited social monitoring and identifying pivotal targets for treatment.

Early generalized overgrowth in boys with autism

CONTEXT

Multiple studies have reported an overgrowth in head circumference (HC) in the first year of life in autism. However, it is unclear whether this phenomenon is independent of overall body growth and whether it is associated with specific social or cognitive features.

OBJECTIVES

To examine the trajectory of early HC growth in autism compared with control groups; to assess whether HC growth in autism is independent of height and weight growth during infancy; and to examine HC growth from birth to 24 months in relationship to social, verbal, cognitive, and adaptive functioning levels.

DESIGN

Retrospective study.

SETTING

A specialized university-based clinic.

PARTICIPANTS

Boys diagnosed as having autistic disorder (n = 64), pervasive developmental disorder-not otherwise specified (n = 34), global developmental delay (n = 13), and other developmental problems (n = 18) and typically developing boys (n = 55).

MAIN OUTCOME MEASURES

Age-related changes in HC, height, and weight between birth and age 24 months; measures of social, verbal, and cognitive functioning at age 2 years.

RESULTS

Compared with typically developing controls, boys with autism were significantly longer by age 4.8 months, had a larger HC by age 9.5 months, and weighed more by age 11.4 months (P = .05 for all). None of the other clinical groups showed a similar overgrowth pattern. Boys with autism who were in the top 10% of overall physical size in infancy exhibited greater severity of social deficits (P = .009) and lower adaptive functioning (P = .03).

CONCLUSIONS

Boys with autism experienced accelerated HC growth in the first year of life. However, this phenomenon reflected a generalized process affecting other morphologic features, including height and weight. The study highlights the importance of studying factors that influence not only neuronal development but also skeletal growth in autism.

Phonology and vocal behavior in toddlers with autism spectrum disorders

The purpose of this study is to examine the phonological and other vocal productions of children, 18-36 months, with autism spectrum disorder (ASD) and to compare these productions to those of age-matched and language-matched controls. Speech samples were obtained from 30 toddlers with ASD, 11 age-matched toddlers and 23 language-matched toddlers during either parent-child or clinician-child play sessions. Samples were coded for a variety of speech-like and nonspeech vocalization productions. Toddlers with ASD produced speech-like vocalizations similar to those of language-matched peers, but produced significantly more atypical nonspeech vocalizations when compared to both control groups. Toddlers with ASD show speech-like sound production that is linked to their language level, in a manner similar to that seen in typical development. The main area of difference in vocal development in this population is in the production of atypical vocalizations. Findings suggest that toddlers with ASDs do not tune into the language model of their environment. Failure to attend to the ambient language environment negatively impacts the ability to acquire spoken language.

Limited attentional bias for faces in toddlers with autism spectrum disorders

CONTEXT

Toddlers with autism spectrum disorders (ASD) exhibit poor face recognition and atypical scanning patterns in response to faces. It is not clear if face-processing deficits are also expressed on an attentional level. Typical individuals require more effort to shift their attention from faces compared with other objects. This increased disengagement cost is thought to reflect deeper processing of these socially relevant stimuli.

OBJECTIVE

To examine if attention disengagement from faces is atypical in the early stages of ASD.

DESIGN

Attention disengagement was tested in a variation of the cued attention task in which participants were required to move their visual attention from face or nonface central fixation stimuli and make a reactive saccade to a peripheral target. The design involved diagnosis as a between-group factor and central fixation stimuli type as a within-group factor.

SETTING

Participants were taken from a cohort of patients at a university-based specialized clinic or from a pool of subjects participating in a prospective study of social cognition in ASD.

PARTICIPANTS

Toddlers with ASD (mean age, 32 months [n = 42]) were compared with toddlers with nonautistic developmental delays (mean age, 29 months [n = 31]) and with typically developing toddlers (mean age, 29 months [n = 46]).

MAIN OUTCOME MEASURE

Saccadic reaction time.

