Comparing apples to manzanas and oranges to naranjas: A new measure of English-Spanish vocabulary for dual language learners.

The valid assessment of vocabulary development in dual-language-learning infants is critical to developmental science. We developed the Dual Language Learners English-Spanish (DLL-ES) Inventories to measure vocabularies of U.S. English-Spanish DLLs. The inventories provide translation equivalents for all Spanish and English items on Communicative Development Inventory (CDI) short forms; extended inventories based on CDI long forms; and Spanish language-variety options. Item-Response Theory analyses applied to Wordbank and Web-CDI data (n = 2603, 12-18 months; n = 6722, 16-36 months; half female; 1% Asian, 3% Black, 2% Hispanic, 30% White, 64% unknown) showed near-perfect associations between DLL-ES and CDI long-form scores. Interviews with 10 Hispanic mothers of 18- to 24-month-olds (2 White, 1 Black, 7 multi-racial; 6 female) provide a proof of concept for the value of the DLL-ES for assessing the vocabularies of DLLs.

Movement as a Gateway to Participation for Individuals With Neuromotor Conditions: A Scoping Review.

PURPOSE: The purpose of this scoping review was to examine and analyze the developmental and rehabilitation literature related to movement and participation at key points of transition for individuals with neuromotor conditions. METHODS: Arksey and O'Malley's scoping review protocol was applied, and 37 articles were included. Extracted data included population, developmental transition points, movement opportunity, type of participation, and outcome measures. RESULTS: Most studies covered developmental transition points; none examined transitions as a variable for participation outcomes. Physical activity/exercise was the most common movement opportunity. Most publications used formal outcome measures of participation; others used observation or interviews. CONCLUSION: No publications adequately addressed the effect of movement opportunities on participation during developmental transition points.

Dynamics of the dyad: How mothers and infants co-construct interaction spaces during object play.

Studies of dyadic interaction often examine infants' social exchanges with their caregivers in settings that constrain their physical properties (e.g., infant posture, fixed seating location for infants and adults). Methodological decisions about the physical arrangements of interaction, however, may limit our ability to understand how posture and position shape them. Here we focused on these embodied properties of dyadic interaction in the context of object play. We followed 30 mother-infant dyads across the first year of life (at 3, 6, 9, and 12 months) and observed them during 5 min of play with a standard set of toys. Using an interval-based coding system, we measured developmental change in infant posture, how mothers and infants positioned themselves relative to one another, and how they populated interaction spaces with objects. Results showed that mother-infant dyads co-constructed interaction spaces and that the contributions of each partner changed across development. Dyads progressively adopted a broader spatial co-orientation during play (e.g., positioned at right angles) across the first year. Moreover, advances in infants' postural skills, particularly increases in the use of independent sitting in real time, uniquely predicted change in dyadic co-orientation and infants' actions with objects, independent of age. Taken together, we show that the embodied properties of dyadic object play help determine how interactions are physically organized and unfold, both in real time and across the first year of life.

Equifinality in infancy: The many paths to walking.

Many different pathways can lead to the same result or developmental outcome. What are the developmental routes that result in the onset of walking? In this longitudinal study, we documented patterns of infant locomotion during everyday activities at home for 30 prewalking infants. Using a milestone-based design, we focused on observations spanning the two months before the onset of walking (M age at walk onset = 11.98 months, SD = 1.27). We examined how much time infants spent in motion and when they moved, whether they were more likely to do so while prone (crawling) or upright with support (cruising or supported walking). Results showed immense variability in infants' practice regimes en route to walking-some infants spent relatively similar amounts of time crawling, cruising, and supported walking at each session, others preferred one method of travel over the alternatives, and some switched between different types of locomotion from session to session. In general, however, infants spent a larger share of their movement time in upright positions compared to prone. Finally, our densely sampled dataset revealed a clear feature of locomotor development: infants follow many distinct and variable paths to walk onset, regardless of the age at which it is attained.

Caregiver object labels within supported and coordinated joint engagement during interaction with toddlers at elevated and typical likelihood of autism.

