Better Than Concrete: Implications for the Psychological and Neural Representation of Concrete Concepts Sarah D. Breedin, Eleanor M. Saffran, and H. Branch Coslett Center for Cognitive Neuroscience, Department of Neurology, Temple University Vol. 8, No. 2, April 1994 Analogic and Metaphoric Mapping in Blended Spaces: Menendez Brothers Virus Seana Coulson Department of Cognitive Science, UCSD Vol. 9, No. 1, February 1995 In Search of the Statistical Brain Javier Movellan Department of Cognitive Science, UCSD Vol. 9, No. 2, March 1995 Connectionist Modeling of the Fast Mapping Phenomenon Jeanne Milostan Computer Science and Engineering, UCSD Vol. 9, No. 3, July 1995 Representing the Structure of a Simple Context-Free Language in a Recurrent Neural Network: A Dynamical Systems Approach Paul Rodriguez Department of Cognitive Science, UCSD Vol. 10, No. 1, October 1995 A Brain Potential Whose Latency Indexes the Length and Frequency of Words Jonathan W. King Co...

Developmental trajectories provide the empirical foundation for theories about change processes during development. However, the ability to distinguish among alternative trajectories depends on how frequently observations are sampled. This study used real behavioral data, with real patterns of variability, to examine the effects of sampling at different intervals on characterization of the underlying trajectory. Data were derived from a set of 32 infant motor skills indexed daily during the first 18 months. Larger sampling intervals (2–31 days) were simulated by systematically removing observations from the daily data and interpolating over the gaps. Infrequent sampling caused decreasing sensitivity to fluctuations in the daily data: Variable trajectories erroneously appeared as step functions, and estimates of onset ages were increasingly off target. Sensitivity to variation decreased as an inverse power function of sampling interval, resulting in severe degradation of the trajectory with intervals longer than 7 days. These findings suggest that sampling rates typically used by developmental researchers may be inadequate to accurately depict patterns of variability and the shape of developmental change. Inadequate sampling regimes therefore may seriously compromise theories of development.

Prior research reports that children up to 3-years-old map novel adjectives to object properties only in very limited situations (Gelman & Markman, 1985; Taylor & Gelman, 1988; Hall, Waxman, & Hurwitz, 1993; Klibanoff &Waxman, 1997; Waxman & Markow, 1997). Yet we know by 24-months children use adjectives. In two experiments we provide 36-month-olds (Experiment 1) and 24-month-olds (Experiment 2) with rich cross-situational and syntactic information. We show that 24- & 36-month-olds learn adjective-to-property mappings when given multiple examples of the mapping, and when object names are used. We claim that previous experiments failed to find robust adjective acquisition because at least one of these sources of information (multiple exemplars) was excluded. We also suggest that children's initial learning about the meanings of adjectives is affected by syntactic properties of the noun phrase in which they appear. Introduction By 24-months of age, children already use a number of adje...