Non-adult-like linguistic behavior in children is sometimes taken as evidence for endogenous factors that drive selection of grammatical features from the child's hypothesis space of possible grammars. Analyses of English-acquiring children's productions of medial "wh"-phrases exemplify this trend in particular. We provide an alternative…

Over the first weeks and months following birth, infants' initial, broad-based perceptual sensitivities become honed to the characteristics of their native language. In this article, we review this process of emerging specialization within the context of a cascading "critical period" (CP) framework, in which periods of maximal openness…

Down syndrome (DS) is associated with abnormalities in multiple organ systems and a characteristic phenotype that includes numerous behavioral features. Language, however, is among the most impaired domains of functioning in DS and, perhaps, also the greatest barrier to independent meaningful inclusion in the community. In this article, we review…

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…

Although there is considerable variability, most individuals with Down syndrome have mental retardation and speech and language deficits, particularly in language production and syntax and poor speech intelligibility. This article describes research findings in the language and communication development of individuals with Down syndrome, first…