[Recall of positive and negative life events. Studies of mood-inducing effect and production of texts].

Studies on the influence of affective states on cognitive processes have used different techniques of experimentally inducing the subjects' mood. One of these techniques, the "autobiographical recollection methodology" is analyzed in the present paper. The experimental studies are concerned with two main questions: first, the reliability, stability and potential reactivity of mood effects produced by this method as well as possible mechanisms underlying these effects; second, possible differences in the descriptions of positive versus negative life events are analyzed. In four studies with altogether N = 344 subjects, the participants were asked to remember and vividly write down an important happy or sad event from their lives. These descriptions were content-analyzed and their effects on the subjects' mood were studied. The results show that the autobiographical recollection methodology is in all four studies an effective mood induction technique lasting 15 minutes. After this time, the subjects' mood comes back to its pretest state. If an adequate cover story is used, there are no signs of reactivity effects of this method. With respect to the underlying mechanisms, the data show that the vividness and specificity of the description were positively related to the respective mood effects. Additionally, the description of negative events led to stronger mood effects when they were uncontrollable. All other variables analyzed (for example, number of words written, time needed, degree of analytical reasoning, degree of expressed emotionality) were unrelated to the mood changes. It is concluded that the effect of the autobiographical recollection methodology is dependent mainly on the event valence category and more or less unrelated to quantitative variables of the event description. With respect to the descriptions of positive versus negative life events, the data show that descriptions of sad events were longer, took more time, were more analytical, and contained more causal attributions than descriptions of positive events. These differences are interpreted as demonstrations of a positivity negativity asymmetry in the processing and storage of affective material.