Fig. 2.

Experiment 2: Behavioral results from expression-classification experiment. Performance was determined for four morph continua: fear to happy (A), happy to disgust (B), disgust to fear (C), and disgust to sad (D). The x axis shows the four morph levels from the continua that were used in the experiment. The graph represents the proportion of participant’s responses that used the name given on the y axis, averaged across participants. A clear discontinuity is evident in the perception of emotion near the midpoint of the morphed continuum, which provides support for a categorical representation of facial expression. Images of faces are from ref. 47.