897 research outputs found

    Disengagement of visual attention in infancy is associated with emerging autism in toddlerhood

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    Background: Early emerging characteristics of visual orienting have been associated with a wide range of typical and atypical developmental outcomes. In the current study, we examined the development of visual disengagement in infants at risk for autism. Methods: We measured the efficiency of disengaging from a central visual stimulus to orient to a peripheral one in a cohort of 104 infants with and without familial risk for autism by virtue of having an older sibling with autism. Results: At 7 months of age, disengagement was not robustly associated with later diagnostic outcomes. However, by 14 months, longer latencies to disengage in the subset of the risk group later diagnosed with autism was observed relative to other infants at risk and the low-risk control group. Moreover, between 7 months and 14 months, infants who were later diagnosed with autism at 36 months showed no consistent increases in the speed and flexibility of visual orienting. However, the latter developmental effect also characterized those infants who exhibited some form of developmental concerns (but not meeting criteria for autism) at 36 months. Conclusions: Infants who develop autism or other developmental concerns show atypicality in the development of visual attention skills from the first year of life

    Parent-mediated intervention versus no intervention for infants at high risk of autism: a parallel, single-blind, randomised trial

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    - Background: Risk markers for later autism identified in the first year of life present plausible intervention targets during early development. We aimed to assess the effect of a parent-mediated intervention for infants at high risk of autism on these markers. - Methods: We did a two-site, two-arm assessor-blinded randomised controlled trial of families with an infant at familial high risk of autism aged 7–10 months, testing the adapted Video Interaction to Promote Positive Parenting (iBASIS-VIPP) versus no intervention. Families were randomly assigned to intervention or no intervention groups using a permuted block approach stratified by centre. Assessors, but not families or therapists, were masked to group assignment. The primary outcome was infant attentiveness to parent. Regression analysis was done on an intention-to-treat basis. This trial is registered with ISCRTN Registry, number ISRCTN87373263. - Findings: We randomly assigned 54 families between April 11, 2011, and Dec 4, 2012 (28 to intervention, 26 to no intervention). Although CIs sometimes include the null, point estimates suggest that the intervention increased the primary outcome of infant attentiveness to parent (effect size 0·29, 95% CI −0·26 to 0·86, thus including possibilities ranging from a small negative treatment effect to a strongly positive treatment effect). For secondary outcomes, the intervention reduced autism-risk behaviours (0·50, CI −0·15 to 1·08), increased parental non-directiveness (0·81, 0·28 to 1·52), improved attention disengagement (0·48, −0·01 to 1·02), and improved parent-rated infant adaptive function (χ2[2] 15·39, p=0·0005). There was a possibility of nil or negative effect in language and responsivity to vowel change (P1: ES–0·62, CI −2·42 to 0·31; P2: −0·29, −1·55 to 0·71). - Interpretation: With the exception of the response to vowel change, our study showed positive estimates across a wide range of behavioural and brain function risk-markers and developmental outcomes that are consistent with a moderate intervention effect to reduce the risk for later autism. However, the estimates have wide CIs that include possible nil or small negative effects. The results are encouraging for development and prevention science, but need larger-scale replication to improve precision

    Gaze following, gaze reading, and word learning in children at-risk for autism

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    We investigated gaze following abilities as a prerequisite for word learning, in a population expected to manifest a wide range of individual variability – children with a family history of autism. Three-year-olds with or without a family history of autism took part in a word-learning task that required following gaze to find the correct referent of a novel word. Using an eye-tracker to monitor children’s gaze behavior we show that the ability to follow an adult’s gaze was necessary but not sufficient for successful word learning. Those children that had poor social and communicative skills could follow gaze to the correct object, but did not then learn the word associated with that object. These findings shed light on the conditions that lead to successful or less successful word learning in typical and atypical populations

    Reduced orienting to audiovisual synchrony in infancy predicts autism diagnosis at 3 years of age

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    Background: Effective multisensory processing develops in infancy and is thought to be important for the perception of unified and multimodal objects and events. Previous research suggests impaired multisensory processing in autism, but its role in the early development of the disorder is yet uncertain. Here, using a prospective longitudinal design, we tested whether reduced visual attention to audiovisual synchrony is an infant marker of later-emerging autism diagnosis. Methods: We studied 10-month-old siblings of children with autism using an eye tracking task previously used in studies of preschoolers. The task assessed the effect of manipulations of audiovisual synchrony on viewing patterns while the infants were observing point light displays of biological motion. We analyzed the gaze data recorded in infancy according to diagnostic status at 3 years of age (DSM-5). Results: Ten-month-old infants who later received an autism diagnosis did not orient to audiovisual synchrony expressed within biological motion. In contrast, both infants at low-risk and high-risk siblings without autism at follow-up had a strong preference for this type of information. No group differences were observed in terms of orienting to upright biological motion. Conclusions: This study suggests that reduced orienting to audiovisual synchrony within biological motion is an early sign of autism. The findings support the view that poor multisensory processing could be an important antecedent marker of this neurodevelopmental condition. Keywords: Autism spectrum disorder; infancy; multisensory processing; biological motion; biomarker; scientific replication

