Cyclic Movement Primitives Underlying Two-Handed Alternating Signs In Signed Languages

Abstract

In speech, biomechanical constraints shape phonetics-phonology. For example, English /r/ variants are selected based on minimizing biomechanical effort [1] and a single motor action in the tongue may govern multiple speech events to improve movement efficiency [2]. We propose that signed languages are similarly constrained by biomechanics. Specifically, the present paper considers the hypothesis that otherwise unexplained universal aspects of sign languages can be understood as resulting from a preference for repeated alternating arm movements triggered by vestigial locomotor CPGs developed in human ancestors for quadrupedal locomotion.