Atypical Developmental Trajectories Research Articles

Motor functioning, exploration, visuospatial cognition and language development in preschool children with autism

In order to understand typical and atypical developmental trajectories it is important to assess how strengths or weaknesses in one domain may be affecting performance in other domains. This study examined longitudinal relations between early fine motor functioning, visuospatial cognition, exploration, and language development in preschool children with ASD and children with other developmental delays/disorders. The ASD group included 63 children at T1 (Mage=27.10 months, SD=8.71) and 46 children at T2 (Mage=45.85 months, SD=7.16). The DD group consisted of 269 children at T1 (Mage=17.99 months, SD=5.59), and 121 children at T2 (Mage=43.51 months, SD=3.81). A subgroup nested within the total sample was randomly selected and studied in-depth on exploratory behavior. This group consisted of 50 children, 21 children with ASD (Mage=27.57, SD=7.09) and 29 children with DD (Mage=24.03 months, SD=6.42). Fine motor functioning predicted language in both groups. Fine motor functioning was related to visuospatial cognition in both groups and related to object exploration, spatial exploration, and social orientation during exploration only in the ASD group. Visuospatial cognition and all exploration measures were related to both receptive and expressive language in both groups. The findings are in line with the embodied cognition theory, which suggests that cognition emerges from and is grounded in the bodily interactions of an agent with the environment. This study emphasizes the need for researchers and clinicians to consider cognition as emergent from multiple interacting systems.

Atypical development of white matter microstructure of the corpus callosum in males with autism: a longitudinal investigation.

BackgroundThe corpus callosum is the largest white matter structure in the brain, and it is the most consistently reported to be atypical in diffusion tensor imaging studies of autism spectrum disorder. In individuals with typical development, the corpus callosum is known to undergo a protracted development from childhood through young adulthood. However, no study has longitudinally examined the developmental trajectory of corpus callosum in autism past early childhood.MethodsThe present study used a cohort sequential design over 9 years to examine age-related changes of the corpus callosum in 100 males with autism and 56 age-matched males with typical development from early childhood (when autism can first be reliably diagnosed) to mid-adulthood (after development of the corpus callosum has been completed) (3 to 41 years of age).ResultsThe group with autism demonstrated a different developmental trajectory of white matter microstructure in the anterior corpus callosum’s (genu and body) fractional anisotropy, which suggests atypical brain maturation in these regions in autism. When analyses were broken down by age group, atypical developmental trajectories were present only in the youngest participants (10 years of age and younger). Significant main effects for group were found in terms of decreased fractional anisotropy across all three subregions of the corpus callosum (genu, body, and splenium) and increased mean diffusivity, radial diffusivity, and axial diffusivity in the posterior corpus callosum.ConclusionsThese longitudinal results suggest atypical early childhood development of the corpus callosum microstructure in autism that transitions into sustained group differences in adolescence and adulthood. This pattern of results provides longitudinal evidence consistent with a growing number of published studies and hypotheses regarding abnormal brain connectivity across the life span in autism.Electronic supplementary materialThe online version of this article (doi:10.1186/s13229-015-0001-8) contains supplementary material, which is available to authorized users.

Developmental plateau in visual object processing from adolescence to adulthood in autism

A lack of typical age-related improvement from adolescence to adulthood contributes to face recognition deficits in adults with autism on the Cambridge Face Memory Test (CFMT). The current studies examine if this atypical developmental trajectory generalizes to other tasks and objects, including parts of the face. The CFMT tests recognition of whole faces, often with a substantial delay. The current studies used the immediate memory (IM) task and the parts-whole face task from the Let’s Face It! battery, which examines whole faces, face parts, and cars, without a delay between memorization and test trials. In the IM task, participants memorize a face or car. Immediately after the target disappears, participants identify the target from two similar distractors. In the part-whole task, participants memorize a whole face. Immediately after the face disappears, participants identify the target from a distractor with different eyes or mouth, either as a face part or a whole face.Results indicate that recognition deficits in autism become more robust by adulthood, consistent with previous work, and also become more general, including cars. In the IM task, deficits in autism were specific to faces in childhood, but included cars by adulthood. In the part-whole task, deficits in autism became more robust by adulthood, including both eyes and mouths as parts and in whole faces. Across tasks, the deficit in autism increased between adolescence and adulthood, reflecting a lack of typical improvement, leading to deficits with non-face stimuli and on a task without a memory delay. These results suggest that brain maturation continues to be affected into adulthood in autism, and that the transition from adolescence to adulthood is a vulnerable stage for those with autism.

