Prosody in sign language
Prosody is defined as "the study of rhythmic structure, intonation, stress, and related attributes in conjunction with syntax in speech and signing".
In sign language, prosodic features include: duration of a sign, pause, eye aperture, facial expression, use of signing space, etc.[a demo in video coming soon]
A sociolinguistic researcher studied in search of sociolinguistic factors as to why Deaf people sign with a pinky extension and to determine whether it is a variation. An interesting finding was that:
"pinky extension tended to co-occur with prosodic features of emphatic stress. Specifically, it tended to occur (a) with lexemes used repeatedly within a discourse topic, (b) before pauses, and (c) with lexemes lengthened to almost twice their usual duration. This suggests that pinky extension is itself a prosodic feature of ASL that adds emphatic stress..." -- Linguistics of ASL (2005), p 465.
Dachkovsky, Svetlana; Sandler, Wendy. "Visual Inonation in the Prosody of a Sign Language." Language and Speech, 2009. Pp 287- http://sandlersignlab.haifa.ac.il/pdf/Visua_Intonation.pdf
Nicodemus, Brenda. "Prosodic Markers and Utterance Boundaries in American Sign Language." Gallaudet University Press. http://gupress.gallaudet.edu/excerpts/PMUB.html
Sandler, Wendy. "Prosody and Syntax in Sign Languages". 2010. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3250094/
Related topics: emphatic stress in sign language.