Exploring development of infant gaze, affect, and object exploration in a primarily Latino sample

Infants demonstrate rapid development across the first years of life, which underlies increased human interactions that promote social-emotional development. In particular, gaze, affect, and object exploration are early indicators of engagement and show rapid changes in the first year of life. However, current understanding on developmental trajectories during infancy often comes from majority white, non-Hispanic/Latino samples. This longitudinal study explored the development of infant gaze, affect, and object exploration across 2-18 months of age in a sample of primarily Latino infants drawn from a pediatric community clinic. Videos of mother-infant play when infants were 2, 6, 9, 12 and 18 months were coded for durations of three types of behaviors: gaze, affect, and object exploration. Additionally, mother-infant play videos when the infant was 24 months of age were coded for joint engagement. Descriptive statistics for the three behavior types were obtained at each timepoint, and repeated measures analysis of covariance investigated the development of behaviors from timepoint to timepoint. Latent growth curve analyses were conducted to analyze developmental trajectories of capacities across 2-18 months, as well as development in relation to joint engagement at 24 months. Results indicate an important development period from 2 to 6 months of infants' life, unique developmental patterns of specific behaviors, and heterogeneity in gaze development in the sample and across ages. Overall, this study provides an important description of development within mother-infant play in a primarily Latino sample.

The process of learning the designed actions of toys

Many everyday objects require "hidden" affordances to use as designed (e.g., twist open a water bottle). Previous work found a reliable developmental progression in children's learning of designed actions with adult objects such as containers and zippers-from non-designed exploratory actions, to the basics of the designed action, to successful implementation. Many objects designed for children (e.g., toys) also entail designed actions (e.g., interlocking bricks) but might not require a protracted period of discovery and implementation. We encouraged 12- to 60-month-old children (n = 91) and a comparative sample of 20 adults to play with six Duplo bricks to test whether the developmental progression identified for children's learning of adult objects with hidden affordances holds for a popular toy expressly designed for children. We also examined whether children's moment-to-moment behaviors with Duplo bricks inform on general processes involved in discovery and implementation of hidden affordances. With age, children progressed from non-designed exploratory actions, to attempts to interlock, to success, suggesting that the three-step developmental progression revealed with everyday adult objects broadly applies to learning hidden affordances regardless of object type. Detailing the process of learning (the type and timing of children's non-designed actions and attempts to interlock) revealed that the degree of lag between steps of the progression depends on the transparency of the required actions, the availability of perceptual feedback, and the difficulty of the perceptual-motor requirements. Findings provide insights into factors that help or hinder learning of hidden affordances.

A model for using developmental science to create effective early intervention programs and technologies to improve children's developmental outcomes

Children born with a variety of environmental or medical risk factors may exhibit delays in global development. Very often, such delays are identified at preschool or school age, when children are severely overdue for effective early interventions that can alleviate the delays. This chapter proposes a conceptual model of child development to inform the creation of interventions and rehabilitative technologies that can be provided very early in development, throughout the first year of life, to optimize children's future developmental outcomes. The model suggests that early sensorimotor skills are antecedent and foundational for future motor, cognitive, language, and social development. As an example, this chapter describes how children's early postural control and exploratory movements facilitate the development of future object exploration behaviors that provide enhanced opportunities for learning and advance children's motor, cognitive, language, and social development. An understanding of the developmental pathways in the model can enable the design of effective intervention programs and rehabilitative technologies that target sensorimotor skills in the first year of life with the goal of minimizing or ameliorating the delays that are typically identified at preschool or school age. Specific examples of early interventions and rehabilitative technologies that have effectively advanced children's motor and cognitive development by targeting early sensorimotor skills and behaviors are provided.