Intact Facial Adaptation in Autistic Adults

Adaptation paradigms seek to bias subsequently viewed stimuli through prolonged exposure to an adapting stimulus, thereby giving rise to an aftereffect. Recent experiments have found that children with autism spectrum disorders (ASD) show reduced facial aftereffects, prompting some researchers to speculate that all individuals with ASD exhibit deficient facial adaptation. However, caution is required when generalizing findings from samples of children with ASD to the wider ASD population. The reduced facial aftereffects seen in child samples may instead reflect delayed or atypical developmental trajectories, whereby individuals with ASD are slower to develop adaptive mechanisms. In the present study, two experiments were conducted to determine whether high-functioning adults with ASD also show diminished aftereffects for facial identity and expression. In Experiment 1, using a procedure that minimized the contribution of low-level retinotopic adaptation, we observed substantial aftereffects comparable to those seen in matched controls, for both facial identity and expression. A similar pattern of results was seen in Experiment 2 using a revised procedure that increased the contribution of retinotopic adaptation to the facial aftereffects observed. That adults with autism can show robust facial aftereffects raises the possibility that group differences are seen only at particular points during development, and may not be a lifelong feature of the condition.

The development of stranger fear in infancy and toddlerhood: normative development, individual differences, antecedents, and outcomes

Despite implications that stranger fear is an important aspect of developing behavioral inhibition, a known risk factor for anxiety, normative and atypical developmental trajectories of stranger fear across infancy and toddlerhood remain understudied. We used a large, longitudinal data set (N = 1285) including multi-trait, multi-method assessments of temperament to examine the normative course of development for stranger fear and to explore the possibility that individual differences exist in trajectories of stranger fear development between 6 and 36 months of age. A latent class growth analysis suggested four different trajectories of stranger fear during this period. Stable, high levels of stranger fear over time were associated with poorer RSA suppression at 6 months of age. Rates of concordance in trajectory-based class membership for identical (monozygotic) and fraternal (dizygotic) twins, along with associations between atypical stranger fear development and greater anxiety-related maternal characteristics, suggested that individual differences in developmental trajectories of stranger fear may be heritable. Importantly, trajectories of stranger fear during infancy and toddlerhood were linked to individual differences in behavioral inhibition, with chronically high levels of stranger fear and sharp increases in stranger fear over time related to greater levels of inhibition than other developmental trajectories.

Cognitive Science, Development, and Psychopathology Typical and Atypical Developmental Trajectories of Attention

Cognitive Science, Development, and Psychopathology Typical and Atypical Developmental Trajectories of Attention

Cognitive Science, Development, and Psychopathology Typical and Atypical Developmental Trajectories of Attention

Cognitive Science, Development, and Psychopathology Typical and Atypical Developmental Trajectories of Attention

Intervention for Infants at Risk of Developing Autism: A Case Series

Theory and evidence suggest the potential value of prodromal intervention for infants at risk of developing autism. We report an initial case series (n=8) of a parent-mediated, video-aided and interaction-focused intervention with infant siblings of autistic probands, beginning at 8-10months of age. We outline the theory and evidence base behind this model and present data on feasibility, acceptability and measures ranging from parent-infant social interaction, to infant atypical behaviors, attention and cognition. The intervention proves to be both feasible and acceptable to families. Measurement across domains was successful and on larger samples promise to be an effective test of whether such an intervention in infancy will modify emergent atypical developmental trajectories in infants at risk for autism.

Quality of interaction between at‐risk infants and caregiver at 12–15 months is associated with 3‐year autism outcome

