Facial Expressions in Sign Language

Meaningful facial movements and configurations that serve grammatical, lexical, and affective functions in sign languages. In American Sign Language, facial expressions are not merely emotional indicators but carry essential linguistic information including marking questions (raised eyebrows for yes/no questions, furrowed brows for wh-questions), indicating topics, conveying adverbial information, and distinguishing between sentence types. Non-manual markers are a required component of ASL grammar, and their absence in sign language animations or generation systems significantly reduces the grammaticality and naturalness of the output.