One of the richest veins in temporal-perception research is on the effect of emotion on cognition, and Droit-Volet has conducted a number of compelling studies that explore the relationship. In a recent series of experiments, her subjects viewed a series of images of faces, each of which was neutral or expressed a basic emotion, such as happiness or anger. Each image lasted onscreen for anywhere from 0.4 seconds to 1.6 seconds, and the viewer was asked to say whether the image lasted for a “short” or a “long” time—that is, closer to one of the two standard durations they’d been trained beforehand to recognize. Consistently, viewers reported that happy faces seemed to last longer than neutral ones, and both angry and fearful faces seemed to last longer still.
(via http://nautil.us/issue/45/power/time-is-contagious)