Recent models of the early emergence of autism spectrum disorder (ASD) propose that infant intrinsic risk susceptibilities in behaviour may be amplified by interaction within the early social environment into an increasingly atypical developmental trajectory. This study examines whether 6- and 12-month parent-infant interactions in at-risk siblings differ from those with low-risk and whether--in at-risk siblings--such interactions predict later 3-year classification of ASD or no ASD. Within the British Autism Study of Infant Siblings (BASIS), 6-min videotaped episodes of parent-infant free play in infants at 6-10 months (45 at-risk siblings and 47 low-risk siblings) and 12-15 months (43 at-risk siblings and 48 low-risk siblings) in a laboratory setting were rated on the Manchester Assessment of Caregiver-Infant Interaction (MACI), blind to participant information. Standard tests were administered for concurrent behavioural signs of ASD features and developmental level. Systematic consensus diagnostic classification of ASD was made at 3 years for the at-risk siblings. Parent nondirectiveness and sensitive responsiveness differed in relation to ASD/risk status (at-risk ASD, at-risk no-ASD and low-risk) at both 6 and 12 months. At 6 months, infant liveliness was lower in the at-risk groups; at 12 months, infant attentiveness to parent and positive affect were lower in the at-risk group later diagnosed with ASD. Dyadic mutuality and intensity of engagement showed a group effect at 12 months. Dyadic mutuality, infant positive affect and infant attentiveness to parent at 12 months (but not 6 months) predicted 3-year ASD outcome, whereas infant ASD-related behavioural atypicality did not. This is the first prospective evidence that early dyadic interaction between at-risk infants and their parents is associated with later diagnostic outcome in ASD. Possible explanations for these findings and their theoretical implications are considered.

Balance function in patients with Williams syndrome

Impaired control of balance has been described in Williams syndrome (WS). The aim of this study was to investigate balance function by means of clinical and instrumental tests in order to measure postural sway in people with WS in an objective way. 23 WS patients (11 males, 12 females, mean age 17.52±8.33 years) and 23 healthy subjects (11 males, 12 females, mean age 17.74±8.93 years) performed static posturography with eyes open and closed, on a firm surface and on foam pads. The WS patients had higher mean length, velocity and surface values than controls under all of the test conditions, and their length and surface values were significantly higher in the eyes open test. The cognitive abilities of the WS patients were not related to their stabilometric performance. The greatest differences between the WS patients and the controls were found mainly in the older subjects. WS patients are more unstable than healthy subjects of the same age, particularly when they use visual information to maintain their balance: i.e. under conditions of normal everyday life. Possible explanations may be the ophthalmologic problems and the visuospatial difficulties attributed to a neural processing abnormality involving the dorsal stream impairment model. The balance function of WS patients is different from that of normal developing subjects, especially after adolescence when postural control is generally complete. This suggests an atypical developmental trajectory.

Learning without representational change: development of numerical estimation in individuals with Williams syndrome

Experience engenders learning, but not all learning involves representational change. In this paper, we provide a dramatic case study of the distinction between learning and representational change. Specifically, we examined long- and short-term changes in representations of numeric magnitudes by asking individuals with Williams syndrome (WS) and typically developing (TD) children to estimate the position of numbers on a number line. As with TD children, accuracy of WS children's numerical estimates improved with age (Experiment 1) and feedback (Experiment 2). Both long- and short-term changes in estimates of WS individuals, however, followed an atypical developmental trajectory: as TD children gained in age and experience, increases in accuracy were accompanied by a logarithmic-to-linear shift in estimates of numerical magnitudes, whereas in WS individuals, accuracy increased but logarithmic estimation patterns persisted well into adulthood and after extensive training. These findings suggest that development of numerical estimation in WS is both arrested and atypical.

Age-related changes in visual and auditory sustained attention in preschool-aged children

Objective: The development of sustained attention in the preschool years is not yet fully understood. Delineating age-related changes of attentional proficiencies and deficiencies is important for understanding atypical developmental trajectories, specifically in neurodevelopmental disorders that are characterized by attentional difficulties. The objective of the current study was to develop preschool-appropriate measures for assessing sustained attention and to chart developmental changes in attention in early childhood. Method: Using adapted computerized paradigms, the present study investigated age-related changes in visual and auditory sustained attention in seventy typically developing children aged 3 to 6 years. Results: The results indicated that similar age-related gains in performance emerged across both visual and auditory attention tasks. Conclusion: The findings suggest that the adapted measures developed in this study are sensitive enough to capture developmental variations in attention performance.

Diffusion tensor imaging in autism spectrum disorder: a review.

