Abstract
Introduction: There is a paucity of knowledge regarding the relationship between self-perceived interoceptive awareness and mindfulness, the cortical response to mindfulness-based interventions (MBIs). There is a further lack of information on the association between enhancement-based psychological factors and pain sensitivity profiles based on tolerance and analgesia markers.
Methods: A 2-armed randomized cross-sectional experimental pilot study of yogis which involved: (i) self-report outcomes of mindfulness, interoceptive awareness, healthy emotionality, and psychological wellbeing, (ii) cortical hemodynamic responses acquired during the sequentially delivery of 2 brief MBIs: standing yoga and seated body scan meditation, and (iii) experimentally evoked pressure pain threshold and tolerance pre- and post-MBI. Baseline self-report outcomes included: Five Facet Mindfulness Questionnaire – Short Form (FFMQ-SF), Multidimensional Assessment of Interoceptive Awareness (MAIA-2), Emotional Styles Questionnaire (ESQ), Scales of Psychological Well-Being (SPWB). Repeated pressure pain threshold and tolerance testing applied over the ventral thenar eminence of the nondominant hand pre- and post-MBI. Cortical hemodynamic responses (Oxygenated Hemoglobin, HbO) were acquired using functional near infrared spectroscopy (fNIRS). Pressure pain threshold and tolerance were acquired over the ventral thenar eminence using digital algometry.
Results: Interoceptive awareness (MAIA-2) was not correlated with psychological wellbeing (SPWB) but was positively correlated with healthy emotionality (ESQ) at a moderate to good level of magnitude (n=14, p-=value=.01, r=.66). Cortical activity across the 2 MBIs were not correlated with mindfulness (FFMQ-SF) or interoceptive awareness (MAIA-2). Pain threshold and tolerance were not associated with the acceptance in action or regulatory awareness clusters. Most yogis (n=10) experienced hyperalgesia immediately after participation in the MBIs (Mean change=419.84, SD ± 158.89), however, a subset of yogis (n=3) experienced hypoalgesia (Mean change=562.1, SD ± 129.42). Cortical activity was higher during the yoga practice compared to the body scan practice, as represented by β values of HbO levels of the same channels across participants (Ch 7 : n=10, p-value=.03, t 18 =-2.43; Ch 8 : n=10, p-value=.02, t 18 =-2.69).
Discussion: Interoceptive awareness was related to healthy emotionality, which contains the constituents of outlook, resilience, social intuition, self-awareness, sensitivity to context, and attention. Mindful awareness and interoceptive awareness were not related to hemodynamic responses derived during brief exposures to MBIs with the form of focus-awareness practice. Psychologically based ‘acceptance in action’ and ‘regulatory awareness’ clusters were not related to pain threshold or tolerance. Increased pain sensitivity was observed for most participants after exposure to the MBIs. Higher cortical activity was demonstrated in the movement-based yoga practice compared to the resting-based body scan practice.