Continuities and discontinuities in infants' representation of objects and events

A cultural perspective of action-based learning by infants and young children

Decades of research have informed about ways in which infants and young children learn through action in connection with their sensory system. However, this research has not strongly addressed the issues of cultural diversity or taken into account everyday cultural experiences of young learners across different communities. Diversifying the scholarship of early learning calls for paradigm shifts, extending beyond the analysis at the individual level to make close connections with real-world experience while placing culture front and center. On the other hand, cultural research that specifies diversity in caregiver guidance and scaffolding, while providing insights into young learners' cultural experiences, has been conducted separately from the research of action-based cross-modal learning. Taking everyday activities as contexts for learning, in this chapter, we summarize seminal work on cross-modal learning by infants and young children that connects action and perception, review empirical evidence of cultural variations in caregiver guidance for early action-based learning, and make recommendations of research approaches for advancing the scientific understanding about cultural ways of learning across diverse communities.

Development of the shape bias during the second year

The shape bias is an attentional preference children show for the shape of an object over other aspects of the object in a word-learning context. This bias, which aids in establishing a word-object pairing, was investigated in 12-, 18-, and 24-month-old children (n = 90) across noun, adjective, and no-label conditions. The present research presents evidence of development across this time span; there was a transition from a label reducing the chance of shape extensions to indiscriminate shape extensions to a label increasing the chance of shape extensions. This research supports the notion that children are focusing their extensions more toward shape during the course of development thereby developing a more mature and more specialized shape bias.

Human infancy…and the rest of the lifespan

Human infancy has been studied as a platform for hypothesis and theory testing, as a major physiological and psychological adjustment, as an object of adults' effects as well as a source of effects on adults, for its comparative value, as a stage of life, and as a setting point for the life course. Following an orientation to infancy studies, including previous reviews and a discussion of the special challenges infants pose to research, this article focuses on infancy as a foundation and catalyst of human development in the balance of the life course. Studies of stability and prediction from infancy illustrate the depth and complexity of modern research on infants and provide a long-awaited reply to key philosophical and practical questions about the meaningfulness and significance of infancy.

Infants use compression information to infer objects' weights: examining cognition, exploration, and prospective action in a preferential-reaching task

The present research used a preferential-reaching task to examine whether 9- and 11-month-olds (n=144) could infer the relative weights of two objects resting on a soft, compressible platform. Experiment 1 established that infants reached preferentially for the lighter of 2 boxes. In Experiments 2-4, infants saw 2 boxes identical except in weight resting on a cotton wool platform. Infants reached prospectively for the lighter box, but only when their initial exploratory activities provided critical information. At 11 months, infants succeeded as long as they first determined that the platform was compressible; at 9 months, infants succeeded only if they also explored the boxes and thus had advance knowledge that they differed in weight.

Rapid word learning in 13- and 17-month-olds in a naturalistic two-word procedure: looking versus reaching measures

This study investigated infants' rapid learning of two novel words using a preferential looking measure compared with a preferential reaching measure. In Experiment 1, 21 13-month-olds and 20 17-month-olds were given 12 novel label exposures (6 per trial) for each of two novel objects. Next, in the label comprehension tests, infants were shown both objects and were asked, "Where's the [label]?" (looking preference) and then told, "Put the [label] in the basket" (reaching preference). Only the 13-month-olds showed rapid word learning on the looking measure; neither age group showed rapid word learning on the reaching measure. In Experiment 2, the procedure was repeated 24h later with 10 participants per age group from Experiment 1. After a further 12 labels per object, both age groups now showed robust evidence of rapid word learning, but again only on the looking measure. This is the earliest looking-based evidence of rapid word learning in infants in a well-controlled (i.e., two-word) procedure; our failure to replicate previous reports of rapid word learning in 13-month-olds with a preferential reaching measure may be due to our use of more rigorous controls for object preferences. The superior performance of the younger infants on the looking measure in Experiment 1 was not straightforwardly predicted by existing theoretical accounts of word learning.

Occlusion is hard: Comparing predictive reaching for visible and hidden objects in infants and adults

Infants can anticipate the future location of a moving object and execute a predictive reach to intercept the object. When a moving object is temporarily hidden by darkness or occlusion, 6-month-old infants' reaching is perturbed but performance on darkness trials is significantly better than occlusion trials. How does this reaching behavior change over development? Experiment 1 tested predictive reaching of 6- and 9-month-old infants. While there was an increase in the overall number of reaches with increasing age, there were significantly fewer predictive reaches during the occlusion compared to visible trials and no age-related changes in this pattern. The decrease in performance found in Experiment 1 is likely to apply not only to the object representations formed by infants but also those formed by adults. In Experiment 2 we tested adults with a similar reaching task. Like infants, the adults were most accurate when the target was continuously visible and performance in darkness trials was significantly better than occlusion trials, providing evidence that there is something specific about occlusion that makes it more difficult than merely lack of visibility. Together, these findings suggest that infants' and adults' capacities to represent objects have similar signatures throughout development.