RESULTS

Developmentally delayed and typically developing toddlers had more difficulties disengaging visual attention from faces than toddlers with ASD. This effect was not present in response to nonfacial stimuli. These results suggest that toddlers with ASD are not captivated by faces to the same extent as toddlers without ASD and that this effect is not driven by a generalized impairment in disengagement of attention.

CONCLUSION

The results suggest that face-processing difficulties in toddlers with ASD involve disruption of an attentional mechanism that typically supports deeper processing of these highly socially relevant stimuli.

Looking but not seeing: atypical visual scanning and recognition of faces in 2 and 4-year-old children with autism spectrum disorder

This study used eye-tracking to examine visual scanning and recognition of faces by 2- and 4-year-old children with autism spectrum disorder (ASD) (N = 44) and typically developing (TD) controls (N = 30). TD toddlers at both age levels scanned and recognized faces similarly. Toddlers with ASD looked increasingly away from faces with age, atypically attended to key features of faces, and were impaired in face recognition. Deficits in recognition were associated with imbalanced attention between key facial features. This study illustrates that face processing in ASD may be affected early and become further compromised with age. We propose that deficits in face processing likely impact the effectiveness of toddlers with ASD as social partners and thus should be targeted for intervention.

A prospective study of toddlers with ASD: short-term diagnostic and cognitive outcomes

BACKGROUND

Despite recent increases in the number of toddlers referred for a differential diagnosis of autism spectrum disorders (ASD), knowledge of short-term stability of the early diagnosis as well as cognitive outcomes in this cohort is still limited.

METHOD

Cognitive, social, and communication skills of 89 clinic-referred toddlers were assessed at the average age of 21.5 (SD = 4.9) months, and reassessed at 46.9 (SD = 7.7) months. Groups with stable and unstable diagnostic presentation were identified and compared on their profile of cognitive and social-communicative skills obtained at the time of initial diagnosis.

RESULTS

Stability of the ASD diagnosis was 100%; diagnosis of autism was stable in 74% of cases as compared to 83% and 81% in PDD-NOS and Non-ASD groups, respectively. Worsening of social disability symptoms resulting in autism diagnosis was noted in 17% of toddlers initially diagnosed with PDD-NOS and in 19% of toddlers with initial diagnosis of non-ASD disorder. However, marked improvement was noted in approximately 1/4 of children initially presenting with autism, warranting diagnostic reassignment to PDD-NOS at follow-up. An analysis of developmental skills profiles suggests particular relevance of the assessment of verbal and nonverbal communication skills to diagnostic differentiation between subtypes within ASD in the second year of life.

CONCLUSIONS

Stability of ASD diagnosis in toddlers is high, though marked changes in severity of symptoms is to be expected in a minority of cases. Simultaneous consideration of cognitive, social, and communication skills profiles enhances accuracy of diagnostic classification and prediction of outcome.

Language outcomes of toddlers with autism spectrum disorders: a two year follow-up

Thirty-seven children 15-25 months of age received clinical diagnoses of autism spectrum disorder (ASD) and were re-evaluated two years later. All subjects were judged to have retained a diagnosis of ASD at the follow-up evaluation. Communication scores for the group as a whole during the first visit were significantly lower than nonverbal IQ. However, by the second visit, verbal and nonverbal scores were no longer significantly different. The group was divided into two subgroups, based on expressive language (EL) outcome at the second visit. The two groups were similar in the second year of life in terms of expressive communication skills and autistic symptoms, except for a trend toward more stereotypic and repetitive behavior in the worse outcome group. By the second visit, however, the groups differed significantly on all standard measures of expression and reception, as well as on autistic symptomotology and nonverbal IQ. When assessed during their second year, children who ended up in the better outcome group showed higher average nonverbal cognitive level, receptive language (RL) scores, number of sounds and words produced, use of symbolic play schemes, and response to joint attention bids. Regression analysis revealed that the variables for which significant differences between the two outcome groups in their second year of life were found provided significant prediction of EL outcome at age four. Stepwise regression identified RL and presence of stereotypic and repetitive at the first visit as significantly associated with EL outcome. Implications of these findings for early identification and intervention are discussed.

