Human psychophysiological and self-rated emotional responses to geranium visual stimuli during recovery from stress

This research analyzed psychophysiological and self-rated emotional responses of college students to geranium visual stimuli during recovery from an induced stress. Seventy-five female and 75 male college students were randomly assigned to one of three visual treatments: red-flowering geraniums, non-flowering geraniums, or no plants. Following a 5-minute baseline period, each student viewed a 10-minute film of a stressful human situation, then was exposed to an assigned treatment for a 5-minute recovery period. Psychophysiological measurements were taken of brainwave activities (alpha: 8–12 Hz, beta: 21–27 Hz), electrodermal activities (EDA), and finger skin temperatures. Self-rated emotional states were assessed using the Zuckerman Inventory of Personal Reactions. Tests for differences between treatments were done using the analysis of covariance on the psychophysiological data and the Kruskal Wallis test on the self-rated data.; High-stress induced females had greater recovery (decrease) in beta brainwave activity and EDA when exposed to red-flowering geraniums as compared to non-flowering geraniums and to no plants. The stress-recovery effects of exposures to red-flowering geraniums involved immediate and rapid positive reactions. Lower alpha brainwave activity of high-stress induced females exposed to red-flowering geraniums suggested that red-flowering geraniums tended to hold non-stressful ‘intake attention’ resulting in positive distraction from stress. Non-stress induced females had greater arousal (increase) in beta brainwave activity when exposed to red-flowering geraniums as compared to non-flowering geraniums and to no plants. The increased beta brainwave activity of non-stress induced females exposed to red-flowering geraniums was associated with positive emotional arousal. Self-ratings by females indicated greater positive affects and attentiveness when they were exposed to red-flowering geraniums as compared to non-flowering geraniums and to no plants. Both psychophysiological and self-rated emotional responses of males were not significantly influenced by any treatments.