Action depiction in Italian Sign Language: a developmental perspective.

Sign languages can depict a physical action incorporating one or more arguments (e.g. object and/or instrument) or the way the action is performed. The use of depicting strategies in signed predicates is based on a cognitive mapping mechanism that blends formal properties of the signs and the representation of a certain event (Liddell 2003, Erlenkamp 2009). For this reason, addressing the iconic strategies underlying signs could provide us new insight on the cognitive background of meaning construction in sign languages. A central question among different tradition of studies (studies on symbol development, communicative gestures and sign language) is if during gestures or signs execution the body/hands represent real actions in the physical world taking a character viewpoint (i.e., how an action is performed by the agent with the entire body or how an object is held/used only by the hand) or represent other elements from an observer viewpoint (e.g., the object itself or its size and shape). The representational strategies for depicting events make visible different types of embodied practices and suggest a shared cognitive basis recruited by both gestural systems and language. The present study aims to address the use of representational strategies in Italian Sign Language (LIS) in actions depicting, with a special focus on the comparison between adults and children. This study will present data collected from 10 deaf signing adults and 24 deaf signing children divided in an older group (13; range 8 - 11 years) and a younger group (11; range 4 – 7 years). 27 different videos (extracted from the IMAGACT Database) referring to specific action types have been shown to participants that were asked to describe in LIS the action performed in each video clip. The different symbolic representational strategies used by participants have been coded according to the following labels: own body, hand as object, hand as hand, size and shape and double strategies (e.g. participants use two out of the four strategies to describe the action). The results indicated that all strategies have been found except for size and shape (Figure1). The differences between the three groups were investigated with non-parametric statistics (Mann-Whitney U test). With respect to both groups of children, adults used hand as object strategy significantly more frequently (z=-2,610; p<.01 and z=-3,570; p<.001 for younger and older children, respectively), and hand as hand strategy less frequently (z=-2,078; p=.04, and z=-2,486; p=.01 for younger and older children, respectively). The significant difference in the use of hand as object could be caused by a different degree of cognitive and linguistic complexity comparing to hand as hand (Taub 2001). In the latter case children replicate a motor action of their repertoire handling an imagined object while in the use of hand as object strategy their hand has to match a mental imagery of the object to be represented. Our results suggest a possible developmental trajectory from own body and hand as hand toward hand as object strategy.