Brief mindfulness training can mitigate the influence of prior expectations on pain perception.

BACKGROUND: Recent neuroimaging evidence suggests that mindfulness practice may mitigate the biasing influence of prior cognitive and emotional expectations on pain perception. The current study tested this hypothesis using a pain-cueing paradigm, which has reliably been shown to elicit conditioned hypoalgesic and hyperalgesic effects. Specifically, we aimed to investigate whether the instructed use of a mindfulness compared to a suppression strategy differentially modulates the magnitudes of conditioned hypoalgesia and hyperalgesia. METHODS: Sixty-two healthy non-meditators were assigned to listen to either brief mindfulness or suppression instructions, in between the conditioning and testing phases of a pain-cueing task. Participants provided ratings of anticipatory anxiety, pain intensity and pain unpleasantness throughout the task. They also completed trait and state self-report measures of mindfulness and pain catastrophizing. RESULTS: Results indicated that the paradigm was successful in inducing conditioned hyperalgesic and hypoalgesic effects. Importantly, while we found evidence of cue-induced hyperalgesia in both groups, only the suppression group reported cue-induced hypoalgesia. No group differences in pain ratings were found for unconditioned (novel-cued) stimuli. CONCLUSIONS: These findings provide partial support for recently proposed predictive processing models, which posit that mindfulness may lead to a prioritization of current sensory information over previous expectations. We explore potential explanations for the asymmetrical group differences in conditioned hypoalgesia versus conditioned hyperalgesia, and discuss our results in light of recent neuroimaging insights into the neuropsychological mechanisms of mindfulness and expectancy-driven pain modulation. SIGNIFICANCE: The current study provides novel insights into the working mechanisms of mindfulness-driven pain modulation. Our data suggest that brief mindfulness training may reduce the influence of prior beliefs and expectations on pain perception. This finding adds to growing evidence suggesting that mindfulness may alleviate pain via neuropsychological mechanisms opposite to those typically observed in conditioning/placebo procedures and other cognitive manipulations. These unique mechanisms underline the potential of mindfulness as an alternative to traditional cognitive pain regulatory strategies.

Effects of Cold Stimulation on Cardiac-Vagal Activation in Healthy Participants: Randomized Controlled Trial.

BACKGROUND: The experience of psychological stress has not yet been adequately tackled with digital technology by catering to healthy individuals who wish to reduce their acute stress levels. For the design of digitally mediated solutions, physiological mechanisms need to be investigated that have the potential to induce relaxation with the help of technology. Research has shown that physiological mechanisms embodied in the face and neck regions are effective for diminishing stress-related symptoms. Our study expands on these areas with the design for a wearable in mind. As this study charts new territory in research, it also is a first evaluation of the viability for a wearables concept to reduce stress. OBJECTIVE: The objectives of this study were to assess whether (1) heart rate variability would increase and (2) heart rate would decrease during cold stimulation using a thermode device compared with a (nonstimulated) control condition. We expected effects in particular in the neck and cheek regions and less in the forearm area. METHODS: The study was a fully randomized, within-participant design. Volunteer participants were seated in a laboratory chair and tested with cold stimulation on the right side of the body. A thermode was placed on the neck, cheek, and forearm. We recorded and subsequently analyzed participants' electrocardiogram. The cold stimulation was applied in 16-second intervals over 4 trials per testing location. The control condition proceeded exactly like the cold condition, except we manipulated the temperature variable to remain at the baseline temperature. We measured heart rate as interbeat intervals in milliseconds and analyzed root mean square of successive differences to index heart rate variability. We analyzed data using a repeated-measures ANOVA (analysis of variance) approach with 2 repeated-measures factors: body location (neck, cheek, forearm) and condition (cold, control). RESULTS: Data analysis of 61 participants (after exclusion of outliers) showed a main effect and an interaction effect for body location and for condition, for both heart rate and heart rate variability. The results demonstrate a pattern of cardiovascular reactivity to cold stimulation, suggesting an increase in cardiac-vagal activation. The effect was significant for cold stimulation in the lateral neck area. CONCLUSIONS: The results confirmed our main hypothesis that cold stimulation at the lateral neck region would result in higher heart rate variability and lower heart rate than in the control condition. This sets the stage for further investigations of stress reduction potential in the neck region by developing a wearable prototype that can be used for cold application. Future studies should include a stress condition, test for a range of temperatures and durations, and collect self-report data on perceived stress levels to advance findings.