Reliability of a measure of perception of autonomic responses to affective visual stimuli

Abstract

The purpose of this study was to examine the stability of a measure of participants' perception of autonomic responses to affective visual stimuli. Specifically this study was to determine the accuracy of participants' claims of emotional responses to affective visual stimuli. The affective visual stimuli were colored and black-and-white slides of ordinary objects, nude females, tragic scenes and restful scenes. A total of 20 subjects (12 females and 8 males) participated in the study. The subjects were volunteers from undergraduate educational psychology courses. On the first day of testing each participant was show 16 slides. The first 8 slides were designed as slide set A₁. The last 8 slides were designated as slide set B. Two weeks after the first session the participants returned to be shown slide set A₁ again which was designated as slide set A₂. The participants were instructed to operate a microswitch when they felt that they were responding emotionally to a particular slide. Each participant was being monitored by a Narco physiograoh while viewing the slides. The physiological variables being recorded were skin conductance, pulse volume and heart rate. Each of the physiological variables were transformed into z scores. Total activation values were calculated for each individual for each slide by adding z scores together. Threshold values were then calculated by taking the midpoint between the lowest total activation score of a claimed emotional response and the highest total activation value for a claim of no emotional response. Accuracy scores were a percent of the number of claimed responses above the threshold and the number of unclaimed responses below the threshold..