Comparative Behavioral Correlation of High and Low-Performing Mice in the Forced Swim Test

Behavioral analysis in mice provided important contributions in helping understand and treat numerous neurobehavioral and neuropsychiatric disorders. The behavioral performance of animals and humans is widely different among individuals but the neurobehavioral mechanism of the innate difference is seldom investigated. Many neurologic conditions share comorbid symptoms that may have common pathophysiology and therapeutic strategy. The forced swim test (FST) has been commonly used to evaluate the “antidepressant” properties of drugs yet the individual difference analysis of this test was left scantly investigated along with the possible connection among other behavioral domains. This study conducted an FST-screening in outbred CD-1 male mice and segregated them into three groups: high performers (HP) or the active swimmers, middle performers (MP), and low performers (LP) or floaters. After which, a series of behavioral experiments were performed to measure their behavioral responses in the open field, elevated plus maze, Y maze, three-chamber social assay, novel object recognition, delay discounting task, and cliff avoidance reaction. The behavioral tests battery revealed that the three groups displayed seemingly correlated differences in locomotor activity and novel object recognition but not in other behaviors. This study suggests that the HP group in FST has higher locomotor activity and novelty-seeking tendencies compared to the other groups. These results may have important implications in creating behavior database in animal models that could be used for predicting interconnections of various behavioral domains, which eventually helps to understand the neurobiological mechanism controlling the behaviors in individual subjects.

Involvement of the retrosplenial cortex in the processing of the temporal aspect of episodic-like memory in rats

To investigate the effects of retrosplenial cortex (RSC) lesions on episodic-like memory, we used four types of object recognition tasks. What task examined memory of object identities. Where task examined memory of object locations. When task examined memory of the temporal order of presented objects. Episodic task examined the integrated memory of the identity, location, and temporal order of presented objects. Rats with the RSC lesions preferred novel objects in the What and Where tasks, whereas they showed no such preference in the When and Episodic tasks, suggesting that rats with the RSC lesions have deficits in memory for temporal order and that this might cause deficits in episodic-like memory.

Play for Success: An intervention to boost object exploration in infants from low-income households

Infants from low-income households typically spend less time exploring objects and use less mature strategies when they do explore compared to their higher-income peers (e.g., Clearfield et al., 2014). The current study tested a novel intervention designed to boost early object exploration in infants from low-income households. The intervention, called Play for Success, was administered through the Early Head Start home visiting program, and asked all infants to explore a toy with a caregiver for 10 min a day every day for two weeks. Forty-two 6- to 10-month-old infants were randomly assigned to one of three intervention groups: Social (unstructured direction), Teach Two (simple structured direction), or Teach Many (complex structured direction). Infants' exploratory behaviors were tested three times: before the intervention, immediately following, and again four weeks later. The results demonstrated that only infants in Teach 2 maintained their level of exploration at both the post-test and 4 weeks later while infants in the other groups showed significant decreases in exploration over time. These results suggest that Play for Success is a promising new intervention, but only in the condition that included repeated simple structured direction.

Does early object exploration support gesture and language development in extremely preterm infants and full-term infants?

BACKGROUND

An increasing body of research on typically and atypically developing infants has shown that motor skills play an important role in language development. To date, however, the role of specific object exploration skills for early gesture and vocabulary development has not been investigated in extremely low gestational age infants (ELGA, GA < 28 weeks), who are at greater risk for motor and language delays than full-term (FT) infants.

PURPOSE

This longitudinal study examined relations between 6-month active exploratory behaviors and 12- month word comprehension, gestures and vocal production, controlling for cognitive performance and neonatal condition (ELGA vs FT).

METHODS

Forty infants, 20 ELGA and 20 FT, and their mothers participated in the study. Mother-infant play interaction was video-recorded at 6 and 12 months. Oral and manual object exploration at 6 months and spontaneous gestures and vocal production at 12 months were coded. Word comprehension was evaluated with the Italian version of the MacArthur-Bates CDI parent questionnaire at 12 months. Cognitive performance was examined with the Griffiths Mental Developmental Scales at 6 months and the Bayley-III Scales at 12 months.

RESULTS

Regression analyses showed that after accounting for cognitive performance and neonatal condition, oral exploration was related to word comprehension, and manual exploration to gestures and vocal production in the overall sample.

