|Abstract||Scientists have long been searching for physiological measures to detect and distinguish human responses to certain stimuli (e.g. emotion) in order to better understand emotional and cognitive processes. We investigated psychophysiological effects of different stressors (physical, emotional, cognitive) on electrodermal and physical activity of 14 to 15 year old adolescents in a laboratory study. Single and multiple stressors were applied using emotionally validated film clips, mental arithmetic tasks and treadmill walking following a standardized protocol. Subjective perception of stress and emotional state was recorded via questionnaires.
Physical activity levels increased with all stressors compared to resting conditions. Combining cognitive and emotional stressors was accompanied by higher physical activity than the single stressors. Likewise, all stimuli increased skin conductance levels (SCL). Combining physical and emotional stressors had an additional effect on SCL compared to single physical or emotional stressors, respectively. Skin conductance responses (SCR) were amplified during physical and cognitive tasks, but were not affected by emotional stressors. Impact of emotional valence: Emotionally positive versus negative stimuli were followed by similar physiological changes. Sex differences: With negative emotion, male participants showed higher activity levels compared to females, while female participants scored higher in subjectively perceived stress levels.
Few correlations between subjective and physiological measures might indicate sources of bias in questionnaire completion, e.g. social desirability bias or demand characteristics. Our results do not support the controversial theory of specific physiological reactions to positive versus negative emotional stimuli, but outline SCL to respond most stably to emotional stressors, whereas cognitive tasks were accompanied by a remarkable motor reaction that might be of functional relevance.||dc.description.abstract