It's in her hands : a case study of the emergence of phonology in American Sign Language

A case study of American Sign Language (ASL) acquisition revealed an emerging phonological system influenced by biological, cognitive, and linguistic factors. A hearing child (SJ), acquiring ASL from her Deaf parents, was videotaped over seven sessions between the ages of 1:0 and 2:1. Of the 1,699 manual behaviors observed, 804 were lexical items, or signs. All signs were phonetically coded. Detailed analyses were undertaken to discover acquisition patterns for the three major parameters of ASL signs (handshape, hand location and movement).Overall, SJ's signs were well-formed and adhered to ASL phonological constraints. Location primes were produced accurately, due to SJ's knowledge of the structure of her body. Errors occurred with body parts that were not perceptually salient. Movement parameters were not mastered by SJ during the period of study; no systematic set of substitutions was observed. Handshapes were produced with low accuracy. SJ relied on a small set of maximally contrastive handshapes (i.e., (5,1,A)). These handshapes represent the convergence of ease of production, distribution in the target language phonology, and perceptual salience. SJ used three processes to fit target handshapes to her emerging phonological system: spreading of selected fingers, changing of selected fingers from a marked to an unmarked set, and changing to an open position. These processes reflect anatomical and perceptual preferences as well as linguistic influences.SJ's sign production showed a small improvement in accuracy and a marked reduction in variability between the ages of 1:0 AND 2:1. Visual feedback did not affect the sign accuracy. A passive hand was more likely to be added to one-handed signs produced outside the visual field, possibly increasing tactile feedback. Path movement and horizontal-place primes were more accurate when tactile feedback was present. There was no evidence that SJ used lexical selection or imitation as strategies for phonological acquisition.Finally, many of the same factors that influence phonological acquisition in speech guided SJ's acquisition of handshape primes. Her acquisition of location primes, by contrast, did not resemble processes observed in phonological acquisition in speech