White matter tracts of the brain allow neurons and neuronal networks to communicate and function with high efficiency. The aim of this review is to briefly introduce diffusion tensor imaging methods that examine white matter tracts and then to give an overview of the studies that have investigated white matter integrity in the brains of individuals with autism spectrum disorder (ASD). From the 48 studies we reviewed, persons with ASD tended to have decreased fractional anisotropy and increased mean diffusivity in white matter tracts spanning many regions of the brain but most consistently in regions such as the corpus callosum, cingulum, and aspects of the temporal lobe. This decrease in fractional anisotropy was often accompanied by increased radial diffusivity. Additionally, the review suggests possible atypical lateralization in some white matter tracts of the brain and a possible atypical developmental trajectory of white matter microstructure in persons with ASD. Clinical implications and future research directions are discussed.

Developmental Changes in Visual and Auditory Inhibition in Early Childhood

The development of executive functions in the preschool years is not fully understood. Although there exists a large body of research investigating the maturation of executive functioning in school‐aged children, little is known about the emergence of such skills, in particular inhibition, among preschool‐aged children. Understanding developmental changes of inhibition proficiencies and deficiencies early in childhood is important for charting typical and atypical developmental trajectories. Using an adapted computerized paradigm, the present study examined age‐related changes in visual and auditory inhibition in 68 typically developing children aged 3 to 6 years. The results indicated that although similar age‐related gains in performance occurred across both visual and auditory inhibition tasks, certain modality‐specific differences emerged in terms of accuracy and reaction time. These results suggest that the newly adapted measures used are sensitive enough to capture developmental variations in inhibition. Copyright © 2012 John Wiley & Sons, Ltd.

Parent–infant interaction in infant siblings at risk of autism

Recent models of the early emergence of autism spectrum disorder (ASD) propose an interaction between risk susceptibility and the infant's social environment, resulting in a progressively atypical developmental trajectory. The infant's early social environmental experience consists mostly of interaction with caregivers, yet there has been little systematic study of early parent-infant interaction in infants at risk of ASD. This study examined the global characteristics of parent-infant interaction in 6- to 10-month-old infants with an older sibling diagnosed with ASD (at-risk sibs), in comparison with a group of infants with no family history of ASD (low-risk sibs). As part of the British Autism Study of Infant Siblings (BASIS), 6-min videotaped unstructured play interactions of mother-infant dyads (45 at-risk sibs and 47 low-risk sibs) were rated on global aspects of parent-infant interaction, blind to participant information. Differences in global characteristics of interaction were observed in both infant and parent contributions in the at-risk group compared to low-risk controls. In analyses adjusted for age and developmental level, at-risk sib infants were less lively, and their parents showed higher directiveness, and lower sensitive responding (as a trend after adjustment). Level of infant liveliness was independent of other interactive behaviour. Consistent with reports in previous literature in older children with autism and in other neurodevelopmental disorders, our findings may suggest that infants at genetic risk are exposed to a more directive interactive style relatively early in infancy. We discuss possible explanations for these findings and implications for further developmental study and intervention.

Differences in white matter reflect atypical developmental trajectory in autism: A Tract-based Spatial Statistics study

Autism is a neurodevelopmental disorder in which white matter (WM) maturation is affected. We assessed WM integrity in 16 adolescents and 14 adults with high-functioning autism spectrum disorder (ASD) and in matched neurotypical controls (NT) using diffusion weighted imaging and Tract-based Spatial Statistics. Decreased fractional anisotropy (FA) was observed in adolescents with ASD in tracts involved in emotional face processing, language, and executive functioning, including the inferior fronto-occipital fasciculus and the inferior and superior longitudinal fasciculi. Remarkably, no differences in FA were observed between ASD and NT adults.We evaluated the effect of age on WM development across the entire age range. Positive correlations between FA values and age were observed in the right inferior fronto-occipital fasciculus, the left superior longitudinal fasciculus, the corpus callosum, and the cortical spinal tract of ASD participants, but not in NT participants.Our data underscore the dynamic nature of brain development in ASD, showing the presence of an atypical process of WM maturation, that appears to normalize over time and could be at the basis of behavioral improvements often observed in high-functioning autism.

Atypical development of resting respiratory sinus arrhythmia in children at high risk for depression

Compromised respiratory sinus arrhythmia (RSA, i.e., low cardiac vagal control) frequently characterizes clinically depressed adults and also has been detected in infants of depressed mothers; however, its existence has not been established in older at-risk offspring. We investigated developmental patterns of RSA in a sample of 163 5- to 14-year-old children, who were either at high risk for depression (due to having a parent with a childhood-onset mood disorder) or low-risk for depression. We hypothesized that high-risk children have lower resting RSA than do low-risk children, which could reflect atypical developmental trajectories. Children's RSA was assessed during resting baseline periods on multiple occasions, typically 1-year apart. Linear growth modeling indicated a group by age interaction. Low-risk children (but not the high-risk children) exhibited a significantly increasing trajectory in resting RSA with age. Mood disorders in offspring did not account for the Group X Age interaction effect. Our study provides new evidence that children at high risk for depression have an atypical developmental trajectory of RSA across late childhood.

