Influence of facial expressions on the classical conditioning of fear

Previous research has demonstrated that particular facial expressions more readily acquire excitatory strength when paired with a congruent unconditioned stimulus than when paired with an incongruent outcome. The present study with a total of 36 undergraduates extends these findings on the excitatory inhibitory role of facial expressions by demonstrating that particular facial expressions (fear and happy), when paired with a neutral cue (tone), can influence conditioning to the neutral conditioned stimulus (CS). Ss who had a fear expression paired with the neutral CS responded more to the fear expression than to the neutral CS, whereas Ss who had a happy expression paired with the neutral CS responded more to the neutral cue than to the happy expression. These findings strongly support predictions from "overshadowing" or "blocking" models of classical conditioning. (12 ref)