Final Report Summary - ON THE OTHER HAND (On the other hand: the linguistic impact of having two symmetrical articulators in sign language)
Deaf people communicate with two hands, while hearing people speak with only one mouth. The present project investigated some of the implications of this difference for our view of human language. Linguistic models are generally based on the fact that spoken language structures are linear and hierarchically structured. The symmetry of the two hands in signed languages makes room for abundant simultaneity, even though our motor system imposes severe constraints on the independent action of the two hands. We know that deaf people rarely utter two different sentences at the same time (one with the left and one with the right hand), but there were indications that from below the level of single signs up to the structuring of discourse, the two hands contribute to communication in a fashion unparalleled in spoken languages. In our studies of Sign Language of the Netherlands (NGT, or Nederlandse Gebarentaal), we found that in so-called classifier constructions, two independent very brief sentences are articulated simultaneously, each hand expressing a predicate that may each have different arguments. More commonly, the non-dominant hand holds information for a while as the other, dominant, hand continues to sign. These holds were observed to occur both within sentences and also across sentences, suggesting a manual rhythm that sometimes consists of units larger than a single sentence. Although this was not foreseen, we found extensive evidence for the fact the dominant hand in a specific sign or sentence need not correspond to a person’s preference hand. Signers are very apt to reverse the role of the two hands, even though the frequency with which such dominance reversals occur varies considerably across the 92 individuals in the Corpus NGT, the primary data set used for our studies. While signers may switch dominance for no communicative reason, it seems that the majority of reversals for most people does actually have a function, typically to express contrast at some level of the grammar.
Aside from the research publications, the project has also yielded a large database of annotations that will be available to researchers and general public alike, as well as a basic lexicon related to these annotations. Both are already being exploited for teaching and learning. A series of popular publications for both deaf signers (in sign language) and hearing learners has made the existence of the data sets known to a broad audience and has suggested ways for non-research exploitation.
Aside from the research publications, the project has also yielded a large database of annotations that will be available to researchers and general public alike, as well as a basic lexicon related to these annotations. Both are already being exploited for teaching and learning. A series of popular publications for both deaf signers (in sign language) and hearing learners has made the existence of the data sets known to a broad audience and has suggested ways for non-research exploitation.