Structural packaging in the input to language learning: Contributions of prosodic and morphological marking of phrases to the acquisition of language

The linguistic input to language learning is usually thought to consist of simple strings of words. We argue that input must also include information about how words group into syntactic phrases. Natural languages regularly incorporate correlated cues to phrase structure, such as prosody, function words, and concord morphology. The claim that such cues are necessary for successful acquisition of syntax was tested in a series of miniature language learning experiments with adult subjects. In each experiment, when input included some cue marking the phrase structure of sentences, subjects were entirely successful in learning syntax; in contrast, when input lacked such a cue (but was otherwise identical), subjects failed to learn significant portions of syntax. Cues to phrase structure appear to facilitate learning by indicating to the learner those domains within which distributional analyses may be most efficiently pursued, thereby reducing the amount and complexity of required input data. More complex target systems place greater premiums on efficient analysis; hence, such cues may be even more crucial for acquisition of natural language syntax. We suggest that the finding that phrase structure cues are a necessary aspect of language input reflects the limited capacities of human language learners; languages may incorporate structural cues in part to circumvent such limitations and ensure successful acquisition.     

Cognitive processing of tokens and their description in aphasia

In a dual-reaction time task aphasics (N = 21) and right-hemisphere (RH) controls (N = 24) had to decide whether a list of features given verbally or pictorially correctly described the picture of a token. Although the error rates were extremely low, aphasics made significantly more errors than RH controls. There were no significant differences between the groups in latencies when pictures of tokens were presented; the groups differed drastically, however, when confronted with lists of features. The findings are interpreted as indicating a general deficit in the short-term storage of highly specific information.     

Development of visuomanual tracking in 5- to 9-year-old boys

Visuomanual sinusoidal tracking is investigated in 5- to 9-year-old children. The proportion of successful performances steadily increases with age, but adult proficiency is never attained even by those who can perform the task. Moreover, the progress in proficiency—as measured by systems analysis techniques—is not monotonic and suggests the presence of distinct stages in the development of visuomotor coordination. Qualitative analysis of unsuccessful performance demonstrates that failures cannot be ascribed only to insufficient motor coordination and emphasizes the role of cognitive and representational factors even in such a simple task.     

Manual Movement in Sign Languages: One Hand Versus Two in Communicating Shapes

In sign languages, the task of communicating a shape involves drawing in the air with one moving hand (Method One) or two (Method Two). Since the movement path is iconic, method choice might be based on the shape. In the present studies we aimed to determine whether geometric properties motivate method choice. In a study of 17 deaf signers from six countries, the strongest predictors of method choice were whether the shape has any curved edges (Method One), and whether the shape is symmetrical across the Y‐axis (Method Two), where the default was Method One. In a second study of ASL dictionary entries for which the movement path of the sign is iconic of an entity's shape, the same predictors surfaced. These tendencies are captured in the Lexical Drawing Principle, which is coherent with biological constraints on movement in general. Drawing in the air with two hands, however, is costly, both cognitively and biomechanically. Furthermore, it distinguishes signers from non‐signers, who draw shapes with only one hand. Signers assume this extra cost in the lexicon because of the enhanced iconicity the possibility of two hands offers; they assume it in drawing shapes in the air because they apply the same linguistic principle they use in the lexicon. Additionally, having a choice of methods allows the signer to benefit from over‐specification in providing redundant information about the shape, enhancing comprehensibility and resolving ambiguity.