Krifka (The origin of topic/comment structure, of predication, and of focusation in asymmetric bimanual coordination, 2006, Interdisciplinary Studies on Information Structure (ISIS): Working Papers of SFB 632 08: 61–96, 2007b) suggests that asymmetric bimanual coordination and ultimately the evolution of lateralization in humans may be the cognitive basis of linguistic topic-comment structure and foreground-background structures in general. As asymmetric bimanual constructions abound in sign languages and are also found in their possible precursors, cospeech gesture and homesign, sign languages may serve (...) as a test ground for the hypothesis. Asymmetric bimanual constructions are indeed used for differentiating foreground and background in sign languages, but some of these constructions are derived from indexical gestures, not manipulation, i.e., they draw on visual attention. Signed topics may be marked by nonmanual features derived from signals of visual attention, and the defining feature of signed topics is eye contact with the addressee, needed to establish a communicative common ground. There, thus, seems to be not one embodied origin of topic-comment structures, but several. Finally, signed topic-comment structure demonstrates how attention shifts in the course of the entire structure, thereby explaining how topics can be described alternately as foreground (e.g., Talmy, Attention phenomena, Oxford University Press, 2007: 265) and background (Jacobs, Linguistics 39: 641–681, 2001). (shrink)

More and more researchers are examining grammar acquisition from theoretical perspectives that treat it as an emergent phenomenon. In this essay, I argue that a robustly developmental perspective provides a potential explanation for some of the well-known crosslinguistic features of early child language: the process of acquisition is shaped in part by the developmental constraints embodied in von Baer’s law of development. An established model of development, the Developmental Lock, captures and elucidates the probabilistic generalizations at the heart of von (...) Baer’s law. When this model is applied to the acquisition of grammar, it predicts that grammatical achievements that are more generatively entrenched will emerge earlier in development and will be more developmentally resilient than those that are less generatively entrenched. I show that the first prediction is supported by a wealth of psycholinguistic evidence involving typically developing children and that the second prediction is supported by numerous studies involving both children who receive deficient linguistic input and children who experience various language impairments. The success of this model demonstrates the analytic potential of a developmental approach to the study of language acquisition. (shrink)