Publications (3)3.92 Total impact
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Article: Differences in gait complexity and variability between children with and without developmental coordination disorder.
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ABSTRACT: We used elliptical Fourier analysis (EFA) to examine potential differences in the complexity and variability of gait of children with (N=10) and without (N=10) Developmental Coordination Disorder (DCD). Children with DCD generated movement patters with larger variability and complexity than typically developing (TD) children. In addition, children with DCD exhibited greater asymmetry in their movement patterns compared to TD children. Our results suggest that children with DCD have significantly greater difficulty producing consistent movement patterns both across their left and right legs and over repeated strides. EFA techniques show promise for distinguishing between different groups of individuals.Gait & posture 10/2008; 29(2):225-9. · 2.58 Impact Factor -
Article: Quantifying variability in phase portraits: application to gait ontogeny.
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ABSTRACT: We describe new Fourier- and shape-based methods for quantifying variation in phase-portraits, and re-analyze previously-published ontogenetic and adult data [Clark, J. E., & Phillips, S. J. (1993). A longitudinal study of intralimb coordination in the first year of independent walking: A dynamical systems approach. Child Development, 64, 1143-1157]. Results show considerable variation between individuals and through development, but after 6 months of walking some gait patterns stabilize.Infant behavior & development 04/2008; 31(2):302-6. · 1.34 Impact Factor -
Article: Interactions Between Perceptual and Conceptual Learning
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ABSTRACT: Confusions arise when 'stable' is equated with 'foundational.' Spurred on by the image of a house`s foundation, it is tempting to think that something provides effective support to the extent that it is rigid and stable. We will argue that when considering the role of perception in grounding our concepts, exactly the opposite is true. Our perceptual system supports our ability to acquire new concepts by being flexibly tuned to these concepts. Whereas the concepts that we learn are certainly influenced by our perceptual representations, we will argue that these perceptual representations are also influenced by the learned concepts. In keeping with one of the central themes of this book, behavioral adaptability is completely consistent with representationalism. In fact, the most straightforward account of our experimental results is that concept learning can produce changes in perceptual representations, the 'vocabulary' of perceptual features, that are used by subsequent tasks. This chapter reviews theoretical and empirical evidence that perceptual vocabularies used to describe visual objects are flexibly adapted to the demands of their user. We will extend arguments made elsewhere for adaptive perceptual representations (Goldstone, Schyns, & Medin, 1998; Schyns, Goldstone, & Thibaut, 1998), and discuss research from our laboratory illustrating specific interactions between perceptual and conceptual learning. We will describe computer simulations that provide accounts of these interactions using neural network models. These models have detectors that become increasingly tuned to the set of perceptual features that support concept learning. The bulk of the chapter will be organized around mechanisms of human perceptual learning, and computer simulations of these mechanisms.
