Abstract
Mindfulness-based interventions (MBIs) have been shown to be effective in reducing symptoms of chronic stress, but their therapeutic mechanisms are unclear. Monitor and acceptance theory (MAT) is a recent model of these mechanisms and suggests that MBIs train the cognitive function of attention monitoring and the emotion-regulation strategy of acceptance, which are thought to be impaired in chronically stressed people. The interaction between these improved abilities is theorised to drive chronic stress reduction. The main aim of the research presented in this thesis was to test MAT. To achieve this aim, three experimental studies and one literature review were conducted.
The first study (Chapter 4) was a cross-sectional investigation of the association between chronic stress, monitoring, and acceptance. Moreover, the study tested the hypothesis that the interaction between monitoring and acceptance skills is associated with chronic stress reduction, and that this association becomes stronger at higher levels of acceptance. Results from this study show that chronic stress is negatively associated with acceptance skills, but not with monitoring efficiency. Furthermore, the association between monitoring and chronic stress was not moderated by acceptance in the direction predicted by MAT.
The second study (Chapter 5) consists of a direct replication of the first study and in the exploration of the hypothesis that the cognitive function of working memory might constitute a better definition of monitoring compared to attention. To test this hypothesis, this study explored the association between working memory capacity and chronic stress, and the moderating effect of acceptance on the association between working memory and chronic stress. The results from this study replicated the findings of the first study but did not provide support for the hypothesis that working memory might provide an alternative to attention as a definition of monitoring.
The third study (Chapter 6) was a feasibility pilot study testing the hypotheses that mindfulness training improves monitor and acceptance skills, and that the interaction between these improved skills drives stress reduction. Results from this study show that the main study is feasible and that MBIs might partially improve monitoring and acceptance skills. However, there was no evidence that the interaction between changes in monitoring and acceptance is associated with chronic
stress reduction. These results, obtained from an intervention study, corroborate findings from the cross-sectional studies reported in Chapters 4 and 5.
The last study (Chapter 7) consists of a review of MAT’s foundational literature. Results from this work reveal that the literature cited in support of MAT might not provide a solid ground for the model, as contradictory evidence supports its tenets. It was concluded that future research should focus on providing a more robust definition of the components of MAT and test its hypotheses.
In summary, results from this thesis support MAT’s hypothesis that acceptance, but not monitoring, is a therapeutic mechanism of MBIs. However, given the preliminary nature of some of the research presented in this thesis (i.e., the pilot study presented in Chapter 6) and the limited available literature testing MAT, further work is warranted to test this model before potentially updating it according to the evidence.