Scott A. Johnson - US grants

DESCRIPTION (provided by applicant): Thirteen experiments investigate the early development of the ability to learn patterns in sequential input. Such evidence would seem likely to provide a substantial contribution to our knowledge of how infants identify both concrete and abstract patterns, a fundamental aspect of cognitive development. The proposed experiments are organized into three broad studies. In the first study, we will examine "ancillary" factors that may influence sequence learning in infancy. We emphasize the importance of two kinds of relations between elements in any multi-element group or string: itemwise relations, between specific instances (e.g., statistical learning), and variablewise relations, between algebraic placeholders (e.g., abstract pattern or rule learning). We argue that a first step toward any programmatic series of experiments on these kinds of learning-must involve an understanding of processing limitations that may constrain performance. In the second study, we will investigate the different kinds of patterns infants may be able to learn, using past and pilot data as a guide for our theorizing. In the final study, we will explore the intriguing possibility that infants may learn more than one pattern in any single set of inputs, a classic question that has received little empirical attention in the literature on cognitive development. The short-term objectives of the present proposal are to elucidate fundamental developmental mechanisms in the ability to detect abstract visual and auditory structure. The long-term goals are to shed light on the larger question of how knowledge is acquired and structured in the human, how perceptual skills impact knowledge acquisition and structure, and how to best characterize early development. In the future, such understanding may aid in the formulation of diagnostics and treatments for some developmental disorders.

It is essential to identify the early signs of autism spectrum disorders (ASD) in order to improve developmental outcomes. While recent evidence suggests that the assessment of a wide range of skills and behaviors may help identify signs of ASD in the second year of life, the search for behavioral markers of ASD in the first 12 months has proven particularly challenging. This challenge is likely due to the limited behavioral repertoire of infants in the first year of life, thus motivating the search for more sensitive biomarkers. Informed by our own (and others') work on the neural basis and early indicators of ASD, the overarching aim of Project I is to identify reliable biological markers of ASD in infants at ultra-high risk (UHR) for the disorder, i.e. having more than one older sibling with ASD. We are taking an innovative, hypothesis driven, multi-modal approach, which uses eye tracking, pupillometry, electrophysiology (EEG), and magnetic resonance imaging (MRI) to track these infants' development in the first year of life, with focus on social attention, implicit learning, and brain connectivity. Accordingly, we will quantify the development of attention to, and engagement with, socially relevant stimuli, using eye-tracking and pupillometry paradigms capturing dynamic social interactions. We will examine the neural correlates of implicit learning using innovative event-related electrophysiological measures and functional MRI. And we will characterize the development of functional and structural connectivity using EEG and MRI. Overall, we expect to detect altered developmental pathways in these social and cognitive domains and neural processes in UHR infants, as compared to low risk infants (LR), and that the proposed measures will be predictive of an ASD diagnosis at 36 months.

DESCRIPTION (provided by applicant): Visual statistical learning is the process of identifying patterns of probabilistic co-occurrence among visual features, essential to our ability to perceivethe world as predictable and stable. The proposed experiments will provide the first comprehensive examination of infants' detection of complex statistical patterns in visual sequences and layouts b describing computation of probabilistic information by infants from 2 to 14 months. This is a formaive time in perceptual and cognitive development characterized by rapid developmental change in perception and learning of environmental structure. In particular, the experiments will examine how structural variability, cognitive load, and memory limitations affect learning, how contextual cues facilitate or impede this learning, and whether the products of such learning can be generalized toa different setting. In addition, the experiments will provide critical tests of domain-specificity b examining the specific contributions of spatial information to visual statistical learning. The shot-term objectives of the proposed research are to learn how developing perceptual and cognitive skills intract in early development to identify statistically defined patterns. The long-term goals are to clarifytheories of cognitive development that posit a central role for inductive learning by computing probabilitie of observations. The results of this research may have implications for understanding development in children who may be at risk for developmental disorders such as iron-deficiency anemia and autism spectrum disorders, both of which have been characterized as deficits in implicit learning. Such an understanding may lead to assessment tools more closely tailored to early diagnosis and treatment than are presently available. PUBLIC HEALTH RELEVANCE: Visual statistical learning is the process of identifying patterns of probabilistic co-occurrence among visual features, essential to our ability to perceive the world a predictable and stable. The proposed experiments will provide the first comprehensive examination o infants' detection of complex statistical patterns in visual sequences and layouts by describing computation of probabilistic information by infants from 2 to 14 months. This research will bring nw findings and new theoretical perspectives to longstanding debates about the origins of knowledge, ad may shed light on possible ways of examining atypical development, as when implicit learning is disrupted in infants at risk for autism or iron-deficiency anemia.

? DESCRIPTION (provided by applicant): Social attention is the process of perceiving visual features, such as motion patterns, that specify other people, their distinct characteristics, and their social group memberships, and it is vital to our ability to observe, understand, and participate in social interactions. The proposed experiments will provide the first comprehensive examination of infants' social attention and categorization by describing conditions under which 3- to 12-month-old infants categorize point-light displays produced from recordings of adults from different social groups. This is a formative time in perceptual and cognitive development, and it is characterized by rapid developmental change in perception and learning of environmental structure, including social information. This research will bring new findings and new theoretical perspectives to longstanding debates about the origins of social knowledge and social learning that stem from typical developmental trajectories of visual attention to social stimuli. The short-term objectives of the proposed research are to discover how developing perceptual and cognitive skills yield discrimination, categorization, identification, and learning f biological motion in infancy. The long- term goals are to clarify theories of social categorization and social development and to contribute to characterization of developmental disorders such as autism spectrum disorder, for which there may be specific deficits in social attention. Such an understanding may lead to assessment tools more closely tailored to early diagnosis and treatment than are presently available.