Occlusion is hard: Comparing predictive reaching for visible and hidden objects in infants and adults

Infants can anticipate the future location of a moving object and execute a predictive reach to intercept the object. When a moving object is temporarily hidden by darkness or occlusion, 6-month-old infants' reaching is perturbed but performance on darkness trials is significantly better than occlusion trials. How does this reaching behavior change over development? Experiment 1 tested predictive reaching of 6- and 9-month-old infants. While there was an increase in the overall number of reaches with increasing age, there were significantly fewer predictive reaches during the occlusion compared to visible trials and no age-related changes in this pattern. The decrease in performance found in Experiment 1 is likely to apply not only to the object representations formed by infants but also those formed by adults. In Experiment 2 we tested adults with a similar reaching task. Like infants, the adults were most accurate when the target was continuously visible and performance in darkness trials was significantly better than occlusion trials, providing evidence that there is something specific about occlusion that makes it more difficult than merely lack of visibility. Together, these findings suggest that infants' and adults' capacities to represent objects have similar signatures throughout development.

Aligning body and world: stable reference frames improve young children's search for hidden objects

This study investigated how young children's increasingly flexible use of spatial reference frames enables accurate search for hidden objects by using a task that 3-year-olds have been shown to perform with great accuracy and 2-year-olds have been shown to perform inaccurately. Children watched as an object was rolled down a ramp, behind a panel of doors, and stopped at a barrier visible above the doors. In two experiments, we gave 2- and 2.5-year-olds a strong reference frame by increasing the relative salience and stability of the barrier. In Experiment 1, 2.5-year-olds performed at above-chance levels with the more salient barrier. In Experiment 2, we highlighted the stability of the barrier (or ramp) by maximizing the spatial extent of each reference frame across the first four training trials. Children who were given a stable barrier (and moving ramp) during these initial trials performed at above-chance levels and significantly better than children who were given a stable ramp (and moving barrier). This work highlights that factors central to spatial cognition and motor planning-aligning egocentric and object-centered reference frames-play a role in the ramp task during this transitional phase in development.

Conflicting cues in a dynamic search task are reflected in children's eye movements and search errors

Three-year-olds were given a search task with conflicting cues about the target's location. A ball rolled behind a transparent screen and stopped behind one of four opaque doors mounted into the screen. A wall that protruded above one door provided a visible cue of blockage in the ball's path, while the transparent screen allowed visual tracking of the ball's progress to its last disappearance. On some trials these cues agreed and on others they conflicted. One group saw the ball appear to pass through the wall, violating its solidity, and another group saw the ball stop early, behind a door before the visual wall. Children's eye movements were recorded with an Applied Science Laboratories eye tracker during these real object events. On congruent trials, children tended to track the ball to the visible barrier and select that door. During conflict trials, children's eye movements and reaching errors reflected the type of conflict they experienced. Our data support Scholl and Leslie's (1999) hypotheses that spatio-temporal and contact mechanical knowledge are based on two separate, distinct mechanisms.

Can infants be "taught" to attend to a new physical variable in an event category? The case of height in covering events

As they observe or produce events, infants identify variables that help them predict outcomes in each category of events. How do infants identify a new variable? An explanation-based learning (EBL) account suggests three essential steps: (1) observing contrastive outcomes relevant to the variable; (2) discovering the conditions associated with these outcomes; and (3) generating an explanation for the condition-outcome regularity discovered. In Experiments 1-3, 9-month-old infants watched events designed to "teach" them the variable height in covering events. After watching these events, designed in accord with the EBL account, the infants detected a height violation in a covering event, three months earlier than they ordinarily would have. In Experiments 4-6, the "teaching" events were modified to remove one of the EBL steps, and the infants no longer detected the height violation. The present findings thus support the EBL account and help specify the processes by which infants acquire their physical knowledge.

Young infants' actions reveal their developing knowledge of support variables: converging evidence for violation-of-expectation findings

Violation-of-expectation (VOE) tasks have revealed substantial developments in young infants' knowledge about support events: by 5.5 months, infants expect an object to fall when released against but not on a surface; and by 6.5 months, infants expect an object to fall when released with 15% but not 100% of its bottom on a surface. Here we investigated whether action tasks would reveal the same developmental pattern. Consistent with VOE reports, 5.5- and 6.5-month-old infants were more likely to reach for a toy that rested on as opposed to against a surface; and 6.5- but not 5.5-month-olds were more likely to reach for a toy with 100% as opposed to 15% of its bottom on a surface. Infants at each age thus used their support knowledge to determine whether the toys were likely to be retrievable or to be attached to adjacent surfaces and hence irretrievable. These and control findings extend recent evidence that developmental patterns observed in VOE tasks also hold in action tasks, and as such provide further support for the view that VOE and action tasks tap the same physical knowledge.

Object and event representation in toddlers

Mental representation of absent objects and events is a major cognitive achievement. Research is presented that explores how toddlers (2- to 3-year-old children) search for hidden objects and understand out-of-sight events. Younger children fail to use visually obvious cues, such as a barrier that blocks a moving object's path. Spatiotemporal information provided by movement cues directly connected to the hidden object is more helpful. A key problem for toddlers appears to be difficulty in representing a spatial array involving events with multiple elements.