The Effect of a Mismatched Audiovisual Stimulus on Heart Rate, Respiration Rate, Skin Conductance, and Beta Waves

Abstract

Previous research has shown that sensory stimuli can induce a stress response. This response occurs as a result of a sympathetic response involving the hormones epinephrine, norepinephrine, and cortisol. Sensory stimuli initiate this response through immediate preconscious processing and longer-term conscious processing in the central nervous system. The stress response results in increased heart rate, respiration rate, skin conductance, and beta wave frequency among other physiological measures. Overactivation of the stress response has been found to cause stress-related diseases. The purpose of this study was to assess if a novel audiovisual (AV) stimulus synthesizing previous research provoked a greater stress response than traditional audiovisual stimuli. This study utilizes a novel mismatched AV stimulus that paired emotionally connotated images with oppositely connotated sounds.The traditional matched AV stimulus paired emotionally connotated images with correspondingly connotated sounds. 25 subjects between the ages of 20 and 22 were treated with a three minute video from one of the two conditions. Their heart rate, respiration rate, skin conductance, and beta wave frequency were recorded. The mismatched AV stimulus caused a significantly greater increase in heart rate, skin conductance, and beta wave frequency compared to the matched AV stimulus. The increase in respiration rate was not found to be significant. Overall, the research findings offer support that a mismatched AV stimulus elicits a greater stress response than a traditional, matched AV stimulus. These findings have future implications in neurological disorders and the optimization of stress reduction therapies.