STANDARDIZED MOOD INDUCTION WITH HAPPY AND SAD FACIAL EXPRESSIONS

The feasibility of applying ecologically valid and socially relevant e motional stimuli in a standardized fashion to obtain reliable mood cha nges in healthy subjects was examined. The stimuli consisted of happy and sad facial expressions varying in intensity. Two mood-induction pr ocedures (happy and sad, each consisting of 40 slides) were administer ed to 24 young healthy subjects, who were instructed to look at each s lide (self-paced) and try to feel the happy or sad mood expressed by t he person in the picture. On an emotional self-rating scale, subjects rated themselves as relatively happier during the happy mood-induction condition and as relatively sadder during the sad mood-induction cond ition. Conversely, they reported that they were less happy during the sad mood-induction condition and less sad during the happy mood-induct ion condition. The effects were generalized to positive and negative a ffect as measured by the Positive and Negative Affect Scale. The intra individual variability in the effect was very small. In a retest study after 1 month, the mood-induction effects showed good stability over time. The results encourage the use of this mood-induction procedure a s a neurobehavioral probe in physiologic neuroimaging studies for inve stigating the neural substrates of emotional experience.