title: The use of aftereffects in the study of relationships among emotion categories.
abstract: The perception of visual aftereffects has been long recognized, and these aftereffects reveal a relationship between perceptual categories. Thus, emotional expression aftereffects can be used to map the categorical relationships among emotion percepts. One might expect a symmetric relationship among categories, but an evolutionary, functional perspective predicts an asymmetrical relationship. In a series of 7 experiments, the authors tested these predictions. Participants fixated on a facial expression, then briefly viewed a neutral expression, then reported the apparent facial expression of the 2nd image. Experiment 1 revealed that happy and sad are opposites of one another; each evokes the other as an aftereffect. The 2nd and 3rd experiments reveal that fixating on any negative emotions yields an aftereffect perceived as happy, whereas fixating on a happy face results in the perception of a sad aftereffect. This suggests an asymmetric relationship among categories. Experiments 4-7 explored the mechanism driving this effect. The evolutionary and functional explanations for the category asymmetry are discussed.
authors.affiliation: Department of Psychology, Neuroscience and Behaviour, McMaster University, Hamilton, ON, Canada. rutherm@mcmaster.ca
authors.forename: M D
authors.initials: MD
authors.lastname: Rutherford
authors.forename: Harnimrat Monica
authors.initials: HM
authors.lastname: Chattha
authors.forename: Kristen M
authors.initials: KM
authors.lastname: Krysko
mesh_terms: D000328:Adult; D000339:Affect; D019260:Expressed Emotion; D005260:Female; D006801:Humans; D008297:Male; D014796:Visual Perception