    Aging behavior of intercritically quenched ductile iron

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    Although extensive aging and strain aging (bake hardening, BH) studies have been carried out on dual-phase steels, the aging behavior of the dual matrix structure (DMS) ductile iron (DI), as a potential way to improve its mechanical properties, has not been addressed until now. This research was designed to study the aging behavior of DI with a ferrite-martensite matrix structure. DMS-DI with a martensite volume fraction of 30% was produced by intercritical austenitizing at 785 ◦C followed by quenching in water to room temperature. Aging treatments were carried out without prestraining at aging temperatures of 140, 170, and 220 ◦C for 2–10,000 min. DMS-DI was investigated by light optical microscopy (LOM) for unaged samples and scanning electron microscopy (SEM) for selected samples after aging treatments. The effect of aging conditions on the mechanical properties were investigated. Microhardness measurements for ferrite and martensite were also examined as a function of aging conditions. The increase in yield strength due to aging was determined. The results indicate that the aging conditions have a small effect on the ultimate tensile strength UTS. It is shown that the yield strength increased to a maximum value of 45 MPa (~11% increase) after aging for particular time, which is found to be dependent on the aging temperature. The peak aging response is followed by a decrease in yield strength, which is observed to be attributed to martensite tempering as confirmed by microhardness measurements

    Atypical modulation of face-elicited saccades in autism spectrum disorder in a double-step saccade paradigm

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    Atypical development of face processing is a major characteristic in autism spectrum disorder (ASD), which could be due to atypical interactions between subcortical and cortical face processing. The current study investigated the saccade planning towards faces in ASD. Seventeen children with ASD and 17 typically developing (TD) children observed a pair of upright or inverted face configurations flashed sequentially in two different spatial positions. The reactive saccades of participants were recorded by eye-tracking. The results did not provide evidence of overall impairment of subcortical route in ASD, However, the upright, but not the inverted, face configuration modulated the frequency of vector sum saccades (an index of subcortical control) in TD, but not in ASD. The current results suggest that children with ASD do not have overall impairment of the subcortical route, but the subcortical route may not be specialized to face processing

    Precursors to social and communication difficulties in infants at-risk for autism: gaze following and attentional engagement

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    Whilst joint attention (JA) impairments in autism have been widely studied, little is known about the early development of gaze following, a precursor to establishing JA. We employed eye-tracking to record gaze following longitudinally in infants with and without a family history of autism spectrum disorder (ASD) at 7 and 13 months. No group difference was found between at-risk and low-risk infants in gaze following behaviour at either age. However, despite following gaze successfully at 13 months, at-risk infants with later emerging socio-communication difficulties (both those with ASD and atypical development at 36 months of age) allocated less attention to the congruent object compared to typically developing at-risk siblings and low-risk controls. The findings suggest that the subtle emergence of difficulties in JA in infancy may be related to ASD and other atypical outcomes

    What you see is what you get: contextual modulation of face scanning in typical and atypical development

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    Infants’ visual scanning of social scenes is influenced by both exogenously and endogenously driven shifts of attention. We manipulate these factors by contrasting individual infants’ distribution of visual attention to the eyes relative to the mouth when viewing complex dynamic scenes with multiple communicative signals (e.g. peek-a-boo), relative to the same infant viewing simpler scenes where only single features move (moving eyes, mouth and hands). We explore the relationship between context-dependent scanning patterns and later social and communication outcomes in two groups of infants, with and without familial risk for autism. Our findings suggest that in complex scenes requiring more endogenous control of attention, increased scanning of the mouth region relative to the eyes at 7 months is associated with superior expressive language (EL) at 36 months. This relationship holds even after controlling for outcome group. In contrast, in simple scenes where only the mouth is moving, those infants, irrespective of their group membership, who direct their attention to the repetitive moving feature, i.e. the mouth, have poorer EL at 36 months. Taken together, our findings suggest that scanning of complex social scenes does not begin as strikingly different in those infants later diagnosed with autism
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