Organizational Neuroscience with Applications to Stress Management

Abstract

This thesis was on organizational neuroscience with applications to stress management. Section 1 developed an organizational neuroscience model of occupational stress that integrated the health impairment process of the job-demands resources model of occupational stress with the (biologically-grounded) allostatic load model of stress. In doing so, this section developed a series of propositions that integrated each model through a job demands-allostatic load pathway. Resilience training was discussed as a potential moderator of this pathway with a focus on mindfulness meditation, physical activity, and multi-modal interventions that comprise each of these practices completed concurrently.

In Section 2 of this thesis, specific methodological, interpretational, and philosophical concerns that arise when adopting an organizational neuroscience approach to research were discussed across two critical essays. This included a focus on the appropriateness of statistical analyses in organizational neuroscience, the implications of the completeness and transparency of reporting research findings, and what kind of causal inferences can be drawn about organizationally-relevant behavior using neuroscience data. These essays served as the statistical and philosophical framework through which the empirical studies conducted in Section 3 were conducted and interpreted.

Finally, Section 3 of this thesis was a conceptual evaluation of the resilience training propositions of the theoretical model developed in Section 1. It was a conceptual evaluation in that the sample was one of convenience rather than a working population, specifically. This included three studies conducted within a pilot and feasibility trial that comprised formal mindfulness psychoeducation and aerobic endurance exercise training, completed concurrently. It has been theorized that interventions of this kind exert salutary effects on mental health outcomes through neurobiological mechanisms. To assess this, this intervention was evaluated at multiple levels of analysis to build a comprehensive understanding of its effect on the mind, brain, and physiology.

The primary aim of Study I was to investigate the effect of this intervention on self-reported chronic psychosocial stress, and potential mechanisms involving dispositional mindfulness, adaptive and maladaptive emotion regulation strategies, and maximal and submaximal cardiorespiratory fitness. Notably, participation in this intervention was associated with a reduction in chronic psychosocial stress, and an improvement in wellbeing that is considered clinically meaningful with respect to the scale. The primary aim of Study II was to investigate whether the effects of this intervention on mental health outcomes may occur through neural mechanisms, as predicted by theoretical models. This involved a longitudinal voxel-based morphometry study with a focus on gray matter concentration within the hippocampus. This study provided preliminary evidence that this intervention was associated with increases in gray matter concentration within the hippocampus, as well as within regions associated with stress regulation, memory, and sensorimotor processes. The primary aim of Study III was to investigate whether the aerobic endurance training component of this intervention was associated with exercise-induced adaptations to stress-responsive systems. This is of note because these adaptations have been posited to spill over to heterotypic stressors like psychosocial stress, and confer resilience to adversity more broadly. This was evaluated through measuring the cortisol response to a submaximal steady state exercise bout before and after the training period. In this study it was identified that training was associated with an attenuation of cortisol responses, which was indicative of physiological adaptations that enable submaximal exercise workloads to be conducted with greater efficiency and less strain. Limitations and implications for future research were also discussed.