Preferential-looking studies suggest that by 2 months of age, infants may have knowledge about some object properties, such as solidity. Manual search studies of toddlers examining these same concepts, however, have failed to provide evidence for the same understanding. Investigators have recently attempted to reconcile this disparity but failed…

An investigation of Piaget's theory of object concept development through a series of six tasks administered in a combined longitudinal/cross-sectional design (which incorporated a number of methodological controls). Subjects were 36 infants who received the six tasks during each of three testing sessions over a 6-month period. (Author/ED)

Presents a study of decalage between object permanence and person permanence. Decalage was influenced by environmental as well as stimulus factors with infants tested between 6- and 81/4-months/of-age. (BD)

The relationship between the development of object permanence and early words was studied in three young boys, two totally blind from birth and one severely visually impaired. Subjects acquired early words within the age range for sighted children but their word usage was different. The two blind children were delayed in their development of…

A fundamental question of perceptual development concerns how infants come to perceive partly hidden objects as unified across a spatial gap imposed by an occluder. Much is known about the time course of development of perceptual completion during the first several months after birth, as well as some of the visual information that supports unity…

The present research examined alternative accounts of prior violation-of-expectation (VOE) reports that young infants can represent and reason about hidden objects. According to these accounts, young infants' apparent success in these VOE tasks reflects only novelty and familiarity preferences induced by the habituation or familiarization trials…

While very young children's understanding of objects as symbols for other entities has been the focus of much investigation, very little is known concerning the emergence of comprehension for symbolic relations among actions modeled with toy replicas and their real counterparts. We used videotaped depictions of real actions in a preferential…

Stimulus preference assessments for individuals with developmental disabilities typically involve offering choices among stimuli and providing immediate access to the chosen stimuli. Several researchers have explored the utility of presenting choices verbally, thereby obviating the need to present the choices in tangible form and deliver access to…

This study measured infant responses to mother and stranger as a function of mother and stranger distance. A group of 10-month-old infants were pretested for level of object permanence and person permanence, and 18 males and 18 females were chosen as study participants. The infants were randomly assigned to one of three treatment groups: (1)…

Nine- to 18-month-old infants were presented with simple two-location manual search tasks involving invisible displacements of objects with sequence of displacements occurring before infants search. Results provided insights into age differences associated with development of logical search strategies, information-processing skills, and temporal…

Observed the reactions of 3.5-month-old infants looking at a carrot that should have but did not appear in a window after passing behind a screen. The results of this and several similar experiments indicated that 3.5-month-old infants are able to represent and reason about hidden objects. (BC)

Twenty congenitally blind infants were placed in a panelled framework with various tactile and auditory objects for 20-minute periods. Results indicated that subjects improved their performance of spatially related activities when exposed to an environment helping them understand the concept and permanence of objects and the production of…

This study examined the effect of a salient multimodal reinforcer on object search performance of 9 children with Down's syndrome (24-56 months old). Attentional deficits of children with mental retardation or at risk for delay influenced their performance. Contingency learning of children with Down's syndrome may be affected by the attentional…

Eight experiments were conducted to examine 3- and 3.5-month-old infants' responses to occlusion events. The results revealed two developments, one in infants' knowledge of when objects should and should not be occluded and the other in infants' ability to posit additional objects to make sense of events that would otherwise violate their…

Infants follow the gaze direction of others from the middle of the first year of life. In attempting to determine how infants understand the looking behavior of adults, a number of recent studies have blocked the adult's line of sight in some way (e.g. with a blindfold or with a barrier). In contrast, in the current studies an adult looked behind…