BACKGROUND: Early in development, caregivers' object labelling contributes to children's word learning. Language development is a bi-directional process, and differences in joint engagement (JE) and language among children with developmental disabilities such as autism spectrum disorder (ASD) may provide caregivers varying contexts and opportunities to provide object labels. However, potential variation in caregivers' production of object labels and its relation to language development remain relatively unexplored among toddlers with ASD. AIMS: This study characterized the structural and functional features of object labels produced by parents of children with typical (TL) or elevated likelihood (EL) of ASD during naturalistic toy play. We examined features of object labels within two JE contexts, supported and coordinated JE, which are differentiated by a child's use of eye contact, as well as their relations with concurrent and future child language skills. METHODS & PROCEDURES: The present study included 55 (TL = 12, EL = 43) children who completed a naturalistic parent-child interaction in the home at 18 months of age. Children's expressive and receptive language was assessed at 18, 24 and 36 months. At 36 months, EL children were assessed for ASD and classified as either EL-No Diagnosis, EL-Language Delay or EL-ASD. Videos of interactions were divided into discrete engagement states, including supported and coordinated JE. All parent speech was transcribed and coded to capture structural (types, tokens, mean length of utterance (MLU), sentence position) and functional (follow-in comments, directives, lead-in labels) features of object labels as well as parent prompts for the child to produce a label. OUTCOMES & RESULTS: Parents of toddlers across outcome groups labelled objects at similar rates within each engagement state. However, parents of EL-ASD children provided the lowest rates of prompts for labels in supported JE and the highest rate of labels as the final word of an utterance (sentence-final position) in coordinated JE. Additionally, parent prompts in supported JE were related to concurrent child expressive language. Labels in sentence-final position were positively related to later language outcome when delivered in supported JE but were associated with poorer language outcomes when delivered in coordinated JE. CONCLUSIONS & IMPLICATIONS: Subtle differences in parent object labels across outcome groups demonstrate the role that child language and social engagement can play in influencing parent input and the cascading impact of this input on language development. WHAT THIS PAPER ADDS: What is already known on this subject Variations in caregiver object labelling can impact child language development. However, child characteristics such as language ability also actively shape the input caregivers provide, demonstrating the bi-directionality of language development. What this paper adds to existing knowledge The present study demonstrates that characteristics of the engagement context in which a label is delivered may be important for understanding how object labelling relates to child language acquisition and whether this relation varies for children who face challenges in language learning. What are the potential or actual clinical implications of this work? As child differences in social engagement emerge, parents may be more attuned to moments their children are engaging with eye contact. Caregiver-mediated interventions might consider strategies that guide caregivers in recognizing engagement without eye contact as a similarly meaningful opportunity for learning and encourage the use of rich input within these moments.

Infant locomotion shapes proximity to adults during everyday play in the U.S.

Learning to walk expands infants' access to the physical environment and prompts changes in their communicative behaviors. However, little is known about whether walking also shapes infants' proximity to their adult social partners during everyday activities at home. Here we followed 89 infants (42 boys, 47 girls; 92% White, not Hispanic or Latino) longitudinally and documented connections between infant locomotion and infant-adult proximity on two timescales: (1) across developmental time, by comparing data from a session when infants could only crawl to a later session when they could walk (M walk onset = 12.15 months, range = 8-15); and (2) in real time, by testing whether the amount of time that infants spent in motion (regardless of their locomotor status) related to their interpersonal distance to adults. The developmental transition to walking corresponded to a significant, but modest, decrease in infant-adult proximity. Infants' moment-to-moment locomotion, however, was strongly related to patterns of interpersonal distance: infants who spent more time in motion spent less time near adults and instigated more proximity transitions, resulting in shorter and more dispersed bouts of proximity throughout sessions. Findings shed new light on how infants' motor achievements can reverberate across other domains of development, and how changes in infant development that researchers often observe over months arise from infants' moment-to-moment experiences.

Posture Matters: Object Manipulation During the Transition to Arms-Free Sitting in Infants at Elevated vs. Typical Likelihood for Autism Spectrum Disorder.