Atypical developmental trajectory of functionally significant cortical areas in children with chromosome 22q11.2 deletion syndrome

Chromosome 22q11.2 deletion syndrome (22q11.2DS) is a neurogenetic disorder associated with neurocognitive impairments. This article focuses on the cortical gyrification changes that are associated with the genetic disorder in 6-15-year-old children with 22q11.2DS, when compared with a group of age-matched typically developing (TD) children. Local gyrification index (lGI; Schaer et al. [2008]: IEEE Trans Med Imaging 27:161-170) was used to characterize the cortical gyrification at each vertex of the pial surface. Vertex-wise statistical analysis of lGI differences between the two groups revealed cortical areas of significant reduction in cortical gyrification in children with 22q11.2DS, which were mainly distributed along the medial aspect of each hemisphere. To gain further insight into the developmental trajectory of the cortical gyrification, we examined age as a factor in lGI changes over the 6-15 years of development, within and across the two groups of children. Our primary results pertaining to the developmental trajectory of cortical gyrification revealed cortical regions where the change in lGI over the 6-15 years of age was significantly modulated by diagnosis, implying an atypical development of cortical gyrification in children with 22q11.2DS, when compared with the TD children. Significantly, these cortical areas included parietal structures that are associated, in typical individuals, with visuospatial, attentional, and numerical cognition tasks in which children with 22q11.2DS show impairments.

Mechanisms of developmental regression in autism and the broader phenotype: A neural network modeling approach.

Loss of previously established behaviors in early childhood constitutes a markedly atypical developmental trajectory. It is found almost uniquely in autism and its cause is currently unknown (Baird et al., 2008). We present an artificial neural network model of developmental regression, exploring the hypothesis that regression is caused by overaggressive synaptic pruning and identifying the mechanisms involved. We used a novel population-modeling technique to investigate developmental deficits, in which both neurocomputational parameters and the learning environment were varied across a large number of simulated individuals. Regression was generated by the atypical setting of a single pruning-related parameter. We observed a probabilistic relationship between the atypical pruning parameter and the presence of regression, as well as variability in the onset, severity, behavioral specificity, and recovery from regression. Other neurocomputational parameters that varied across the population modulated the risk that an individual would show regression. We considered a further hypothesis that behavioral regression may index an underlying anomaly characterizing the broader autism phenotype. If this is the case, we show how the model also accounts for several additional findings: shared gene variants between autism and language impairment (Vernes et al., 2008); larger brain size in autism but only in early development (Redcay & Courchesne, 2005); and the possibility of quasi-autism, caused by extreme environmental deprivation (Rutter et al., 1999). We make a novel prediction that the earliest developmental symptoms in the emergence of autism should be sensory and motor rather than social and review empirical data offering preliminary support for this prediction.

Reconsidering the impact of preterm birth on language outcome

Background Since preterm birth is associated with a constellation of pre-, peri- and post-natal risk factors, we hypothesised that prematurity may continue to impact the development of linguistic abilities even up to the end of the preschool years and beyond, giving rise to an atypical developmental trajectory. The study tested this hypothesis at six years of age, investigating whether language is affected by preterm birth and how different linguistic abilities are interrelated. Method Seventy monolingual Italian preterms and 34 age-matched controls were recruited. Linguistic abilities (vocabulary, grammar, and phonological awareness) as well as general cognitive developmental levels were measured . Results No general cognitive delay emerged, but less developed abilities in vocabulary, grammar, and phonological awareness were found in preterms compared to fullterms. Moreover, the relations among the different linguistic competences differed across groups. Conclusions Our study shows that even without brain damage, preterm birth continues to affect linguistic development up to the end of the preschool years, and probably beyond, highlighting a continuity between pre- and peri-natal life and subsequent development, and pointing to an atypical developmental trajectory in this population compared to fullterms (different rates of development, different strategies employed, and differences in the relationships among linguistic abilities).