ELECTRODERMAL AND SUBJECTIVE REACTIONS TO FEAR-RELEVANT STIMULI UNDERTHREAT OF SHOCK

Three experiments investigated normal subjects' reactions to pictures of fear-relevant stimuli (snakes, spiders, guns) and control stimuli ( e.g., flowers, rabbits) under threat of electric shock. First-interval electrodermal responses (FIRs) and shock expectancy ratings were reco rded. Experiment 1 demonstrated larger FIRs and expectancy ratings to fear-relevant stimuli, with and without threat of electric shock. In E xperiment 2, trait anxious subjects showed elevated expectancy ratings that were additive with the bias associated with fear-relevant stimul i. Experiment 3 demonstrated that reactions to fear-relevant stimuli w ere not an artefact of the expectancy rating task. There were no subst antial differences between biological and technological fear-relevant stimuli. Overall, the experiments confirm that fear-relevant stimuli e licit larger reactions in the absence of any specific manipulation, su ch as conditioning. The results are most consistent with cognitive mod els that emphasis learning rather than genetic factors, and that attri bute electrodermal reactions to elevations expectancy of aversive even ts.