title: Affective learning increases sensitivity to graded emotional faces.
abstract: How does the affective significance of emotional faces affect perceptual decisions? We manipulated affective significance by pairing 100% fearful faces with aversive electrical stimulation and hypothesized that increasing the significance of a stimulus via its prior history would lead to enhanced processing. After fear conditioning, participants viewed graded emotional faces that ranged from neutral to fearful. Faces were shown either in a color that was previously paired with shock or a color not paired with shock during conditioning. Increases in the frequency of "fearful" responses for faces shown in the shock-paired color were most robust for faces at intermediate intensity levels (40-60% fearful). Psychometric fits to the data revealed significant increased sensitivity for shock-paired relative to unpaired faces. Thus, despite identical physical features for shock-paired and unpaired stimuli (aside from the color, which was counterbalanced), more frequent (and faster) "fearful" responses were made when participants viewed affectively significant stimuli.
authors.affiliation: Indiana University, Bloomington, IN 47405, USA.
authors.forename: Seung-Lark
authors.initials: SL
authors.lastname: Lim
authors.forename: Luiz
authors.initials: L
authors.lastname: Pessoa
mesh_terms: D000293:Adolescent; D000328:Adult; D000339:Affect; D003213:Conditioning, Psychological; D005145:Face; D005149:Facial Expression; D005239:Fear; D005260:Female; D005712:Galvanic Skin Response / Q000502:physiology; D006801:Humans; D007858:Learning; D008297:Male