Aims: We investigated how infants grasped and transferred toys over a four-week period as they transitioned to arms-free sitting. We compared object manipulation in infants with typical likelihood (TL) and elevated likelihood (EL) for autism spectrum disorder (ASD) as they sat with vs. without support.Methods: Eighteen infants (7 EL; 11 TL; 5-8 months of age at the start of the study) were observed during three sessions at home across the transition to arms-free sitting. At each session, toys were presented to the infants in two different postures: sitting with support from a boppy pillow and sitting independently. Mean percentage of time spent grasping and rates of transferring objects between two hands were calculated for each infant at each session.Results: Both grasping time and transfer rate increased across the transition to arms-free sitting. EL infants, but not TL infants, spent significantly less time grasping toys when sitting independently than when sitting with support.Conclusions: Sitting plays a significant role in the development of object manipulation skills. Our results reveal a need to examine object manipulation skills in multiple posture contexts, especially in infants who exhibit motor delays.

Attention and sensory integration for postural control in young adults with autism spectrum disorders.

Postural control impairments have been reported in adults with autism spectrum disorders (ASD). Balance relies on the integration of multisensory cues, a process that requires attention. The purpose of this study was to determine if the influence of attention demands on sensory integration abilities relevant for balance partially contributes to postural control impairments in ASD. Young adults with ASD (N = 24) and neurotypical participants (N = 24) were exposed to sensory perturbations during standing. An established dual-task paradigm was used, requiring participants to maintain balance in these sensory challenging environments and to perform auditory information processing tasks (simple reaction time task and choice reaction time task). Balance was assessed using sway magnitude and sway speed, and attention demands were evaluated based on the response time in the auditory tasks. While young adults with ASD were able to maintain balance in destabilizing sensory conditions, they were more challenged (greater sway speed) than their neurotypical counterparts. Additionally, when exposed for an extended amount of time (3 min) to the most challenging sensory condition included in this study, adults with ASD exhibited a reduced ability to adapt their postural control strategies (sway speed was minimally reduced), demonstrating a postural inflexibility pattern in ASD compared to neurotypical counterparts. Finally, the impact of performing an auditory information processing task on balance and the dual-task cost on information processing (response time) was similar in both groups. ASD may disrupt temporal adaptive postural control processes associated with sensory reweighting that occurs in neurotypicals.

Communication changes when infants begin to walk.

Learning to walk allows infants to travel faster and farther and explore more of their environments. In turn, walking may have a cascading effect on infants' communication and subsequent responses from caregivers. We tested for an inflection point-a dramatic shift in the developmental progression-in infant communication and caregiver responses when infants started walking. We followed 25 infants longitudinally over 7 months surrounding the onset of walking (mean walk onset age = 11.76 months, SD = 1.56). After learning to walk, the pace of gesture growth (but not vocalization growth) increased substantially, and infants increasingly coordinated gestures and vocalizations with locomotion (e.g., by walking to a caregiver and showing off a toy bear). Consequently, caregivers had more opportunities to respond contingently to their infants during walking months compared to crawling months (e.g., "What did you find? Is that your bear?"). Changes in communication were amplified for infants who began walking at older ages, compared to younger walkers. Findings suggest that learning to walk marks a point in development when infants actively communicate in new ways, and consequently elicit rich verbal input from caregivers.

Multimodal coordination of vocal and gaze behavior in mother-infant dyads across the first year of life.

Research examining mother-infant interactions indicates a close connection between vocal and gaze behavior. The present longitudinal study examined the development of both intraindividual and dyadic coordination of vocal and gaze behavior in mother-infant dyads at 3, 6, 9, and 12 months. Mother and infant vocalization and gaze behavior during in-home toy play interactions were coded on a moment-by-moment basis and coordinations (i.e., co-occurrences and sequences of behavior) were compared to randomized baselines in order to determine whether coordinate exceeded chance levels. Infants timed their own vocalizations with gaze to partner's face and inhibited vocalizations during gaze to objects at greater than chance levels across the first year. Mother's displayed above-chance intraindividual coordination of vocalizations and gaze to partner's face and objects. Mothers and infants demonstrated dyadic coordination of vocalizations and gaze at above-chance levels, but developmental change and leading-following dynamics varied based on gaze location (i.e., face vs. object). Results emphasize the importance of examining coordination across communication modalities and of considering bidirectional influences on mother and infant vocal and gaze behavior.

