Mindfulness Meditation Training and Stress Reactivity: Behavioral Emotion Regulation Mechanisms

It has been proposed that dispositional mindfulness and mindfulness meditation training helps individuals become more attentive and aware of their inner processes and behavior. Yet we know very little about how mindfulness training reduces stress and the underlying mechanisms for these effects. The present study investigated several mechanisms of mindfulness and stress reduction by conducting secondary data analyses on 3-day mindfulness training study that included a Trier Social Stress Test (TSST) stress reactivity session after the 3-day training. This previous study showed that brief mindfulness meditation training reduced psychological stress reactivity while increasing salivary cortisol to the TSST. In the present study, we coded behavioral emotion regulation responses (via recorded videos) to the TSST. We tested two competing accounts for how dispositional mindfulness and mindfulness training affect stress reactivity, comparing emotional reactivity (showing less negative affect) and emotional expression (showing less emotional suppression). Results supported the emotion expression account, a significant training condition × dispositional mindfulness interaction on anger to the TSST was observed (β = 1.703, t(61) = 1.941, p = .057). Specifically, participants higher in dispositional mindfulness, who had also received mindfulness training had the greatest response to the TSST. We also tested for other behavioral accounts, including anxiety, confidence, and overall speech rating, but did not find any significant effects for mindfulness training, dispositional mindfulness, and their interaction. We conclude that mindfulness meditation training fosters greater emotion-focused coping efforts through emotional expression, which can help buffer stress. Mindfulness Training and Stress Reactivity 3 Mindfulness Meditation Training and Stress Reactivity: Behavioral Emotion Regulation Mechanisms In recent years, much research has focused on the topic of mindfulness (Hochman, 2013). Mindfulness is defined as enhanced attention and awareness to one’s present moment experience (Brown et al., 2007). The individual is aware (Grossman et al., 2011) of one’s own thoughts, emotions, and body sensations, and what is happening in one’s environment (Brown and Ryan, 2003). It has been proposed that mindfulness training helps individuals become more attentive and aware of their inner processes and behavior (Levitt et al., 2004) and fosters problem solving abilities allowing them to make better decisions (Ostafin and Kassman, 2012). This study aims to explore the mechanisms by which mindfulness meditation training reduces stress reactivity via changes in emotion regulation during the Trier Social Stress Test (TSST) (Kirschbaum et al., 1993). Mindfulness training has been associated with a broad range of stress reduction effects. There is growing evidence that practicing mindfulness meditation can improve stress related disease outcomes (Kabat-Zinn, 1982; Bedard e al., 2003; Hofmann et al., 2010; Evans et al., 2008; Creswell et al., 2009). Studies indicate that an 8-week Mindfulness-Based Stress Reduction (MBSR) intervention has a beneficial effect for reducing stress reactivity (Hoge et al., 2013; Shapiro et al., 2011), reducing blood pressure reactivity to stress (Nyklíček et al., 2013), and decreasing the amount of pain sensitivity (Zeidan et al., 2010). Even brief mindfulness training is associated with reduced stress and pain reactivity. Brief mindfulness programs, usually three days of mindfulness meditation training, also show a reduction in stress reactivity (Creswell 2014), pain intensity associated with orbitofrontal cortex activation (Zeidan et al., Mindfulness Training and Stress Reactivity 4 2011), and negative mood (Zeidan et al., 2010). Also, evidence provides that self-reported dispositional mindfulness reduces psychological and physical stress reactivity to social stressors (Arche & Craske, 2010; Brown et al., 2012; Barnes et al., 2007; Skinner et al., 2008). Despite this emerging evidence base, we know very little about how mindfulness training and dispositional mindfulness reduces stress. Thus, the present study investigated several purported mechanisms of mindfulness and stress reduction by conducting secondary data analyses on the Creswell et al. (2014) mindfulness training stress reactivity study. Specifically, this study had participants complete either three days of mindfulness meditation training (or an attention-matched control cognitive training). Immediately after the day 3 training, participants underwent the TSST. The results showed that brief mindfulness meditation training reduced psychological stress reactivity while increasing salivary cortisol reactivity to the TSST. The authors conclude that this may be due to the fact that mindfulness meditation training fosters greater active coping efforts, which reduces psychological stress appraisals but also increases cortisol reactivity (Creswell et al., 2014). Previous reviews of the mindfulness literature suggest that mindfulness meditation reduces emotional reactivity. Mindfulness decreases the intensity of negative affect threatening stimuli (Arch & Craske, 2006; Creswell et al., 2007; Shapiro et al., 1998; Brown & Ryan, 2003). This may be due to the buffering of emotional reactivity through emotion regulation. Hence, emotion regulation may be an underlying mechanism for mindfulness training effects (GieseDavis, et. al., 2012; Hayes & Feldman, 2006; Arch & Craske, 2006; Goldin & Gross, 2010; Chambers & Gullone, 2009). For example, Hayes and Feldman (2004) showed that mindfulness practice enhances emotional regulation by stabilizing emotions by either decreasing overengagement with internal experiences like rumination, anxiety, or obsessions or decreasing Mindfulness Training and Stress Reactivity 5 under-engagement like avoidance. Individuals high in mindfulness have also been shown to need less time to recover from negative emotional events (Kabat-Zinn, 1990). This facilitation of emotion regulation may be due to the fact that mindfulness fosters greater attention and acceptance of one’s present experience, thus facilitating greater attention to one’s feelings (Grossman & Van Dam, 2011; Brown & Ryan, 2003; Bishop et. al., 2004; Levit et. al., 2004). Although previous accounts suggest that mindfulness may reduce negative affective reactivity, an alternative emotion regulation pathway has been offered (Britton et al., 2012; Goldin & Gross, 2010; Farb et al., 2007, Grant et al., 2011; Segal et al., 1999). Specifically, mindfulness may increase active emotion focused coping and emotional expression. This