Does age of language acquisition affect the relation between American Sign Language and mental rotation

Past research has shown a relation between knowledge of American Sign Language (ASL) and mental rotation. The goal of the current study was to examine factors related to American Sign Language use that contribute to mental rotation skills. In particular, the factors examined were age of acquisition of ASL, hearing status, gender, spatial language comprehension, spatial language production and amount of use of ASL. Many studies have examined the role of language on cognition, but few have examined which aspects of language knowledge (comprehension or production) contribute to those effects. Further, this study examines the role of age of acquisition of ASL on mental rotation. Participants were adults who had learned ASL at different ages across development. Participants completed a spatial language production task, spatial language comprehension task and a computerized-nonlinguistic mental rotation task that recorded participants' accuracy and reaction times.;Results showed that native male signers were significantly faster on mental rotation compared to other groups based on the slope of change across degrees of rotation. Further, male native signers were also slightly more likely to interpret spatial relations in the comprehension task by rotating the signer's description. There were no overall differences between the age of acquisition groups in mental rotation. Men and women did not differ overall in mental rotation nor did hearing and Deaf participants. These results indicate that age of acquisition of ASL after infancy does not affect mental rotation. Implications are discussed for age of acquisition effects on language-cognition relations, for the effects of practice on male native signers' speed of mental rotation, and implications for findings on the language tasks. Further research should examine the effects of age of acquisition of a first language on general speed of processing.