Object exploration during the transition to sitting: A study of infants at heightened risk for autism spectrum disorder.

Learning to sit promotes infants' object exploration because it offers increased access to objects and an improved position for exploration (e.g., ). Infants at heightened risk (HR) for autism spectrum disorder (ASD) exhibit delays in sitting and differences in object exploration. However, little is known about the association between sitting and object exploration among HR infants. We examined changes in object exploration as HR infants (N = 19) and comparison infants with no family history of ASD (Low Risk; LR; N = 23) gained experience sitting independently. Infants were observed monthly from 2.5 months until 1 month after the onset of independent sitting. At 12, 18, 24, and 36 months, infants completed standardized developmental assessments, and HR infants were assessed for ASD symptoms at 36 months. Although HR infants began sitting later than LR infants, both groups increased time spent grasping, shaking, banging, and mouthing objects as they gained sitting experience. Groups only differed in time spent actively mouthing objects, with LR infants showing a greater increase in active mouthing than HR infants. Findings suggest that HR infants experience a similar progression of object exploration across sitting development, but on a delayed time scale.

Word comprehension mediates the link between gesture and word production: Examining language development in infant siblings of children with autism spectrum disorder.

Children's gesture production precedes and predicts language development, but the pathways linking these domains are unclear. It is possible that gesture production assists in children's developing word comprehension, which in turn supports expressive vocabulary acquisition. The present study examines this mediation pathway in a population with variability in early communicative abilities-the younger siblings of children with autism spectrum disorder (ASD; high-risk infants, HR). Participants included 92 HR infants and 28 infants at low risk (LR) for ASD. A primary caregiver completed the MacArthur-Bates Communicative Development Inventory (Fenson, et al., 1993) at 12, 14, and 18 months, and HR infants received a diagnostic evaluation for ASD at 36 months. Word comprehension at 14 months mediated the relationship between 12-month gesture and 18-month word production in LR and HR infants (ab = 0.263; p < 0.01). For LR infants and HR infants with no diagnosis or language delay, gesture was strongly associated with word comprehension (as = 0.666; 0.646; 0.561; ps < 0.01). However, this relationship did not hold for infants later diagnosed with ASD (a = 0.073; p = 0.840). This finding adds to a growing literature suggesting that children with ASD learn language differently. Furthermore, this study provides an initial step toward testing the developmental pathways by which infants transition from early actions and gestures to expressive language.

The Relation Between Walking and Language in Infant Siblings of Children With Autism Spectrum Disorder.

In typical development, walk onset is accompanied by increased language growth (e.g., Walle & Campos, 2014). The present study explored whether this relation may be disrupted in the infant siblings of children with autism spectrum disorder (ASD; heightened risk of receiving an ASD diagnosis; HR), a population exhibiting substantial variability in motor and language development (e.g., Gamliel, Yirmiya, & Sigman, 2007; Landa & Garrett-Mayer, 2006). Receptive and expressive language were examined across the transition to walking in three groups of HR infants (no diagnosis, language delay, and ASD; N = 91, 8-18 months) and in infants with no family history of ASD (N = 25; 9-15 months). Only infants with an eventual ASD diagnosis did not show increased language growth following walk onset.

Coordination is key: Joint attention and vocalisation in infant siblings of children with Autism Spectrum Disorder.

BACKGROUND: Research indicates that social communicative behaviours develop atypically during the second year in Autism Spectrum Disorder (ASD). This study evaluated whether these behaviours also differed in the extent to which they were coordinated across modalities. AIMS: To measure joint attention behaviours (e.g., gaze shifts, gestures), vocalisations and their coordination among a cohort of infants with an older sibling with ASD (heightened risk-HR). METHODS & PROCEDURES: This prospective longitudinal study examined 50 HR infants at 14, 18 and 24 months. The Early Social Communication Scales (ESCS)-a structured toy-play task that assesses infant joint attention behaviour-was administered to infants at each age point in the home. Infants' joint attention behaviours, vocalisations and instances where they overlapped were coded from videos. At 36 months, nine infants received an ASD diagnosis (HR-ASD), 15 had a significant language delay (HR-LD) and 26 were classified no diagnosis (HR-ND). OUTCOMES & RESULTS: Findings revealed that HR-ASD infants produced fewer advanced joint attention behaviours, and their vocalisations were less frequent and less advanced than HR-LD and HR-ND infants. Notably, HR-ASD infants also coordinated these behaviours together less frequently than their HR peers. CONCLUSIONS & IMPLICATIONS: Differences in the coordination of early communicative behaviours may have negative cascading effects on social and language development for infants who develop ASD. Current intervention practices may be complemented by efforts to increase the coordinated quality of communicative behaviours.