occurs when mindful individuals accept their current situation and accept their emotions instead of holding it back (Chambers et al., 2009). Indeed, previous studies show that suppressing emotions can increase sympathetic nervous system activity and poor coping outcomes. Previous studies dealing with cancer patients suggest that emotional suppression is maladaptive because it prohibits the acceptance of the present moment. Emotional suppression is associated with higher levels of self-reported distress (Classen, et. al., 1996), decreased positive emotions (Gross & Levenson, 1997), and a lower tolerance to pain (Elfant, et. al., 2008; Masedo & Esteve, 2007). When responding to social stressors, emotional expression facilitates more adaptability as it links mindfulness with fewer stress-related symptoms. This may be because mindfulness helps to tolerate anger states during anger-provoking stimuli (Weinstein et al., 2009; Chambers et al., 2009; Robins et al., 2012). Rather than avoiding this emotional effect, mindfulness enables one to notice the angered state and allows the individual to respond adaptively and overcome any behavioral problems that may arise (Baser, 2003; Wright, et. al., 2007). Thus, when an arising emotion occurs, individuals will begin to notice their thoughts and their current emotional state. Mindfulness Training and Stress Reactivity 6 This may explain why Creswell’s study showed an increased salivary cortisol response to the TSST for those in the mindfulness group while buffering psychological stress reactivity to a brief three-day mindfulness meditation training. The present study tested these two competing emotion regulation accounts – does mindfulness training, dispositional mindfulness, or both, reduce emotional reactivity (show less negative affect) or increase emotional expression (reduce emotional suppression) under stress? Moreover, do these emotion effects mediate the effects of mindfulness training on altering psychological and neuroendocrine stress reactivity to the TSST? We tested these competing accounts with measures of coded anger and anxiety behaviors during the TSST. Specifically, the emotional reactivity account predicts an increase in emotional buffering and the emotional expression account predicts an increase in emotional expression [for fear and anxiety]. Moreover, we tested whether mindfulness training and dispositional mindfulness increased behavioral measures of confidence and speech quality during the TSST. Method Participants Seventy-three (n=73) healthy male and female students (59% Male) from university campuses around Pittsburgh with an average age of 21.7 years old (SD = 2.91) participated in either a 3-day mindfulness meditation training or an attention training program. Participants identified themselves as Caucasian (33.3%), African American (4.5%), Asian American (31.8%), Latino (9.1%), and Others (21.2%). Participants were excluded from the study if they could not speak English, were not between the ages of 18 to 30 years of age, or used oral contraceptives like birth control. Three participants discontinued the study, three participants were excluded due Mindfulness Training and Stress Reactivity 7 to outlier dispositional mindfulness scores, and one participant was excluded for being administered the wrong study condition. Thus, a total of 66 participants were analyzed. Procedure Participants were informed to partake in an attention training study consisting of three separate sessions for three consecutive days. For all three days, participants completed a variety of questionnaires regarding current mood and thoughts followed by an attention training exercise. Participants were randomly assigned to either a three-day mindfulness meditation training or a three-day analytic attention training for about 25 minutes each. After the audio training session, participants completed another questionnaire assessing their current mood and thoughts. The only difference from Day 1 and Day 2 was that on the second day, physiological sensors and a blood pressure cuff was applied upon their arrival. On the third day, four cortisol samples were also taken, and they completed a challenging social evaluative stress task (the TSST) following the mindfulness meditation or cognitive training session. For the challenging social evaluative stress task (TSST), participants first completed a 5-minute speech addressing why one would be a good administrative assistant for the psychology department followed by a 5-minute difficult calculation task (counting backwards from 2083 by 17’s) in front of two evaluators who were trained to act in a cold and non-accepting manner during the whole performance task. For the present study, we collected videos of the participant’s face during the TSST to examine how people’s emotional responses are associated with stress response. Dependent Measures For all three days, participants filled out questionnaires about their current thoughts and feelings. During the second and third day of the attention study, physiological information was Mindfulness Training and Stress Reactivity 8 collected. We hypothesized that mindfulness meditation reduced stress response through the use of several physiological measures, including heart rate, blood pressure, and cortisol levels. To evaluate emotion processing effects, we developed a coding manual for assessing behaviors during the speech and math performance tasks of the TSST, which included measures of anger, anxiety, and confidence displays (see Behavioral Coding below). The overall quality of the speech was rated as well. Interventions Both attention training exercises were administered by having participants listen to audio files (via headphones) in the laboratory. The experimenter was blinded to the conditions by labeling conditions as either “1” or “2”. All audio training sessions were 25 minutes each for three sessions. Details of the training interventions are provided in Creswell et al., 2014. For the mindfulness meditation training exercise, participants learned how to foster attention and awareness to the present moment. The first session taught them focus around breathe awareness, and the second session progressed to a full body awareness. In the third session, participants practiced both breathe and body awareness along with emotional and thought awareness. For the analytic attention control attention training, participants developed an analytical focus for effective problem-solving. For all three sessions, participants listened to a series of poetry and were told to analyze the poem. Participants were asked to notice the structure and imagery of the poems and later evolved to analyzing the deeper meaning and well as symbolism on the final session.