Effects of differentially modeled stimuli on vicarious autonomic arousal

The present study examined effects of variations in modeled pain cues on level of vicarious arousal, using heart rate and blood-volume amplitude as psychophysiological measures. Students were assigned randomly to one of four groups in which they either (a) underwent directly the cold-pressor test, (b) observed a model exposed to the cold-pressor test and expressing pain by facial and bodily movements, (c) heard only the modeled verbal expressions of pain, or (4) observed the model express neither verbal expressions nor physical movements while undergoing the painful stimulation. The results show aversive stimulation increases heart rate whereas vicarious aversive stimulation produces reductions in heart rate. The deceleration of heart rate was not found in response to all three forms of modeling. Both direct and vicarious aversive stimulation produced decreases in the amplitude of vasomotor responses. The size of the decrement between direct stimulation and the minimal modeling condition of vicarious arousal showed significant differences, but differences between direct stimulation and the maximal modeling condition were not significant. The vasoconstriction was found in response to two forms of modeling.