The modified checklist for autism in toddlers: a follow-up study investigating the early detection of autism spectrum disorders

Autism spectrum disorders (ASD) often go undetected in toddlers. The Modified Checklist for Autism in Toddlers (M-CHAT) was used to screen 3,793 children aged 16-30 months from low- and high-risk sources; screen positive cases were diagnostically evaluated. Rescreening was performed on 1,416 children aged 42-54 months. Time 1 Positive Predictive Value (PPV) was .36 for the initial screening and .74 for the screening plus follow-up telephone interview; values were similar for Time2 PPV. When separating referral sources, PPV was low for the low-risk sample but acceptable with the followup telephone interview. Children with ASD from the low-risk and high-risk samples were highly similar. Results indicate that the M-CHAT continues to be a promising instrument for the early detection of ASD.

Screening for autism in older and younger toddlers with the Modified Checklist for Autism in Toddlers

The Modified Checklist for Autism in Toddlers (M—CHAT) was used to screen younger (16—23 months) versus older (24—30 months) high- and low-risk toddlers. Refusal rates for follow-up interview showed no group differences, but parents of younger/low-risk children were more likely to refuse evaluation than parents of high-risk children. PPP for an ASD diagnosis was: younger/high-risk 0.79, older/high-risk 0.74, younger/low-risk 0.28, and older/low-risk 0.61, with PPP differing by age within the low-risk group. Most of the children in all groups, however, were diagnosed with a developmental disorder. Symptom severity generally did not differ among groups. Cognitive and adaptive measures showed minimal group differences. Therefore, older and younger toddlers had similar symptomatology and developmental delays; PPP for ASD is better at 24 than 18 months for low-risk children; however, these children are still highly likely to show a developmental disorder. Clinical decision making should balance early identification against the lower specificity of M—CHAT screening for the younger/low-risk group.

Autism in infants: an update

Although autism is a disorder of very early onset, knowledge on how it is first expressed in infancy has, until recently, remained limited. In recent years new strategies of research, including prospective studies, have substantially increased our knowledge regarding autism in infants. Research findings have suggested the very early emergence of significant differences in social information processes. In addition to having important implications for research, these findings also offer new opportunities for screening and early identification and, hopefully, for improved outcome.

Differentiating between autism spectrum disorders and other developmental disabilities in children who failed a screening instrument for ASD

This study compared behavioral presentation of toddlers with autistic spectrum disorders (ASD) and toddlers with global developmental delay (DD) or developmental language disorder (DLD) who display some characteristics of ASD using the diagnostic algorithm items from the Autism Diagnostic Observation Schedule, Generic (ADOS), the Childhood Autism Rating Scale (CARS), and Modified Checklist for Autism in Toddlers (M-CHAT). To date, 195 children have failed the M-CHAT and have been diagnosed with ASD, DD or DLD. Children with ASD had prominent and consistent impairments in socialization skills, especially joint attention skills and were more impaired in some aspects of communication, play, and sensory processing. Children with ASD and children with DD/DLD shared common features, but certain behavioral markers differentiated the two groups.

"Listen my children and you shall hear": auditory preferences in toddlers with autism spectrum disorders

PURPOSE

This study tests the hypothesis that toddlers with autism spectrum disorders (ASD) will show differences from contrast groups in preferences for attending to speech.

METHOD

This study examined auditory preferences in toddlers with ASD and matched groups of (a) typical age-mates, (b) age-mates with nonautistic developmental disabilities, and (c) younger children matched for language age. The experimental procedure measured time spent oriented to auditory stimuli that were created to exemplify language patterns that had been studied in typically developing infants.

RESULTS

Findings suggest that toddlers with ASD show a reduced preference for child-directed speech, compared with typical age-mates, but few differences from children with nonautistic developmental disorders. Correlational analysis revealed that time spent listening to child-directed speech by children with ASD was related to their concurrent receptive language ability as well as to receptive language abilities 1 year later. This relationship did not hold for the other groups.

CONCLUSION

The present study supports the hypothesis that children with ASD perform differently from typical peers in auditory preference paradigms and that performance in these tasks is related to concurrent and later language development.

