Infants' early communicative repertoires include both words and symbolic gestures. The current study examined the extent to which infants organize words and gestures in a single unified lexicon. As a window into lexical organization, eighteen-month-olds' ("N" = 32) avoidance of word-gesture overlap was examined and compared with…

To examine key parameters of the initial conditions in early category learning, two studies compared 5-month-olds' object categorization between tasks involving previously unseen novel objects, and between measures within tasks. Infants in Experiment 1 participated in a visual familiarization-novelty preference (VFNP) task with two-dimensional…

Three-dimensional (3D) object completion, the ability to perceive the backs of objects seen from a single viewpoint, emerges at around 6 months of age. Yet, only relatively simple 3D objects have been used in assessing its development. This study examined infants' 3D object completion when presented with more complex stimuli. Infants…

Positive shyness is a universal emotion with the specific social function of regulating our interactions by improving trust and liking, and showing politeness. The present study examined early infant production of coy smiles during social interactions as a measure of positive shy behavior. Eighty 4-month-olds were experimentally observed during…

Newborn infants preferentially orient to familiar over unfamiliar speech sounds. They are also better at remembering unfamiliar speech sounds for short periods of time if learning and retention occur after a feed than before. It is unknown whether short-term memory for speech is enhanced when the sound is familiar (versus unfamiliar) and, if so,…

Perceptual narrowing--a phenomenon in which perception is broad from birth, but narrows as a function of experience--has previously been tested with primate faces. In the first 6 months of life, infants can discriminate among individual human and monkey faces. Though the ability to discriminate monkey faces is lost after about 9 months, infants…

Three laboratory experiments on social referencing examined whether infants' tendencies to look at and use positive information from the experimenter could be interpreted from a perspective of novelty or expertise. In Study 1, novelty was manipulated. Forty-eight 12-month-old infants participated. In a between-subject design, a more novel or a…

Recent research demonstrated that although 24-month-old infants do well on the initial pairing of a novel word and novel object in fast-mapping tasks, they are unable to retain the mapping after a 5 min delay. The current study examines the role of familiarity with the objects and words on infants' ability to bridge between the initial fast…

This study was designed to examine whether infants acquiring languages that place a differential emphasis on nouns and verbs, focus their attention on motions or objects in the presence of a novel word. An infant-controlled habituation paradigm was used to teach 18- to 20-month-old English-, French-, and Japanese-speaking infants' novel words for…

Two experiments investigated 9-month-old infants' abilities to recognize the correspondence between an actual three-dimensional (3D) object and its two-dimensional (2D) representation, looking specifically at representations that did not literally depict the actual object: schematic line drawings. In Experiment 1, infants habituated to a line…

Infants greatly refine their ability to discriminate language sounds by 12 months, yet 14-month-olds appear to confuse similar-sounding novel words. Two explanations could account for this phenomenon: infants initially have incomplete phoneme representations, suggesting developmental discontinuity; or word-learning demands interfere with use of…

Explanations of variability in long-term recall typically appeal to encoding and/or retrieval processes. However, for well over a century, it has been apparent that for memory traces to be stored successfully, they must undergo a post-encoding process of stabilization and integration. Variability in post-encoding processes is thus a potential…

We examined two aspects of temperamental approach in early infancy, positive reactivity and anger, and their unique and combined influences on maternal reports of child surgency and attention focusing at 4 years of age. One hundred and fourteen infants were observed for their positive reactions to novel stimuli at 4 months, and their anger…

Although research has demonstrated poor visual skills in premature infants, few studies assessed infants' gaze behaviors across several domains of functioning in a single study. Thirty premature and 30 full-term 3-month-old infants were tested in three social and nonsocial tasks of increasing complexity and their gaze behavior was micro-coded. In…

Although individual differences in reactions to novelty in the toddler years have been consistently linked to risk of developing anxious behavior, toddlers' attention toward a novel, putatively threatening stimulus while in the presence of other enjoyable activities has rarely been examined as a precursor to such risk. The current study examined…