Sign languages, in addition to using the hands, also use positions and movements of other articulators: the body, the head, the mouth, the eyebrows, the eyes and the eyelids, to convey lexical, grammatical, and prosodic information. This linguistic use of the nonmanual articulators is known as nonmanuals. Contrary to current assumptions in the field of sign linguistics, this project proposes the hypothesis that all sign languages use the same basic universal building blocks (nonmanual movements) but that each language is different in how it combines these building blocks both sequentially and simultaneously; languages also differ in the regularity, frequency, and the alignment properties of the nonmanuals. In order to test this hypothesis, we use Computer Vision to measure nonmanuals and advanced statistical techniques to analyze the formal properties of nonmanuals and compare them across contexts and languages. Using these techniques, we analyze naturalistic corpus data (recordings of natural conversations) in several sign languages, and focus on a variety of nonmanuals, such as head shakes used to express negation, head movements marking questions, and eye blinks marking sentence boundaries. We want to find out the extent of variation between the languages in how nonmanuals are used, and the universal patterns undelrying this variation.