Intonation in the monosyllabic utterances of 1-year-olds

Previous research has demonstrated that falling contours predominate in infant utterances as early as 3 months of age. The precocious appearance of falling intonation is usually attributed to “biological tendencies,” that is, the physiological naturalness of descending fundamental frequency patterns. In contrast, other investigations have shown that some children do not use adultlike falling or rising intonation contours until they produce their first words. To resolve these conflicting views of prosodic development, this study acoustically investigated intonation production in the monosyllabic utterances of 10 English-speaking children from 10 to 13 months of age and the utterance-final monosyllables of ten 4-year-olds. Children in both age groups produced a wider accent range in falling contours than in rising contours. Infants produced a narrower accent range than the preschoolers. The findings suggest that biological tendencies are not sufficient to account for children’s acquisition of intonation between the ages of 1 and 4 years.     

Priming infants to attend to color and pattern information in an individuation task

Wilcox (Cognition 72 (1999) 125) reported that infants are more sensitive to form than surface features when individuating objects in occlusion events: it is not until 7.5 months that infants spontaneously use pattern information, and 11.5 months that they spontaneously use color information, as the basis for object individuation. The present research assessed the extent to which infants' sensitivity to surface features could be increased under more supportive conditions. More specifically, we examined whether younger infants could be primed to draw on color and pattern features in an individuation task if they were first shown the functional value of attending to color and pattern information (i.e. the color or the pattern of an object predicted the function it would engage in). Five experiments were conducted with infants 4.5 to 9.5 months of age. The main findings were that 9.5- and 7.5-month-olds could be primed to use color information, and 5.5- and 4.5-month-olds could be primed to attend to pattern information, after viewing the function events. The results are discussed in terms of the kinds of experiences that can lead to increased sensitivity to surface features and the mechanisms that support feature priming in young infants.     

Infants track action goals within and across agents

The ability to understand that goals and other intentional relations are attributes of individual people is of fundamental importance to social life. It enables us to predict and interpret actions on-line by relating a person's prior and current behaviors, and distinguishing them from the behaviors of other persons. In this paper, we consider the origins of the ability to mark goals as attributes of individual people. Using a visual habituation paradigm to assess infants' tracking of goals, we tested whether infants represented goals are specific to particular agents. Thirteen-month-old infants restricted reaching goals to particular agents, but generalized a conventional linguistic action, labeling, across agents. Nine-month-old showed the former pattern but not the latter. We discuss these findings in the context of developing understandings of person specific and person general action knowledge.     

Physical activity in infants with Down syndrome receiving a treadmill intervention

Despite the recognized relevance of physical activity in the development and health of children, assessment of physical activity levels (PA-level) in infancy is limited, especially in infants with Down syndrome (DS). Increasing PA-level using a treadmill training (TMT) intervention may benefit infants with motor delays. The purpose of this study was to investigate whether a higher intensity, individualized TMT protocol (HI) would elicit immediate and short-term higher PA-level in infants with DS than a lower intensity, generalized training protocol (LG).Thirty infants with DS were randomly assigned to the LG or the HI group. Training was terminated when the infants could walk three steps independently. Activity monitors were placed on infants’ trunks and legs for a 24-h period every other month during the intervention phase, and at set intervals 1-year post-independent walking onset. Data were analyzed to separate sedentary-to-light activity (Lowact) and moderate-to-vigorous activity (Highact).Overall our results demonstrate that infants receiving the HI TMT had higher levels of Highact than infants in the LG group, factoring out the activity produced by the intervention itself. Infants in the LG group spent more time in Lowact than the HI group. In addition, these results seemed to be retained during the post-intervention follow-up. Despite these exciting results, more work is needed to understand the relationship of the intensity of TMT on PA-level in infants with DS, and whether PA-level and TMT are related to motor milestone achievement and/or health benefits.     

