Three experiments investigated use of visual input and body movement input arising from movement through the world on spatial orientation. Experiments involved infants searching for a toy hidden in one of two containers. Findings indicated that search was best after infant movement in a lit environment prior to searching; all other conditions led…

Six experiments examined infants' ability to associate nonsense words with two causal actions: pushing and pulling. Eighteen-month-olds, but not 14-month-olds, formed word-action associations. Fourteen-month-olds discriminated a change in label but not a change in action when the other was held constant. When language labels were replaced with…

Examined 8- to 10-month-olds' responses to standard procedures eliciting joy, fear, anger, and discomfort. Found that response parameters to standard procedures cohered strongly within each episode. Responses cohered across same-emotion episodes, except for anger. Responses and father-reported temperament related to infant's emotional tone in…

Two experiments examined 6-month olds' ability to categorize natural infant-directed utterances. Infants heard seven different tokens from one class of utterance (comforting, approving). Findings indicated that infants who later heard a test stimulus from the unfamiliar class showed response recovery, whereas those who heard a novel stimulus from…

Evaluated infants' ability to form new object categories based on either visual or naming information at 16 and 20 months using an object manipulation task. Found that infants at both ages showed evidence of using visual information to categorize the objects. Only 20-month-olds used naming information. Found a correlation between vocabulary size…

Two experiments examined 8-month-olds' use of absolute and relative pitch cues in a tone-sequence statistical learning task. Results suggest that, given unsegmented stimuli that do not conform to rules of musical composition, infants are more likely to track patterns of absolute pitches than of relative pitches. A third experiment found that adult…

Four-month-old infants from Boston, Dublin, and Beijing were administered the same battery of visual, auditory, and olfactory stimuli. The Chinese infants were significantly less active, irritable, and vocal than the Boston and Dublin samples, with American infants showing the highest level of reactivity. (Author)

Examined the effect of functional values of stimuli on orienting response elicitation. Subjects were 50 4-month-old infants and were randomly assigned to 1 of 3 experimental conditions. Results suggested the importance of taking into account the functional value of stimuli when analyzing infant attention. (MOK)

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…

Examined representation of pictorial exemplars of humans by 3- and 4-month olds. Results demonstrated an asymmetry regarding the exclusivity of categorical representations formed for humans and non-human animals. Categorical representations for humans included exemplar information, whereas categorical representation for non-human animals was based…

Assessed the role of maternal affect mirroring on development of prosocial behaviors and social expectancies in 2- to 3-month-olds. Found that infants whose mothers ranked high on affect mirroring (attention maintenance, sensitivity, responsiveness) ranked high on prosocial behaviors and social expectancy, whereas infants whose mothers ranked low…

Examined infants' emotionality, inside and outside of the relationship with the mother, and mothers' responsiveness as predictors of reunion behaviors in the Strange Situation. Found that children's separation distress mediated influence of predictors and itself predicted reunion behaviors. When distress was controlled, some responses generally…

Investigated whether individual and developmental differences in look duration were correlated with latency to disengage fixation from a visual stimulus for 3- and 4-month olds. Found that look duration was correlated with disengagement latency. Three-month olds showed slower latencies than 4-month olds. Long-looking infants showed greater…

Two experiments examined whether associating an imitation task with an operant task affected 6-month-olds' memory for either task. Results indicated that infants successfully imitated a puppet's action for up to 2 weeks only if the associated operant task (pressing a lever to activate a miniature train) was retrieved first. Follow-up study…

Infants' abilities to identify objects based on their perceptual features develop gradually during the first year and possibly beyond. Earlier we reported [Kaldy, Z., & Leslie, A. M. (2003). Identification of objects in 9-month-old infants: Integrating "what" and "where" information. Developmental Science, 6, 360-373] that infants at 9 months of…