Impairments in monkey and human face recognition in 2-year-old toddlers with Autism Spectrum Disorder and Developmental Delay

Face recognition impairments are well documented in older children with Autism Spectrum Disorders (ASD); however, the developmental course of the deficit is not clear. This study investigates the progressive specialization of face recognition skills in children with and without ASD. Experiment 1 examines human and monkey face recognition in 2-year-old children with ASD, matched for nonverbal mental age (NVMA) with developmentally delayed (DD) children, and typically developing children (TD), using the Visual Paired Comparison (VPC) paradigm. Results indicate that, consistent with the other-species effect, TD controls show enhanced recognition of human but not monkey faces; however, neither the ASD nor the DD group show evidence of face recognition regardless of the species. Experiment 2 examines the same question in a group of older 3- to 4-year-old developmentally disabled (ASD and DD) children as well as in typical controls. In this experiment, both human and monkey faces are recognized by all three groups. The results of Experiments 1 and 2 suggest that difficulties in face processing, as measured by the VPC paradigm, are common in toddlers with ASD as well as DD, but that these deficits tend to disappear by early preschool age. In addition, the experiments show that higher efficacy of incidental encoding and recognition of facial identity in a context of passive exposure is positively related to nonverbal cognitive skills and age, but not to overall social interaction skills or greater attention to faces exhibited in naturalistic contexts.

Placental trophoblast inclusions in autism spectrum disorder

BACKGROUND

Microscopic examination of placental tissue may provide a route to assessing risk and understanding underlying biology of autism.

METHODS

Occurrence of a distinctive microscopic placental morphological abnormality, the trophoblast inclusion, was assessed using archived placental tissue. The rate of occurrence of trophoblast inclusion-positive slides observed for 13 individuals with autism spectrum disorder (ASD) was compared to the rate in an anonymous consecutive birth cohort.

RESULTS

The occurrence of inclusion positive slides was significantly greater in the ASD group compared to the control group (6/27 slides, 22.2% vs. 12/154, 7.8%; Fisher Exact Test, two-tailed p = .033; relative risk 2.85). The proportion of positive cases was also greater in the ASD group (5/13 cases, 38.5% vs. 8/61, 13.1%; Fisher Exact, two-tailed p = .044; relative risk 2.93). Behavioral severity scores did not differ across groups of inclusion positive (N = 4) and negative (N = 8) ASD individuals.

CONCLUSIONS

Although probably not functionally detrimental or causative, the greater occurrence of placental trophoblast inclusions observed in ASD individuals may reflect altered early developmental processes. Further research is required to replicate the basic finding, to understand the basis for the trophoblastic abnormality, and to determine the utility of the measure in early detection of ASD.

Autism spectrum disorder in the second year: stability and change in syndrome expression

OBJECTIVES

Increasing numbers of young children referred for a differential diagnosis of autism spectrum disorders (ASD) necessitates better understanding of the early syndrome expression and the utility of the existing state-of-the art diagnostic methods in this population.

METHOD

Out of 31 infants under the age of 2 years referred for a differential diagnosis, 19 were diagnosed with autism, and 9 with pervasive developmental disorder - not otherwise specified (PDD-NOS) when reassessed at 3 years. We examined 1) the symptoms of ASD in the second year and changes in the syndrome expression by the age of three; 2) relationship between expert-assigned clinical diagnosis and diagnostic classification based on Autism Diagnostic Observation Schedule-Generic (ADOS-G) and Autism Diagnostic Interview-Revised (ADI-R) in the second year; 3) the relationship between direct observation and parental report of ASD symptoms.

RESULTS

Symptoms of autism and PDD-NOS in the second year were pronounced and stability of the clinical diagnosis was high. The agreement between clinician-assigned autism but not PDD-NOS diagnosis and the ADOS-G was high. However, sensitivity of the ADI-R diagnostic classification of autism was poor. Comparison of concurrent parental report and direct observation revealed discrepancies in severity ratings of key dyadic social behaviors. Changes in communication reflected acquisition of language accompanied by the emergence of unusual language characteristics. Symptoms of social dysfunction were relatively stable over time, and so was the severity of stereotyped behaviors.