Linking sounds to meanings: Infant statistical learning in a natural language

The processes of infant word segmentation and infant word learning have largely been studied separately. However, the ease with which potential word forms are segmented from fluent speech seems likely to influence subsequent mappings between words and their referents. To explore this process, we tested the link between the statistical coherence of sequences presented in fluent speech and infants’ subsequent use of those sequences as labels for novel objects. Notably, the materials were drawn from a natural language unfamiliar to the infants (Italian). The results of three experiments suggest that there is a close relationship between the statistics of the speech stream and subsequent mapping of labels to referents. Mapping was facilitated when the labels contained high transitional probabilities in the forward and/or backward direction (Experiment 1). When no transitional probability information was available (Experiment 2), or when the internal transitional probabilities of the labels were low in both directions (Experiment 3), infants failed to link the labels to their referents. Word learning appears to be strongly influenced by infants’ prior experience with the distribution of sounds that make up words in natural languages.     

A Piagetian approach to infant referential behaviors

Near the end of the first year of life, infants begin producing referential behaviors that in adults indicate joint attention, or coordinating shared attention to an object with another person. These behaviors have been interpreted in the social cognitive literature as an indication that infants realize they are sharing attention to an object with another person. In this paper, we address theory and research on infant referential behaviors described as joint attention and offer an alternative explanation for the presence of these behaviors. Using Piaget's constructivist theory, we show how research in this area can be interpreted without assuming that infants have advanced social cognitive abilities. We argue that infants’ referential behaviors are motor signifiers of thought and that infants recognize humans as particularly relevant objects for their goal-directed behaviors. Finally, we describe how the field of infant joint attention research should proceed if a comprehensive understanding of infant cognitive processes is to be desired.     

A prelinguistic gestural universal of human communication

Several cognitive accounts of human communication argue for a language-independent, prelinguistic basis of human communication and language. The current study provides evidence for the universality of a prelinguistic gestural basis for human communication. We used a standardized, semi-natural elicitation procedure in seven very different cultures around the world to test for the existence of preverbal pointing in infants and their caregivers. Results were that by 10-14 months of age, infants and their caregivers pointed in all cultures in the same basic situation with similar frequencies and the same proto-typical morphology of the extended index finger. Infants' pointing was best predicted by age and caregiver pointing, but not by cultural group. Further analyses revealed a strong relation between the temporal unfolding of caregivers' and infants' pointing events, uncovering a structure of early prelinguistic gestural conversation. Findings support the existence of a gestural, language-independent universal of human communication that forms a culturally shared, prelinguistic basis for diversified linguistic communication.     

Infants' reasoning about opaque and transparent occluders in an individuation task

There has been some debate about whether infants 10 months and younger can use featural information to individuate objects. The present research tested the hypothesis that negative results obtained with younger infants reflect limitations in information processing capacities rather than the inability to individuate objects based on featural differences. Infants aged 9.5 months saw one object (i.e. a ball) or two objects (i.e. a box and a ball) emerge successively to opposite sides of an opaque occluder. Infants then saw a single ball either behind a transparent occluder or without an occluder. Only the infants who saw the ball behind the transparent occluder correctly judged that the one-ball display was inconsistent with the box-ball sequence. These results suggest that: (a) infants categorize events involving opaque and transparent occluders as the same kind of physical situation (i.e. occlusion) and (b) support the notion that infants are more likely to give evidence of object individuation when they need to reason about one kind of event (i.e. occlusion) than when they must retrieve and compare categorically distinct events (i.e. occlusion and no-occlusion).     

Beyond the information given: Infants’ transfer of actions learned through imitation

Five experiments were conducted to investigate infants’ ability to transfer actions learned via imitation to new objects and to examine what components of the original context are critical to such transfer. Infants of 15 months observed an experimenter perform an action with one or two toys and then were offered a novel toy that was not demonstrated for them. In all experiments, infants performed target actions with the novel toy more frequently than infants who were offered the same toy but had seen no prior demonstrations. Infants exhibited transfer even when the specific part to be manipulated looked different across the toys, even when they had not performed the actions with the demonstration toys themselves, even when the actions produced no effects on the demonstrations, and even when the actions were demonstrated with only a single exemplar toy. Transfer was especially robust when infants not only observed but also practiced the target actions on the demonstration trials. Learning action affordances (“means”) seems to be a central aspect of human imitation, and the propensity to apply these learned action affordances in new object contexts may be an important basis for technological innovation and invention.