Nine adults with Prader-Willi syndrome (PWS) and nine age- and IQ-matched adults with PWS completed standardized tests of long-term and short-term memory, visual and auditory processing, and reading and mathematics achievement. Contrary to previous findings, long-term memory in PWS subjects was strong relative to IQ and there was no evidence that…

Two experiments explored the nature of perceptual development in 5- and 10-year olds and adults. The primary finding was that preassessed salience significantly influenced 5-year olds' ability to discriminate two objects, while salience did not affect 10-year olds' or adults' response times. Results showed that salience effects in perceptual…

Three experiments explored 5- and 7-month-olds' intermodal coordination of proprioceptive information produced by leg movements and visual movement information specifying these same motions. Results suggested that coordination of visual and proprioceptive inputs is constrained by infants' information processing of the displays and have…

Two experiments examined developmental changes in reasoning about intensive quantities--predicting mixture intensity of pairs of liquids with different intensities of red color. Results showed that cognitive averaging in this domain developed late and slowly. Predominating up to 12 years was an extensivity bias, a strong tendency to use rules that…

We addressed the hypothesis that word segmentation based on statistical regularities occurs without the need of attention. Participants were presented with a stream of artificial speech in which the only cue to extract the words was the presence of statistical regularities between syllables. Half of the participants were asked to passively listen…

The purpose of the present study was to determine whether playing a specific ball sport, such as tennis, could maintain the coincidence-timing (CT) performance of older adults at a similar level to that of younger ones. To address this question, tennis players and nonplayers of three different age ranges (ages 20-30, 60-70, and 70-80 years)…

The aim of this article is to introduce readers to an alternative way of applying U-shaped functions to understand development, especially cognitive development. In classical developmental applications, age is the abscissa; that is, in the fundamental equation B = f(A), some behavioral variable (B) plots as a U-shaped or inverted U-shaped function…

The articles in this collection consider one very interesting puzzle of development: U-shaped developmental functions. At some point during development, an organism might exhibit what seems like a regression from its expected developmental trajectory and, according to continuity models of development, this is aberrant. In this special issue,…

The "visual world paradigm" typically involves presenting participants with a visual scene and recording eye movements as they either hear an instruction to manipulate objects in the scene or as they listen to a description of what may happen to those objects. In this study, participants heard each target sentence only after the corresponding…

How do infants individuate and track objects, and among them objects belonging to their species, when they can only rely on information about the properties of those objects? We propose the Human First Hypothesis (HFH), which posits that infants possess information about their conspecifics and use it to identify and count objects. F. Xu and S.…

Research during the past decade lends support to the notion that visual as well as phonological deficits are significantly correlated with reading and learning disorders. However, from the variety of visual anomalies discussed, it soon becomes evident that vision, itself, is not a unitary disorder. In this review, the multifaceted nature of…

Writing treatment that involved repeated copying and recall of target words was implemented with 8 individuals with severe aphasia in order to discern the best candidates for the treatment. Four of the 8 participants had strong positive responses to the copy and recall treatment (CART), relearning spellings for 15 targeted words during 10 to 12…

The academic achievement of boys with fragile X syndrome and the relation between several predictive factors and academic performance are reported. Boys with fragile X syndrome displayed significant deficits in all academic skill areas. Relative strengths were observed in general knowledge, reflecting the ability to integrate experiential…

This research is an effort to best utilize the interactive anatomical images for instructional purposes based on cognitive load theory. Three studies explored the differential effects of three computer-based instructional strategies that use anatomical cross-sections to enhance the interpretation of radiological images. These strategies include:…

This follow-up study compares cognitive and language aspects of a group of Italian children ages 4-6 years, who had shown delayed expressive language abilities at 24 months of age (late talkers), with those of a group of children with a history of normal expressive language development (average talkers). Children were given a battery of…