Forging a morphological system out of two dimensions: Agentivity and number

Emergent Morphology in Child Homesign: Evidence from Number Language

Human languages, signed and spoken, can be characterized by the structural patterns they use to associate communicative forms with meanings. One such pattern is paradigmatic morphology, where complex words are built from the systematic use and re-use of sub-lexical units. Here, we provide evidence of emergent paradigmatic morphology akin to number inflection in a communication system developed without input from a conventional language, homesign. We study the communication systems of four deaf child homesigners (mean age 8;02). Although these idiosyncratic systems vary from one another, we nevertheless find that all four children use handshape and movement devices productively to express cardinal and non-cardinal number information, and that their number expressions are consistent in both form and meaning. Our study shows, for the first time, that all four homesigners not only incorporate number devices into representational devices used as predicates , but also into gestures functioning as nominals, including deictic gestures. In other words, the homesigners express number by systematically combining and re-combining additive markers for number (qua inflectional morphemes) with representational and deictic gestures (qua bases). The creation of new, complex forms with predictable meanings across gesture types and linguistic functions constitutes evidence for an inflectional morphological paradigm in homesign and expands our understanding of the structural patterns of language that are, and are not, dependent on linguistic input.

The communicative importance of agent-backgrounding: Evidence from homesign and Nicaraguan Sign Language

Some concepts are more essential for human communication than others. In this paper, we investigate whether the concept of agent-backgrounding is sufficiently important for communication that linguistic structures for encoding this concept are present in young sign languages. Agent-backgrounding constructions serve to reduce the prominence of the agent - the English passive sentence a book was knocked over is an example. Although these constructions are widely attested cross-linguistically, there is little prior research on the emergence of such devices in new languages. Here we studied how agent-backgrounding constructions emerge in Nicaraguan Sign Language (NSL) and adult homesign systems. We found that NSL signers have innovated both lexical and morphological devices for expressing agent-backgrounding, indicating that conveying a flexible perspective on events has deep communicative value. At the same time, agent-backgrounding devices did not emerge at the same time as agentive devices. This result suggests that agent-backgrounding does not have the same core cognitive status as agency. The emergence of agent-backgrounding morphology appears to depend on receiving a linguistic system as input in which linguistic devices for expressing agency are already well-established.

Restrictiveness matters

The Baysian Iterated Learning approach to language is consistent with generative grammar, but needs to be supplemented with specific cognitive constraints for empirical adequacy.

Gesture, sign, and language: The coming of age of sign language and gesture studies

How does sign language compare with gesture, on the one hand, and spoken language on the other? Sign was once viewed as nothing more than a system of pictorial gestures without linguistic structure. More recently, researchers have argued that sign is no different from spoken language, with all of the same linguistic structures. The pendulum is currently swinging back toward the view that sign is gestural, or at least has gestural components. The goal of this review is to elucidate the relationships among sign language, gesture, and spoken language. We do so by taking a close look not only at how sign has been studied over the past 50 years, but also at how the spontaneous gestures that accompany speech have been studied. We conclude that signers gesture just as speakers do. Both produce imagistic gestures along with more categorical signs or words. Because at present it is difficult to tell where sign stops and gesture begins, we suggest that sign should not be compared with speech alone but should be compared with speech-plus-gesture. Although it might be easier (and, in some cases, preferable) to blur the distinction between sign and gesture, we argue that distinguishing between sign (or speech) and gesture is essential to predict certain types of learning and allows us to understand the conditions under which gesture takes on properties of sign, and speech takes on properties of gesture. We end by calling for new technology that may help us better calibrate the borders between sign and gesture.