WHAT HAPPENS TO HEART RATE DURING THE VIEWING OF LONG LASTING PLEASANT STIMULI?

Previous studies have shown larger heart rate deceleration during the viewing of unpleasant pictures compared to neutral and pleasant stimuli. More recently it has also been shown that high arousing pleasant pictures determine greater heart rate deceleration than neutral pictures. Less is known on heart rate changes during longer lasting pleasant stimuli. Particularly few studies have compared heart rate changes during high arousing pleasant and unpleasant film clips. The present study investigated the effects of high arousing pleasant (erotic film) and unpleasant (surgery film) film clips (120 sec) on heart rate, respiratory sinus arrhythmia (RSA), skin conductance level and corrugator EMG activity. As expected, arousal ratings of the pleasant and the unpleasant film clips did not differ from one another and were evaluated as more arousing compared to the neutral film. Results indicated a greater heart rate deceleration to the surgery and the erotic film clips compared to the neutral film. Particularly no differences were found between the two emotional films during the first 60 seconds fromthe onset of the stimuli, while during the last 60 seconds a greater deceleration for the surgery film compared to the erotic film was observed. No differences were found among the three films in RSA. A higher skin conductance level was found for the arousing film clips compared to the neutral. These results suggest that high arousing pleasant and unpleasant stimuli elicit a different pattern of heart rate changes across time.