ABSTRACT
The ability to visually encode changes in facial musculature that reflect emotional state is essential for effective social communication. Models of face processing have proposed either that the perception of facial expression is dependent on a continuous neural representation of gradations in expression along critical dimensions or that it is based primarily on the assignment of expressions to discrete emotion categories. The occipital face area (OFA) is thought to be involved in the early perception of facial features and has a postulated projection to the posterior superior temporal sulcus (pSTS). The connection between the OFA and pSTS is thought to be important in processing dynamic changes in the face, such as changes in expression and gaze, which are important for social interactions. Brain regions that hold a more categorical perception of expression should be sensitive to between-expression changes in expression, but not within-expression changes. However, regions with a continuous representation should be equally sensitive to both between- and within-expression changes.
