A Case Study of a Deaf Autistic Adolescent's Affective and Linguistic Expressions.

Facial expressions and body language play crucial roles in communication by conveying emotional and contextual information. In signed languages, facial expressions also serve linguistic functions. While previous research on autistic individuals' facial expressions has focused primarily on affective expressions in hearing people, studying deaf autistic individuals offers insight into how autism affects linguistic and affective facial expressions. This case study examines the nonmanual expressions of "Brent," a Deaf autistic adolescent natively exposed to American Sign Language (ASL). Five video recordings (four monologues and one conversation, totaling 35 m) were coded for nonmanual expressions, including affective facial expressions, question marking, negation, and other functions. Across 590 coded utterances, Brent showed absent or reduced facial expressions for both linguistic and affective purposes. However, he frequently used alternative communicative strategies, including additional manual signs, sign modification, and body enactment. Use of body movement to convey negation, affirmation, or emphasis was observed but inconsistently applied. These findings expand the current understanding of how autistic individuals use facial expressions by including linguistic functions in a signed language and support a broader view of autistic communication that embraces diverse and effective languaging strategies beyond neurotypical norms.