Gesture development in toddlers with an older sibling with autism.

BACKGROUND: Nonverbal communication deficits are characteristic of autism spectrum disorder (ASD) and have been reported in some later-born siblings of children with ASD (heightened-risk (HR) children). However, little work has investigated gesture as a function of language ability, which varies greatly in this population. AIMS: This longitudinal study characterizes gesture in HR children and examines differences related to diagnostic outcome (ASD, language delay, no diagnosis) and age. METHODS & PROCEDURES: We coded communicative gesture use for 29 HR children at ages 2 and 3 years during interactions with a caregiver at home. OUTCOMES & RESULTS: Children in the ASD group produced fewer gestures than their HR peers at 2 years, though large individual differences were observed within each subgroup at both ages. In addition, reliance on particular types of gestures varied with age and outcome. Both ASD and language delay children exhibited a pattern of reduced pointing relative to their no diagnosis peers. CONCLUSIONS & IMPLICATIONS: Similarities and differences exist between communication in HR infants with language delay and their HR peers, reinforcing our understanding of links between verbal and nonverbal communication in populations at risk for language delay.

Adding to the Conversation: Language Delays and Parent-Child Interactions in the Younger Siblings of Children With Autism.

In their first three years, children begin to maintain topics and add new information in conversation. In turn, caregivers create opportunities for language learning. Compared to children with no family history of autism (typical likelihood, TL), the younger siblings of children with autism spectrum disorder (ASD) are at elevated likelihood (EL) for both ASD and language delays. This study asked: (1) Do profiles of spoken language and conversational skills differ across groups? (2) Does spoken language relate to conversational skills? and (3) How does parent speech relate to child spoken language and conversational skills? Child spoken language, conversational skills, and parent speech were examined during toy play at home with three-year-old TL (n = 16) and EL children with ASD (EL-ASD, n = 10), non-ASD language delay (EL-LD, n = 21), and no delays or diagnoses (EL-ND, n = 37). EL-ASD children produced fewer intelligible utterances, and EL-LD and EL-ASD children produced shorter utterances than TL and EL-ND children. When utterances were intelligible, all groups were highly contingent to the topic. EL-ASD children were less likely than all other groups to add new information, and adding new information was positively associated with utterance length. Parents of EL-ASD children had fewer opportunities to respond contingently. However, all parents were highly topic-contingent when child speech was intelligible, and parent speech complexity varied with child language and conversational skills. Findings highlight strengths in conversational skills for EL-ASD children during toy play with parents and show that children and caregivers together shape opportunities for developing language and conversation.

Breakdowns and repairs: Communication initiation and effectiveness in infants with and without an older sibling with autism.

Infants initiate interactions to get their wants and needs met; but sometimes they are not effective in their communication and are misunderstood by caregivers. When this happens, they must recognize this breakdown in communication and attempt repairs. Experimental literature suggests that in neurotypically developing infants these skills develop during the first two years. However, little work has investigated communication breakdowns and repairs in populations of infants with known social communication difficulties (e.g., infants with an elevated likelihood for autism). Here we explored early social communication initiations, breakdowns, and repair strategies in naturalistic videos of 18-month-old infants (N = 64) with elevated likelihood (EL) for autism and other developmental delays (N = 49) and infants with population-level likelihood for autism (e.g., typical likelihood, TL, N = 15). EL infants, including those who later met criteria for autism (EL-AUT), initiated with caregivers, experienced breakdowns, and made repairs at similar rates to TL infants. However, the types of behaviors used differed, such that EL infants appeared to have a relative strength in making behavior regulation bids. EL-AUT infants used a large proportion of developmentally appropriate repair behaviors (i.e., addition and substitution), even though their repertoires of repair strategies were smaller. Additionally, EL-AUT infants produced a larger proportion of simplification repairs, which are less developmentally advanced and less helpful to interlocutors. Identifying patterns in how EL infants communicate with caregivers and capitalizing on their strengths could improve interventions focused on social communication.

