Behavioral studies show that infants are capable of discriminating the number of objects or events in their environment, while also suggesting that number discrimination in infancy may be ratio-dependent. However, due to limitations of the dependent measures used with infant behavioral studies, the evidence for ratio dependence falls short of the…

Investigated the possibility that evidence of frequency discrimination might be found when the experimental procedures involved the conjugate reinforcement of nonnutritive sucking. (SDH)

Familiarized 6- and 8-month-olds with speech sounds from a phonetic continuum, exhibiting a bimodal or unimodal frequency distribution. Found that only infants in the bimodal condition discriminated tokens from the endpoints of the continuum. Results demonstrate that infants are sensitive to the statistical distribution of speech sounds in the…

Examined 7- and 9-month-olds' ability to categorize cats and dogs as separate from one another. Found that both groups formed a cat category that included novel cats but excluded a dog and an eagle, and formed a dog category that included novel dogs and a novel cat but excluded an eagle. Results mirrored those of 3- to 4-month-olds with visual…

Two experiments examined six-month-olds' ability to form an abstract containment category. Results indicated that, after habituation to object pairs in a containment relation, infants looked reliably longer at an example of an unfamiliar versus familiar containment relation, indicating that they could form a categorical representation of…

Presented neonates with lexical and grammatical words prepared from natural maternal speech. Found that neonates could categorically discriminate the sets based on a constellation of perceptual cues that distinguished them. Suggested that this ability to discriminate words on basis of multiple acoustic/phonological cues provides a perceptual base…

Research supported in part by OEO Headstart Subcontract No. 1410 with Michigan State University Headstart Evaluation and Research Center.

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…

Two studies examined whether infants' category discrimination in an object-examination task was based solely on an ad hoc analysis of perceptual similarities among the experimental stimuli. Findings indicated that 10- to 11-month- olds' responses varied systematically only with the presence of a category change, but not with the degree of…

Two experiments investigated infants' sensitivity to amount of continuous quantity and to changes in amount of continuous quantity. Found that 6-month-olds looked significantly longer at a novel quantity than at the familiar quantity. Nine-month-olds looked significantly longer at an impossible event than at a possible event. Findings question…

In this paper some behavioral indices of attachment are defined and some of the factors that affect its development are considered. (Editor)

Infants in four age groups--three, six, nine and twelve months--were exposed to an experimental procedure designed to assess the extent to which such subjects were capable of discriminating between different orientations of the same form, and the extent to which they were capable of recognizing the identity between different orientations of the…