One question fundamental to understanding human cognition is how to conceptualize the nature and development of early knowledge. Research conducted in the Infant Cognition Lab focuses on object knowledge, the aspects of this knowledge that infants possess very early and those that are acquired more gradually, and the mechanisms that support knowledge acquisition during the first year. The physical world is a complex multimodal environment and there are many factors that can influence the way in which infants perceive, interpret, and use incoming information. In order to better understand how this changes with time and experience, we have studied object processing from multiple perspectives using convergent methods of study, including violation-of-expectation paradigms, eye tracking technology, action tasks, and near-infrared spectroscopy.Our research is supported by the National Science Foundation and the National Institutes for Child Health and Human Development
Object Individuation and Knowledge Acquisition
Much of our research on object knowledge has focused on infants’ developing capacity to individuate objects. The physical world provides infants with a wealth of information about objects and their properties. At the same time, as infants move about in the world, perceptual contact is often lost and then regained. The dynamic nature of the physical world presents infants with the challenge of determining whether an object currently in view is the same object or a different object than seen before. The outcome of this process determines how infants perceive, think about, and act on objects and forms the basis for more complex cognitive processing.
Research conducted in our lab has revealed developmental hierarchies, in both the visual and the auditory domain, in the type of information to which infants are most sensitive when faced with an individuation problem. For example, in the visual domain infants are more sensitive to form features, such as shape and size, than surface features, such as color, pattern, and luminance. We have suggested that developmental hierarchies are best explained by the way in which the physical world is structured and infant’s experiences in the physical world. Consistent with this perspective, we have identified select experiences that can alter these early sensitivities. Analysis of the kinds of experiences that alter the type of information to which infants attend, and the specific conditions under which these experiences are most effective, sheds light on the mechanisms that support knowledge acquisition in infancy. Within this context we have studied the role of categorization, comparison, multimodal processing, and postural support on object representation and knowledge in infants.
Another component of this work investigates infants’ emerging capacity to map one object-related event representation onto another. A number of factors, including complexity of the event to be mapped, infant’s ability to extract the simple structure of the event, and the kind of information that must be mapped, can influence event-mapping. In addition, we have identified individual and group differences in event-mapping abilities. We are currently using eye tracking technology to identify specific processes that underlie the differences observed.
Brain and Cognition
Over the last 30 years behavioral studies have revealed a great deal about the development of object processing during the first year of life. In contrast, comparatively little is known about the underlying neural mechanisms that are responsible for the changes observed in behavioral tasks. One reason for this gap in knowledge is that there are a limited number of non-invasive neuroimaging techniques available for use with infants, limiting investigators in their efforts to systematically explore the functional development of object processing pathways. The recent introduction of near-infrared spectroscopy (NIRS), an optical imaging technique that uses changes in blood flow and oxygenation as an indicator of neural activation, into the experimental setting now offers infant researchers this opportunity.
Studies conducted in our lab were some of the first to establish the feasibility of using NIRS to study perceptual and cognitive processing in awake, active infants. Since then we have identified distinct patterns of neural activation associated with processing of shape and color information in the infant. For example, young infants, who are more likely to use shape than color information to individuate objects, show greater neural activation to shape than color differences in anterior areas of the temporal cortex. Older infants, who use both shape and color information to individuate objects, show increased neural activation in the temporal cortex to both features. We have also obtained a dissociation of processing of featural and spatiotemporal information in the cortex. For example, young infants show greater neural activation in parietal cortex to spatiotemporal discontinues than to featural differences. Recently we have begun investigating the neural basis of infants’ capacity to extract three-dimensional object shape from coherent motion and contour. Collectively, this area of research is critical to the development of brain-behavior models of perceptual and cognitive development and allows us, for the first time, to specify the relation between neural activation and specific components of object processing in the human infant.
Learning within the Social Context
Babies are continuously learning about their world and much of this learning takes place in the presence of others. Parents and caretakers often facilitate learning during day-to-day interactions with their infants using everyday objects. Hence, one area of our research focuses on how babies learn within the context of the social world. For example, one project investigates how infants learn to use color for knowing that one object is different from another object (object individuation). Current results indicate that infants are more likely to learn when a parent, as compared to an unfamiliar adult, demonstrates the value of attending to an object’s color. Another project examines infant-parent interactions during a free play setting. In these studies we are investigating the ways in which parents guide infants’ object exploration in a free play situation, the extent to which this influences the type of information that infants gain about objects, and the degree to which the nature of the parent-infant relationship influences this process. The main goal of this work is to identify components of the social context that are particularly effective in facilitating knowledge acquisition in infants.
One important component of social interaction is using the emotional expressions of others to guide behavior. When faced with a new situation, infants often use their parents affect to guide their appraisal of the situation and to choose their own behavioral responses. For example, if a parent displays a positive emotion in a new situation (i.e. smiles and seems relaxed), then his or her infant will most likely show a similar response. Another area of our research focuses on emotional communication between adults and infants. In one project, infants are presented with the opportunity to play with toys that they have never seen before. First, however, a parent or an unfamiliar adult directs a positive, disgust, fearful, or a neutral emotion and dialogue towards different toys. Then, the infants are allowed to crawl to the toys and pick one for play. By observing which object the infant chooses, and the length of time it takes them to choose, we can learn more about how an adults expressed emotion influences an infants behavior and guides the kinds of experiences the infant has with toys.