Our linguistically annotated American Sign Language (ASL) corpora have formed a basis for research to automate detection by
computer of essential linguistic information conveyed through facial expressions and head movements. We have tracked head position
and facial deformations, and used computational learning to discern specific grammatical markings. Our ability to detect, identify, and
temporally localize the occurrence of such markings in ASL videos has recently been improved by incorporation of (1) new techniques
for deformable model-based 3D tracking of head position and facial expressions, which provide significantly better tracking accuracy
and recover quickly from temporary loss of track due to occlusion; and (2) a computational learning approach incorporating 2-level
Conditional Random Fields (CRFs), suited to the multi-scale spatio-temporal characteristics of the data, which analyses not only
low-level appearance characteristics, but also the patterns that enable identification of significant gestural components, such as
periodic head movements and raised or lowered eyebrows. Here we summarize our linguistically motivated computational approach
and the results for detection and recognition of nonmanual grammatical markings; demonstrate our data visualizations, and discuss the
relevance for linguistic research; and describe work underway to enable such visualizations to be produced over large corpora and
shared publicly on the Web