Expression and co-regulation of negative emotion in 18-month-olds at increased likelihood for autism with diverse developmental outcomes.

LAY ABSTRACT: Managing negative emotion can be challenging for autistic individuals and their families from a young age. Parents help young children manage negative emotions by responding in comforting or supportive ways. Not much research has examined how negative emotions and parent responses to negative emotions are different in very young autistic children. This study used videotapes of 18-month-old toddlers and parents at home. We examined how much and how intensely toddlers expressed negative emotion in everyday situations, and how parents responded. Participants were younger siblings of autistic children, and we compared three groups-children that (1) later received an autism diagnosis; (2) had language delays but not autism; and (3) had no delays or autism. We found that autistic toddlers' negative emotion was more likely to be intense and to continue once it started compared with children without delays or autism. Language-delayed toddlers also showed some, but not all these differences. Parents responded similarly to negative emotions in all groups. When parents used strategies to help, it reduced the chances of the negative emotions continuing, although it may have been less helpful for autistic toddlers. This study shows that autistic children may express more intense and long-lasting negative emotions from an early age. It also shows that parents of autistic children are very responsive to their children's negative emotions, but these responses may not be as helpful to autistic children. While more research is needed, this study helps us understand how autistic toddlers may express and experience emotions differently.

Attention and sensory integration for gait in young adults with autism spectrum disorder.

INTRODUCTION: Altered sensorimotor function is a common feature of autism spectrum disorder (ASD). As a result, spatiotemporal walking patterns are typically affected. Attentional processes relevant for locomotion may be altered in people with ASD. This study assessed the extent to which gait alterations observed under sensory challenging conditions are due to reduced attention-related processes in young adults with ASD. METHODS: Twenty-one adults with ASD and 21 age- and sex-matched neurotypical participants walked at a self-selected pace on a 10-m walkway under 12 sensory/attention conditions: hard or carpet flooring; well-lit or dim lighting; no attention task, an auditory choice-reaction time information-processing task, or a simple reaction time information-processing task. Gait data were collected with a 12-marker motion capture set and a trunk accelerometer. Spatiotemporal characteristics of gait were derived and compared between the two groups across gait conditions. RESULTS: Floor/light conditions impacted gait speed, average step length, average stance time, average step width, and step width variability similarly in both groups (p<0.05). The information processing tasks impacted average step length, gait speed, and step length variability (p<0.05). Group differences were found in step length metrics: the ASD group had decreased average step length during the simple reaction time information-processing task and neurotypical participants did not (p=0.039); the ASD group had increased variability on carpet compared to hard floor and the neurotypical group had no change in variability due to floor (p=0.015). SIGNIFICANCE: These results suggest that attentional set-shifting and somatosensory inputs may play an important role in ASD-related gait alterations. Step length metrics appear to be sensitive to group differences between ASD and neurotypical adults during sensory challenging conditions.

Fine motor skill predicts expressive language in infant siblings of children with autism.

We investigated whether fine motor and expressive language skills are related in the later-born siblings of children with autism (heightened-risk, HR infants) who are at increased risk for language delays. We observed 34 HR infants longitudinally from 12 to 36 months. We used parent report and standardized observation measures to assess fine motor skill from 12 to 24 months in HR infants (Study 1) and its relation to later expressive vocabulary at 36 months in HR infants (Study 2). In Study 1, we also included 25 infants without a family history of autism to serve as a normative comparison group for a parent-report fine motor measure. We found that HR infants exhibited fine motor delays between 12 and 24 months and expressive vocabulary delays at 36 months. Further, fine motor skill significantly predicted expressive language at 36 months. Fine motor and expressive language skills are related early in development in HR infants, who, as a group, exhibit risk for delays in both. Our findings highlight the importance of considering fine motor skill in children at risk for language impairments and may have implications for early identification of expressive language difficulties.