Neural and Cognitive Mechanisms of Trait Mindfulness and Their Relationships to Negatively-Valenced Emotional Reactivity

Mindfulness, an attentive non-judgmental awareness and focus on present moment experiences (Kabat-Zinn, 1994), can be used to refer to a particular type of meditation practice, a state achieved during meditation practice (alternately referred to here as a mindful state, or states of mindfulness), or an enduring and stable personality trait. While mindfulness is often viewed as a type of skill one can develop and cultivate during meditation practice, untrained individuals can vary in trait mindfulness. Trait mindfulness refers to one’s predisposition toward presentmoment attention and awareness in everyday life (Baer et al., 2006) and can change with experience and practice (e.g., Nyklicek et al., 2013; Shapiro et al., 2011). One's predisposition to be mindful in everyday life can be increased by evoking mindful states consistently (e.g., Davidson, 2010), and psychological health benefits are thought to result from increased trait mindfulness due to mindfulness meditation practice (Kiken et al., 2015). High trait mindfulness is associated with an increased ability to release negative thoughts (e.g., Frewen et al., 2008) and more effective and flexible emotion regulation (e.g., Roemer et al., 2015). While improved emotion regulation is generally associated with higher levels of trait mindfulness, research has been inconclusive regarding the relationship between mindfulness and emotional reactivity in the face of a negatively-valenced stressor, especially in non-meditators. The overarching purpose of the studies presented here is to ascertain the behavioral and brain bases of these emotion-mood relationships across 3 separate studies. In the first two studies, I examined the relationships between trait mindfulness and negatively-valenced emotional reactivity following a negative mood induction in non-meditators (Himes et al., 2021). The underlying mechanisms of this emotional self-regulation and flexibility cannot be understood by behavioral examination alone, and neuroimaging literature reveals that there are structural and functional brain differences between meditators and non-meditators in regions associated with emotional and self-regulatory processing. It remains unclear whether these differences are solely due to training effects brought on by meditation practices or to trait effects that might be present in non-meditators based on their intrinsic level of mindfulness. By examining functional and structural brain differences in individuals with varying levels of trait mindfulness, a greater understanding of how trait mindfulness impacts emotion processing, and its brain bases, can be gained. To address this question, I examined whether, in a sample of non-meditators, individual differences in trait mindfulness are associated with structural and functional differences in brain regions associated with emotional, self-referential, and self-regulatory processing.