CONCLUSIONS

Cascading effects of specific object exploration skills on gestures and language comprehension and production in preterm infants and FT infants are discussed. Clinical implications for early assessment of and interventions involving object exploration skills, which may affect language development, are considered for the preterm population.

Object exploration in extremely preterm infants between 6 and 9 months and relation to cognitive and language development at 24 months

Although early object exploration is considered a key ability for subsequent achievements, very few studies have analyzed its development in extremely low gestational age infants (ELGA- GA <28 weeks), whose early motor skills are delayed. Moreover, no studies have examined its developmental relationship with cognitive and language skills. The present study examined developmental change in Motor Object Exploration (MOE) and different types of MOE (Holding, Oral, Manual and Manual Rhythmic Exploration) in 20 ELGA and 20 full term (FT) infants observed during mother-infant play interaction at 6 and 9 months. It also explored whether specific types of MOE were longitudinally related to 24-month language and cognitive abilities (GMDS-R scores). ELGA infants increased MOE duration from 6 to 9 months, eliminating the initial difference with FT infants. In addition, ELGA infants showed a different pattern of Oral Exploration, that did not increase at 6 months and decrease at 9 months. Oral and Manual Exploration durations at 6 months were longitudinally related to 24-month GMDS-R language and cognitive performance scores respectively. We discuss the relevance of assessing early exploratory abilities in ELGA infants in order to implement customized intervention programs for supporting the development of these skills.

Characteristics of brief sticky mittens training that lead to increases in object exploration

The onset of independent prehension marks the beginning of infants' direct interaction with the physical world. The success infants have in contacting objects with their hands and arms can have both visual and auditory consequences; objects may move and collide with other objects or fall onto table surfaces. Seeing and hearing these events could have important consequences for infants' learning about objects and their subsequent behavior toward objects. The current research assessed the effects of brief object manipulation experiences and how a specific characteristic of training, auditory feedback produced by hard plastic toys colliding with a tabletop surface, affects pre-reaching infants' subsequent object exploration. In Experiment 1, infants participated in either active "sticky" mittens training or passive "nonsticky" mittens training with a set of toys; before and after this experience, infants explored a teether. Results showed that infants participating in active training increased looking toward and sustained touching of the teether from pre- to post-training, whereas infants receiving passive training decreased their looking toward and touching of the teether following training. To investigate whether infants' exploration behaviors were related to the amount of auditory feedback produced by the objects during training, in Experiment 2 data were collected from infants who received active sticky mittens training that had either more or less auditory feedback potential. Results showed more robust increases in infants' exploratory activity from pre- to post-training in the more auditory feedback condition compared with infants' exploratory activity in the less auditory feedback condition. These findings support the idea that active control of objects, including experiencing contingent feedback through multiple sensory modalities, promotes the development of object exploration during early infancy.

A novel tool-use mode in animals: New Caledonian crows insert tools to transport objects

New Caledonian crows (Corvus moneduloides) rely heavily on a range of tools to extract prey. They manufacture novel tools, save tools for later use, and have morphological features that facilitate tool use. We report six observations, in two individuals, of a novel tool-use mode not previously reported in non-human animals. Insert-and-transport tool use involves inserting a stick into an object and then moving away, thereby transporting both object and tool. All transported objects were non-food objects. One subject used a stick to transport an object that was too large to be handled by beak, which suggests the tool facilitated object control. The function in the other cases is unclear but seems to be an expression of play or exploration. Further studies should investigate whether it is adaptive in the wild and to what extent crows can flexibly apply the behaviour in experimental settings when purposive transportation of objects is advantageous.