CONCLUSIONS

The study provides support for stability of clinical diagnosis and syndrome expression in the second year and highlights advantages and limitations of the ADI-R and ADOS-G for diagnosing and documenting symptoms of ASD in infants.

Parental Recognition of Developmental Problems in Toddlers with Autism Spectrum Disorders

Symptoms of Autism Spectrum Disorders (ASD) begin to manifest during the first 2 years; there is limited evidence regarding type and timing of symptom onset. We examined factors related to parental age of recognition (AOR) of early abnormalities and the association between AOR and diagnosis and levels of functioning at 2 and 4 years in 75 toddlers with ASD. Results suggest significant differences between autism and PDD-NOS in the AOR and type of first concerns. Early social and motor delays as well as maternal age was associated with AOR. Later AOR was associated with poorer social-communicative and nonverbal cognitive functioning at 2 and 4. The findings are discussed in a context of identifying distinct developmental trajectories within the autism spectrum.

Automatic attention cueing through eye movement in 2-year-old children with autism

Automatic attention cueing by perceived changes in gaze direction was studied in 2-year-old children with autism and typically developing (TD) controls using a visual attention cueing paradigm. In Experiments 1 and 2 the cue consisted of an eye movement (Eyes) and a nonbiological movement (SimEyes), respectively. The results suggest that visual attention in children with autism and their TD counterparts is cued by perceived eye movement. Thus, although in naturalistic situations toddlers with autism do not follow the gaze of others, they are sensitive to directional cues inherent in eye movement. Cue-specific differences in performance related to the level of engagement and cue-processing time may suggest reliance on different underlying strategies for gaze processing in autism.

The development of visual expectations in the first year

The development of expectations was investigated by using the Visual Expectations Procedure. In Experiment 1, 128 infants aged 6-, 9-, and 12-months-old saw two 40-trial sequences of a videotaped mechanical toy appearing in various locations. The sequences represented an alternation pattern (i.e., ABAB) or a complex pivot pattern (i.e., ABCBABCB). In Experiment 2, 76 infants aged 4-, 8-, and 12-months-old saw either a left-right alternation or a top-bottom alternation. Reaction time improved and the percentage of anticipations increased between 6 and 9 months in Experiment 1 and between 4 and 8 months in Experiment 2 but not thereafter. Anticipations for the pivot sequence and for younger infants on both sequences were often incorrect (i.e., gaze shifts occurred before stimulus onset but were not directed toward the upcoming stimulus). We conclude that young infants have expectations that reflect some degree of general or procedural knowledge, but it is not clear that this behavior implies specific, articulated expectations about upcoming events.

Information processing and developmental assessments in 3-month-old infants exposed prenatally to cocaine

OBJECTIVE

To determine the effect of prenatal cocaine exposure on 3-month infant information processing and developmental assessments.

METHODS

One hundred and eight infants, 61 cocaine-exposed and 47 controls, participated at 3 months of age in an infant-control habituation and novelty responsiveness procedure and in a developmental assessment using the Bayley Scales of Infant Development both administered by experimenters blind to the drug exposure status of the infant.

RESULTS

Compared to the non-drug-exposed group, infants exposed prenatally to cocaine were significantly more likely to fail to start the habituation procedure and, for those who did, significantly more likely to react with irritability early in the procedure. The majority of infants in both groups reached the habituation criterion, and among those who did there were no significant differences between cocaine and non-cocaine-exposed infants in habituation or in recovery to a novel stimulus. Infants who were cocaine-exposed showed comparatively depressed performance on the motor (Psychomotor Developmental Index) but not the mental (Mental Developmental Index (MDI)) scales of the Bayley. These results obtained for habituation and Bayley MDI controlling for both perinatal and sociodemographic factors.

CONCLUSIONS

Differences in reactivity to novelty but not in information processing between cocaine-exposed and non-cocaine-exposed infants suggest that the effects of prenatal cocaine exposure may be on arousal and attention regulation rather than early cognitive processes.