Categorical Perception for Emotional Faces

Abstract

Categorical perception (CP) refers to how similar things look different depending on whether they are classified as the same category. Many studies demonstrate that adult humans show CP for human emotional faces. It is widely debated whether the effect can be accounted for solely by perceptual differences (structural differences among emotional faces) or whether additional perceiver-based conceptual knowledge is required. In this review, I discuss the phenomenon of CP and key studies showing CP for emotional faces. I then discuss a new model of emotion which highlights how perceptual and conceptual knowledge interact to explain how people see discrete emotions in others' faces. In doing so, I discuss how language (emotion words included in the paradigm) contribute to CP.

Keywords: categorical perception; emotional faces; language.

Figure 1

Morphs from anger to fear created at 10% intervals. Participants who perceive these faces in a categorical fashion identify morphs in two discrete groups with consistency. Participants typically identify morphs 1–5 as angry and morphs 6–10 as fearful (given the two emotion words). Given such identification, the categorical boundary would be between morphs 5 and 6.

Figure 2

Example of an AB-X discrimination trial. Participants see morph A, then morph B, then are asked to indicate whether morph X is either A or B. Here X is B.