Modulation of Physiological Response to Affective Stimuli: A Tool for Psychological Processes Assessment

Conventional tools for the assessment of psychological processes rely on the use of self-report questionnaires and behavioral tasks, in spite of the existence of objective and more accurate physiological responses that could provide new insights into such processes. Accordingly, the aim of this study was to analyze the changes in different physiological responses to stimuli with different affective content, to obtain physiological indicators of the attentional, emotional and motivational processes. The responses of 40 participants were recorded while observing pleasant, neutral and unpleasant stimuli. Results show that the pleasant and unpleasant stimuli generate a greater galvanic skin response, which indicates a greater sympathetic activation and a greater orientation response, as well as a greater heart rate deceleration and greater prepulse inhibition, which suggests a greater attentional response. It was also found that unpleasant stimuli enhance the startle reflex and the pleasant stimuli inhibit it, making it a physiological marker of motivational response. There were no significant differences between men and women. Overall, the results support the use of these methodologies for the study of orientation/attention, emotion and motivation.