Demand appraisals

According to the MBM (Gendolla, 2000), the informational mood impact extends to task-related appraisals of difficulty, ability, success anticipation, attributed importance of accomplishing the task, and so on. These demand appraisals during task performance are supposed to mediate mood effects on

effort mobilization – i.e., cardiovascular response (Gendolla & Krüsken, 2002c). Only Study 2, with conditions of different task difficulty standards, assessed two of these variables: task difficulty and attributed importance. A successful manipulation of task difficulty was evident by the main effect on this variable: participants evaluated the difficult task as more difficult than the easy task. However the data did not indicate mood congruency effects on participants’ ratings of task difficulty, as would be expected according to the MBM. This can be due to the moment of the evaluation of task difficulty. The MBM assumes mood effects on subjectively experienced demand during task performance. Therefore, the critical moment for assessing the demand appraisal should be during the task; but in our experiment, the evaluations were made before the task, a constriction due to pragmatic reasons. If the demand appraisals were asked during the task, performance interruptions would be needed, which more probably would lead to disengagement and also disturb the accuracy of physiological measures.

However, the cue manipulation present in Study 2 directly manipulated the effective diagnostic value of participants’ moods during task performance. Since the pattern of effort-related cardiovascular reactivity was moderated in the predicted direction, we can conclude that the manipulation was efficient and that the observed effects were due to an informational mood impact, even though the self-report measures did not accurately reflect this influence. The limitations of self-self-reported measures will be further discussed in section 3.1.2. and some restrictions were already mentioned in the Theoretical part (section 4.9.).

The absence of significant results in attributed importance of success means that, as intended, there were no differences between the conditions in terms of potential motivation. Hence, we can deduce that the conditions were seen as similar in terms of maximally justified effort to achieve the task.

1.3. Systolic blood pressure reactivity

SBP response during the cognitive tasks completely supported our theoretical predictions for the present four experimental studies. Most importantly, there was no reactivity during the mood induction period or in a context that did not explicitly demand effort (e.g., Study 1), which corroborates with the postulate that moods per se are not motivational states. This replicates findings in studies from our lab (see Gendolla & Brinkmann, 2005, for a review). However when facing a context that explicitly called for effort, mood had an informational impact which systematically mediated resource mobilization. SBP reactivity responded to the informational mood impact with the predicted pattern for each of the studies. More precisely, in Study 1, in an intentional memorizing condition, stronger systolic

reactivity was observed for participants in a negative mood. When no explicit instruction for memorizing was given (incidental memorizing condition), the mobilization of effort was modest. Following the logic of a resources conservation principle, and more concretely the MBM basic assumptions, this effect was anticipated since it was considered that resource mobilization would only occur in a context that explicitly calls for effort – as in our intentional memorizing condition. In studies 3 and 4, it was clear to all participants that they had a task to perform and that effort adjustments were needed according to two effort-rules: the enough-rule and the enjoy-rule. Higher values of SBP were observed in a negative mood if the effort-related judgment was centered on duty or if nothing was said concerning effort mobilization (as in other studies on the MBM), following subjective demand appraisals in a mood congruent manner. However, participants showed stronger reactivity in a positive mood if the effort-related judgment focused on the task’s pleasantness/enjoyment. In study 2, and contrary to the above mentioned, participants were presented with fixed performance standards: an easy or difficult task.

When the informational mood impact was considered (no-cue conditions), there was the expected interaction of mood and task performance standards effects: stronger reactivity while in a negative mood for an easy task and while in a positive mood for a difficult task. Since mood was included in the effort-related demand appraisal, participants in a negative mood evaluated the easy task as more demanding and the difficult task as already too demanding. As result, in the easy task/negative mood condition, SBP reactivity was stronger, while it was weaker in the difficult task/negative mood cell. The mood effects on cardiovascular reactivity were substantially reduced when participants were informed of the mood induction. In these conditions, systolic reactivity was determined by objective task difficulty: higher scores for the difficult condition than for the easy one, regardless of the mood state that was previously induced.

The clear correspondence between our predictions and SBP activity is not surprising due to the characteristics that make SBP particularly sensible for effort mobilization. As described in more detail in chapter 4., SBP reactivity represents an index of SNS activity, which is mediated by beta-adrenergic receptors (see Brownley et al., 2000; Levick, 2003; Papillo & Shapiro, 1990). SBP is mainly influenced by myocardial contractility and TPR. Although TPR is not systematically linked to the activation of the SNS, myocardial contractility is determined by sympathetic discharge to the heart. Sympathetic discharge to the heart is in turn considered to correspond to experienced task demand in active coping (Obrist, 1981). Hence, its systematic link to sympathetic mediated contractility force of the heart muscle turns SBP reactivity into a reliable indicator of effort mobilization, and thus into a reliable indicator of the intensity of motivation (see Brehm & Self, 1989; Wright, 1996).