Four experiments studied the perception of the unity and boundaries of objects by 88 4-month-old infants who manipulated them out of the visual field. Infants perceived the unity/boundaries of these objects by detecting the motion patterns they themselves produced. Discrimination between motion patterns transferred from touch to vision. (SLD)

Reports two studies of infant exploration. In the first, age and characteristics of the object stimuli influenced 6-, 9- and 12-month-olds who manipulated a series of objects. Results of the second study suggested that different kinds of manipulation are used to explore changes in shape, texture, and weight. (Author/CB)

The variety of hand grips of 12 children, most of whom were moderately or severely retarded, were classified in order to begin an analysis of hand function. Test reliability was not as great when items were presented to the children as compared to when children were observed or rated by videotape. (FG)

Five infants were studied longitudinally from 18 to 36 weeks of age to determine the extent to which infants use a predictive strategy when reaching for moving objects. (Author/DB)

Researchers observed activities of preschool children engaged in various forms of play, and focused particularly on symbolic play. (Author/DB)

Three-dimensional random polygon objects ranging in complexity between four and 40 turns were presented to the Ss, and time spent in exploration and play was measured over three successive exposure-time blocks. (Author/DLS)

Infants ranging from 6 to 12 months were randomly assigned to one of three conditions: (1) allowed to look at a specified object, (2) allowed to look at and manipulate it, or (3) allowed to look at the object and to manipulate the transparent box in which it was encased. (JMB)

The study compared the performance of 30 blind Chinese children in Taiwan, 34 blind Indian children, and 40 sighted Chinese children on 8 conservation tasks. Although both groups of blind children performed considerably poorer than sighted children, those blind children with considerable experience handling tangible materials performed better than…

This study examined elbow angle during a fine motor task (threading a needle), in the context of positions used in preclinical training exercises and assumed by practitioners performing dental procedures. The 101 subjects tended to choose an obtuse angle (mean of 125 degrees) and to vary this angle only slightly in repeated trials. (DB)

Compared mothers' play with infants with Down syndrome (DSC) and typically developing children (TDC) matched for mental or chronological age. Found that TDC mothers exhibited more object demonstrations with their developmentally younger children, who showed less object play. DSC mothers were more directive and supportive than mothers of younger…

Compared the impact of a small box emitting sounds in response to nearby motion introduced into an infant/toddler and a preschool classroom to illustrate qualitative differences in how children of different ages recognize the same objects as mediating devices for activity. Found that the box became a social object for infants/toddlers and part of…

Two experiments investigated 5-month-old infants' amodal sensitivity to numerical correspondences between sets of objects presented in the tactile and visual modes. A classical cross-modal transfer task from touch to vision was adopted. Infants were first tactually familiarized with two or three different objects presented one by one in their…

The authors investigated the role of perceptual attunement in an emergency braking task in which participants waited until the last possible moment to slam on the brakes. Effects of the size of the approached object and initial speed on the initiation of braking were used to identify the optical variables on which participants relied at various…