Distractibility is the propensity to behaviorally react to irrelevant information. Although children are more distractible the younger they are, the precise contribution of attentional and motor components to distractibility and their developmental trajectories have not been characterized yet. We used a new behavioral paradigm to identify the…

Age-related increases of speaking rate are not fully understood, but have been attributed to gains in biologic factors and learned skills that support speech production. This study investigated developmental changes in speaking rate and articulatory kinematics of participants aged 4 ("N" = 7), 7 ("N" = 10), 10…

This study examined the relationship of crossing the midline while reaching for objects to the development of bimanual reaching among infants ages 12, 18, and 26 weeks. Findings indicated that the frequency of two-hand grabbing and the number of midline reaches increased with age; most midline reaches were part of two-handed reaches and occurred…

A theory of infant skill acquisition was supported by observations, over a six-week period, of the bouncing activity of eight infants while they were supported in a harness assembly. Observed three stages of activity: an initial assembly stage, when movement was irregular and variable in period; a tuning phase of more periodic movement; a final…

Using a dynamic systems approach, examined the development of intralimb coordination over the first year of independent walking in three infants. Found that, in the first month of walking, there was much instability between the thigh and shank of the leg, but after three months infants appeared to have found an adult-like stable coordinative…

Emphasizes the role that motor development may play in determining developmental sequences in other domains, such as haptic or tactile perception and depth perception. Maintains that there is a high degree of fit between the developmental sequence in which certain perceptual sensitivities unfold and the ages at which the corresponding motor…

Examined longitudinally the effects of infants' age, body dimensions, and experience on the development of crawling. Although most infants displayed multiple crawling postures en route to walking, development did not adhere to a strict progression of obligatory, discrete stages. Duration of experience with earlier forms of crawling predicted the…