Concurrent assessment of memory for object and place: Evidence for different preferential importance of perirhinal cortex and hippocampus and for promnestic effect of a neurokinin-3 R agonist

We here explore the utility of a paradigm that allows the simultaneous assessment of memory for object (what) and object location (where) and their comparative predominance. Two identical objects are presented during a familiarity trial; during the test trial one of these is displaced, and a new object is presented in a familiar location. When tested 5 or 80min later, rats explored both the novel and the displaced objects more than two familiar stationary objects, indicating intact memory for both, object and place. When tested 24h later rats explored the novel object more than the displaced familiar one, suggesting that forgetting differently influenced object and place memory, with memory for object being more robust than memory for place. Animals that received post-trial administration of the neurokinin-3 receptor agonist senktide and were tested 24h later, now explored the novel and displaced objects equally, suggesting that the treatment prevented the selective decay of memory for location. Next, animals received NMDA lesions in either the perirhinal cortex or the hippocampus, which are hypothesized to be preferentially involved in memory for objects and memory for place, respectively. When tested 5 or 80min later, the perirhinal cortex lesion group explored the displaced object more, indicating relatively deficient object memory, while the hippocampal lesion led to the opposite pattern, demonstrating comparatively deficient place memory. These results suggest different preferential engagement of the perirhinal cortex and hippocampus in their processing of memory for object and place. This preference test lends itself to application in the comparison of selective lesions of neural sites and projection systems as well as to the assessment of possible preferential action of pharmacological agents on neurochemical processes that subserve object vs place learning.

Characterization and intervention for upper extremity exploration & reaching behaviors in infancy

This article aims to: 1) highlight general exploration, reaching, and object exploration behaviors as key activities of daily living in infancy, 2) describe how knowledge of early warning signs for these behaviors may improve early assessment, and 3) discuss interventions that may advance performance of these behaviors. Early intervention should focus on improving performance of these behaviors because: a) these early, interrelated upper extremity behaviors serve an integral role in global learning and development in infancy, b) among at-risk populations, differences have been observed in the quantity and quality of performance of these behaviors and, in many cases, these differences are associated with related perceptual-motor and cognitive delays. This article highlights how early assessment and intervention can target these key early behaviors in populations at risk for upper extremity disabilities, such as those born preterm, with Down syndrome, brachial plexus palsy, or arthrogryposis multiplex congentia.

Reduced social interaction, behavioural flexibility and BDNF signalling in the BTBR T+ tf/J strain, a mouse model of autism

Autism is a neurodevelopmental disorder characterized by social and communication impairments and repetitive behaviours. The inbred BTBR T+ tf/J (BTBR) strain, a putative mouse model of autism, exhibits lower social interactions, higher repetitive self-grooming levels and unusual pattern of vocalizations as compared to C57BL/6J strain. First aim of the present study was to evaluate at adolescence (postnatal days 30-35) male BTBR and C57BL/6J performances in two different tasks involving either investigation of social cues (same strain partners) or non social ones (inanimate objects). In the social interaction test, BTBR mice showed a reduction of investigation of the social partner, due to a selective reduction of head sniffing, associated with a decrease in ultrasonic vocalizations. By contrast, no strain differences were detected in object investigations. Second aim of the study was to evaluate adult male BTBR and C57BL/6J performances in a fear conditioning task. Strain differences were evident during contextual retest: these strain differences primarily suggested a lack of behavioural flexibility in BTBR mice (i.e., realizing the occurrence of changes in the experimental paradigm). Subsequent electrophysiological analysis in hippocampal slices from adult BTBR and C57BL/6J mice revealed a significant reduction of Brain Derived Neurotrophic Factor (BDNF)-induced potentiation of synaptic transmission in BTBR mice. BDNF and tyrosine kinase B (TrkB) protein levels measured in the hippocampal region were also lower in BTBR as compared to C57BL/6J mice. These data confirm the presence of low levels of direct interaction with social stimuli in BTBR mice at adolescence, in the absence of any strain difference as for investigation of physical objects. At adulthood in BTBR mice clear signs of behavioural inflexibility were evident whereas both biochemical and electrophysiological data point to decreased BDNF signalling (likely due to a reduction in TrkB levels) in the hippocampus of this mouse strain.