Attempts to identify the point at which prelinguistic vocalizations are used by infants as a means of communication. A significant relationship between Piagetian causal developmental level and the occurrence of intentional vocalizations was found in a study of 46 infants with a mean age of 10.7 months. (JMB)

Reports on preliminary attempts to find a set of non-linguistic categories in minimally verbal infants. A methodology suitable for the presentation of semantically-defined concepts (agent and recipient) was developed. (Author/ED)

Cognitive categories in infants that have relevance for linguistic development were investigated. "Agent" and "recipient," the categories chosen, are relational categories which by definition involve action. This experiment explored infants' (48 males, 14-24 months of age) sensitivity to certain "action parameters" of events. The question of…

In this study, 50 infants (15 to 18 months of age) were shown four different film sets in an effort to determine (1) whether infants can perceive action role reversals between an actor and recipient of the action when the direction of the action is ruled out as a cue and (2) whether infants consider only animate objects to be potential…