A multi-method approach to understanding pain experience using non-pharmacological interventions that target alpha brain activity

This thesis aimed to examine the relationship between pre-stimulus somatosensory alpha activity and pain experience. Four studies were included to assess: 1) if, and how pre-stimulus somatosensory alpha activity might affect pain experience; and 2) if the relationship between pre-stimulus somatosensory alpha activity and pain experience is influenced by uncertainty about pain intensity, fear of pain and pain catastrophising. Study 1 was designed to replicate the negative correlation between pre-stimulus somatosensory alpha activity and pain. Studies 2-4 each investigated the potential of a different intervention to reduce pain by increasing alpha: binaural beats, transcranial alternating current stimulation (tACS), and mindfulness meditation. Study 1 confirmed the correlation between pre-stimulus somatosensory alpha activity and pain experience, but it was the findings of Studies 3 and 4 that were crucial in advancing the understanding of the relationship between somatosensory alpha activity and pain. They provided novel findings suggesting that modulation of somatosensory alpha (to increase alpha) results in reduced pain experience, thus demonstrating that pre-stimulus somatosensory alpha activity and pain experience might be causally related. This thesis also provided evidence for an influence of uncertainty about pain intensity on the relationship between alpha activity and pain experience. Study 1 showed an influence of uncertainty on pre-stimulus somatosensory alpha activity. Moreover, the application of tACS (to increase alpha) only resulted in a significant reduction of pain experience when pain intensity was uncertain. Finally, Study 3 demonstrated a relationship between pain catastrophising and the reduction of pain by tACS, higher pain catastrophising was associated with a larger reduction of pain experience. Together, the studies of this thesis not only provided a first indication of a causal relationship between pre-stimulus somatosensory alpha activity and pain, but also initial evidence for the effectiveness of interventions targeting alpha activity in the management of pain.