Abstract
Heart rate variability (HRV) is a commonly referenced indicator of physiological stress.
This thesis undertook a detailed analysis of perceived stress and its connection with HRV
in both real-world and laboratory conditions.
This thesis presented eight chapters including a literature review, five empirical studies,
and one overall discussion. The literature review provided a thorough exploration
of stress research, examining the association between stress and HRV in both lab and
real-world settings. Therefore, the multi-method thesis seeks to bridge the gap between
laboratory and field studies by thoroughly examining the association between stress and
HRV from various angles. Chapters 3 and 4 investigated the effects of perceived stress on
HRV in real-world scenarios, each offering a unique lens. Chapter 3 analysed HRV
fluctuations at various times of the day, while Chapter 4 utilised daily questionnaires to identify
moments of heightened perceived stress. Together, they enriched our understanding of
HRV’s dynamic with stress, emphasising the importance of HRV timing and its patterns
relative to perceived stress state. Transitioning from field to lab, Chapter 5 introduced
an innovative, budget-friendly stressor. While not universally effective, it highlighted the
disparity between perceived and physiological stress. Chapter 6 compared the findings of
Chapters 4 and 5, elucidating the complexities of HRV as a stress marker across different
research environments. Chapter 7 ventured into a qualitative exploration, dissecting
the potential causes behind the mismatch between perceived and physiological stress. It
revealed three main themes, suggesting coping strategies that participants might have
employed, potentially mitigating their physiological stress responses in the controlled lab
setting.
In summary, the thesis not only supported the multifaceted nature of stress and its
physiological manifestations but also underscored the importance of contextualising HRV
measures within varying settings and scenarios.