Brain changes following mindfulness: Reduced caudate volume is associated with decreased positive urgency

Mindfulness training has been shown to improve psychological health and general well-being. However, it is unclear which brain and personality systems may be affected by this practice for improving adaptive behavior and quality of life. The present study explores the effects of a 5-week mindfulness-based intervention (MBI) at the neuroanatomical level and its relationship with dispositional mindfulness and impulsivity. Sixty-six risky drivers were quasi-randomly assigned to a mindfulness training group (MT) or a control group (N). Participants underwent magnetic resonance imaging and completed the Five Facet Mindfulness Questionnaire (FFMQ) and the UPPS-P impulsivity scale twice, at baseline and after receiving the MBI. We observed that MBI changes dispositional mindfulness in the non-reactivity and observing facets. Further, we observed that the magnitude of change in impulsivity was associated with the change in dispositional mindfulness. Whole-brain voxel-wise analysis revealed that the volume of the right caudate nucleus of the MT group (n = 27) showed a reduction compared to that of the control group (n = 33), which increased in terms of the pre-post measurement (MT=-1.76 mm3; N = 6.31 mm3). We also observed that reduced caudate nucleus volume correlated with decreased positive urgency in the MT group. Taken together, our results show that MBI improves the skills of observing and non-reactivity to inner experience, while producing changes in the structure of the caudate nucleus. These structural changes are associated with a reduction in impulsivity levels, decreasing the tendency to act rashly in situations that generate positive emotions and thus facilitating more adaptive behavior.

There Is More to Mindfulness Than Emotion Regulation: A Study on Brain Structural Networks

Dispositional mindfulness and emotion regulation are two psychological constructs closely interrelated, and both appear to improve with the long-term practice of mindfulness meditation. These constructs appear to be related to subcortical, prefrontal, and posterior brain areas involved in emotional processing, cognitive control, self-awareness, and mind wandering. However, no studies have yet discerned the neural basis of dispositional mindfulness that are minimally associated with emotion regulation. In the present study, we use a novel brain structural network analysis approach to study the relationship between structural networks and dispositional mindfulness, measured with two different and widely used instruments [Mindfulness Attention Awareness Scale (MAAS) and Five Facet Mindfulness Questionnaire (FFMQ)], taking into account the effect of emotion regulation difficulties. We observed a number of different brain regions associated with the different scales and dimensions. The total score of FFMQ and MAAS overlap with the bilateral parahippocampal and fusiform gyri. Additionally, MAAS scores were related to the bilateral hippocampus and the FFMQ total score to the right insula and bilateral amygdala. These results indicate that, depending on the instrument used, the characteristics measured could differ and could also involve different brain systems. However, it seems that brain areas related to emotional reactivity and semantic processing are generally related to Dispositional or trait mindfulness (DM), regardless of the instrument used.

Repeat Traffic Offenders Improve Their Performance in Risky Driving Situations and Have Fewer Accidents Following a Mindfulness-Based Intervention

Risky decision-making is highly influenced by emotions and can lead to fatal consequences. Attempts to reduce risk-taking include the use of mindfulness-based interventions (MBI), which have shown promising results for both emotion regulation (ER) and risk-taking. However, it is still unclear whether improved emotion regulation is the mechanism responsible for reduced risk-taking. In the present study, we explore the effect of a 5-week MBI on risky driving in a group of repeat traffic offenders by comparing them with non-repeat offenders and repeat offenders without training. We evaluated the driving behavior of the participants through a driving simulation, and self-reported emotion regulation, both before and after the intervention. At baseline, poor emotion regulation was related to a more unstable driving behavior, and speeding. The group that received mindfulness training showed improved performance during risky driving situations and had fewer accidents, although their overall driving behavior remained largely unchanged. The observed trend toward improved emotion regulation was not significant. We discuss whether other effects of MBI – such as self-regulation of attention – could underlie the observed reduction in risky driving in the initial stages. Nonetheless, our findings still confirm the close relationship between emotion regulation skills and risky driving.

Strength, Affect Regulation, and Subcortical Morphology in Military Pilots

INTRODUCTION

Previous studies have shown links of body composition and fitness measures with brain structure, as well as with different aspects of emotional adjustment and well-being. However, the possible role of trait emotion-regulation success in the relationship between fitness/body composition and emotion-related subcortical structures has never been directly addressed.

METHODS

Twenty-three elite helicopter pilots were assessed in fat mass percentage, an endurance test to volitional exhaustion, bench-press power output, and negative urgency (trait affect regulation failure). Their brains were scanned using magnetic resonance imaging to estimate the size of the accumbens/amygdala, considered together, and the thalamus. Resulting correlations were used to test the relationship between body composition/fitness measures and brain structures' size, and the role of negative urgency therein, using structural equation modeling.

RESULTS

Fat mass percentage was associated with the size of the thalamus and the amygdala/accumbens. In the latter case, negative urgency and bench-press power output predicted structure size (and explained the effect of fat mass percentage away). In other words, bench-press power output and emotion regulation success (but not endurance performance) were associated with a larger amygdala/accumbens size.

CONCLUSIONS

Bench-press power output and emotion regulation success are independently associated with a larger amygdala/accumbens size, although present evidence does not allow for determination of causal directionality.