Psychophysiological Indices of Arousal in Mindfulness Meditation

Mindfulness meditation is widely recognised for its health benefits, yet the psychophysiological mechanisms underlying these benefits remain only partially understood. This thesis aimed to clarify these mechanisms by comprehensively examining both immediate (state) and long-term (trait) effects of mindfulness meditation, with a focus on neural activity measured by electroencephalography (EEG) and sympathetic arousal assessed via skin conductance level (SCL). Five empirical studies systematically investigated arousal and attention mechanisms in novice meditators, utilising both traditional EEG analyses and innovative data-driven methodologies.Study 1 investigated state and trait changes in alpha amplitude and SCL, comparing mindfulness meditation to an active control condition (classical music listening), an approach that, while uncommon in mindfulness research, is crucial for isolating specific meditation-related effects. Results showed reductions in alpha amplitude independent of sympathetic arousal, suggesting enhanced attention rather than altered arousal during mindfulness meditation. Study 2 extended this investigation across all traditional EEG frequency bands, revealing significant trait-related changes in global alpha and beta amplitude after six weeks of daily practice, along with emerging theta changes linked to attention and awareness.Due to disruptions caused by COVID-19, the subsequent studies in this thesis shifted focus to the immediate (state) effects of mindfulness meditation, with particular emphasis on breath regulation. Study 3 compared paced breathing with mindfulness meditation, revealing widespread EEG changes across all frequency bands and contrasting effects on sympathetic arousal. Building on these findings, Study 4 combined paced breathing with mindfulness meditation and compared it to mindfulness meditation with spontaneous breathing. This comparison demonstrated that deliberate breath control during meditation produces interacting effects on global theta, alpha, and beta amplitude, along with SCL.Study 5 employed a data-driven EEG analysis method and directly compared it with the traditional approach using fixed frequency bands, as in prior studies. This innovative method revealed several novel findings, most notably a complex delta-theta-alpha component that increased significantly during meditation, reflecting a meaningful neural change that traditional analyses cannot capture.Collectively, these findings advance our understanding of the psychophysiological mechanisms underlying mindfulness meditation. While this thesis thoroughly examined the role of arousal, the observed neural and autonomic changes were not primarily driven by sympathetic activity. Instead, they appear to reflect attentional processes that are engaged during mindfulness meditation. These results reinforce the view that mindfulness meditation fosters a state of relaxed alertness, characterised by sustained attention and heightened awareness. They align with theoretical models that conceptualise mindfulness as an active, dynamic cognitive process and help explain its broad applications in health, education, and clinical practice. Future research should continue to investigate how attention, arousal, and breathing each contribute to the cognitive and physiological benefits of mindfulness meditation.