A recent study by Zara Ambadar and Jeffrey F. Cohn of the University of Pittsburgh and Jonathan W. Schooler of the University of British Columbia, examined how motion affects people's judgment of subtle facial expressions. Two experiments demonstrated robust effects of motion in facilitating the perception of subtle facial expressions depicting six emotions: anger, disgust, fear, happiness, sadness, and surprise. For the initial experiment, participants viewed a series of subtle facial expressions, displayed by faces on a computer screen. While the second experiment was conducted in a format similar to the first, it added a new condition called "first-last mode," that contained only the first and last images of each sequence. The results of both studies confirmed that, overall, motion improves perception of facial expressions. "Given the absence of evidence for any of the alternative roles of motion considered in the current studies, it seems quite likely that the benefits of motion observed here stem from its ability to enhance individuals' perception of the way in which expressions have changed. The present findings thus suggest that motion's role in the detection of change ... is critical in mediating individuals' sensitivity to the communication of emotion."