Two experiments compared 6-month-olds' numerosity discrimination performance on both large numbers and small numbers with both total filled area and total contour length controlled. Results showed that infants succeeded in discriminating 4 from 8 elements, but failed to discriminate 2 from 4 elements, providing evidence for the existence of two…

Two studies examined whether object names and functions act as cues to categories for infants. Findings indicated that both 14- and 18-month-olds were more likely to select the category match after being shown a novel category exemplar with its function than when given no additional cues. Only at 18 months did naming the objects enhance…

Examined in two studies infants' reenactment of intended acts in failed-attempt paradigm. Found that when only first actions were counted, infants who observed the full-demonstration model produced more target acts. When all target acts produced within the response period were counted, infants in emulation-learning and spatial contiguity…

Investigated 4- and 7-month-olds' perception of transparency, using computer-generated achromatic or color displays depicting a semitransparent box occluding the center of a rod. Found that 4-month-olds indicated perception of transparency in color but not in achromatic displays. Seven-month-olds showed some evidence of transparency perception in…

Two studies investigated whether 10- to 11-month-olds possess skills for parsing ongoing behavior along boundaries correlated with initiation and completion of intentions. Found that infants showed renewed interest in test videos in which motion paused in the midst of an actor's pursuit of intentions; suspended motion at intentional boundary…

Three experiments assessed the extent to which statistical learning generates novel word-like units, rather than probabilistically-related strings of sounds. Found that 8-month-olds' listening preferences were affected by the context (English versus nonsense) in which items from the familiarization phase were embedded during testing. Confirmed…

Reveals that different aspects of the environment differentially contributed to variability in communication performance of one-year-old infants. Findings support the environmental specificity hypothesis and underline the need to consider physical environmental parameters when investigating environmental influences. (Author/RH)

Examined whether 6-month-olds expect people to behave differently toward persons and inanimate objects. Found that infants habituated to an actor talking to something hidden behind an occluder looked longer at an object, whereas infants habituated to an actor reaching and swiping looked longer at a person. No difference in looking at stimuli was…

Three experiments examined the memory-preserving effects of reactivation and reinstatement reminders following 6-month-olds' learning and forgetting of an operant task. Findings indicated that a single reactivation reminder extended infants' memory of an operant mobile task for 2 weeks, a single reinstatement extended it for 4 weeks. A single…

Two studies assessed the gaze following of 12-, 14-, and 18-month-olds. Findings indicated that infants at all ages looked at the adult's target more when the adult turned to the target with open eyes than when the adult turned with closed eyes. Additional evidence suggested that infants were not simply responding to adult head turning, but were…

Calm or crying 9- and 12-week-olds sat facing a researcher who gazed into their eyes or at their forehead and delivered either a sucrose solution or pacifier or delivered nothing. Found that combining sweet taste and eye contact was necessary and sufficient for calm 9- and 12-week-olds to form a preference for the researcher, but not for crying…

Two experiments examined memory of 7-month-olds after 2-week retention interval for passages of two Mozart movements heard daily for 2 weeks. Results suggested that the infants retained familiarized music in long-term memory and that their listening preferences were affected by the extent to which familiar passages were removed from the musical…

Examined role of social-referential context in 13- and 18- month-olds' mapping of verbal and nonverbal symbols to object categories. Found that infants at both ages showed evidence of learning both words and sounds when the experimenter produced a label within a familiar naming routine, and failed to learn when labels were emitted from a baby…

Two experiments examined problem solving in 16-month-olds' adaptive locomotion (crossing bridges of varying width with/without handrail). Findings indicated that toddlers attempted wide bridges more than narrow ones. Attempts on narrow bridges depended on handrail presence. Toddlers had longer latencies, examined bridge/handrail more closely, and…

Four experiments examined whether reinstatement and reactivation reminder paradigms affected memory performance of 102 three-month-olds. Results indicated that a single reinstatement protracted retention twice as long after training as a single reactivation. The novelty of the reminder stimulus also affected duration and specificity of memory in…