A self-referential default brain state: patterns of coherence,power, and eLORETA sources during eyes-closed rest and Transcendental Meditation practice

Activation of a default mode network (DMN) including frontal and parietal midline structures varies with cognitive load, being more active during low-load tasks and less active during high-load tasks requiring executive control. Meditation practices entail various degrees of cognitive control. Thus, DMN activation patterns could give insight into the nature of meditation practices. This 10-week random assignment study compared theta2, alpha1, alpha2, beta1, beta2 and gamma EEG coherence, power, and eLORETA cortical sources during eyes-closed rest and Transcendental Meditation (TM) practice in 38 male and female college students, average age 23.7 years. Significant brainwave differences were seen between groups. Compared to eyes-closed rest, TM practice led to higher alpha1 frontal log-power, and lower beta1 and gamma frontal and parietal log-power; higher frontal and parietal alpha1 interhemispheric coherence and higher frontal and frontal-central beta2 intrahemispheric coherence. eLORETA analysis identified sources of alpha1 activity in midline cortical regions that overlapped with the DMN. Greater activation in areas that overlap the DMN during TM practice suggests that meditation practice may lead to a foundational or ‘ground’ state of cerebral functioning that may underlie eyes-closed rest and more focused cognitive processes.     

Associations between childhood adversity and daily suppression and avoidance in response to stress in adulthood: can neurobiological sensitivity help explain this relationship?

Background and objectives: Although it has been postulated that psychological responses to stress in adulthood are grounded in childhood experiences in the family environment, evidence has been inconsistent. This study tested whether two putative measures of neurobiological sensitivity (vagal flexibility and attentional capacity) moderated the relation between women’s reported exposure to a risky childhood environment and current engagement in suppressive or avoidant coping in response to daily stress.

Design and methods: Adult women (N?=?158) recruited for a study of stress, coping, and aging reported on early adversity (EA) in their childhood family environment and completed a week-long daily diary in which they described their most stressful event of the day and indicated the degree to which they used suppression or avoidance in response to that event. In addition, women completed a visual tracking task during which heart rate variability and attentional capacity were assessed.

Results: Multilevel mixed modeling analyses revealed that greater EA predicted greater suppression and avoidance only among women with higher attentional capacity. Similarly, greater EA predicted greater use of suppression, but only among women with greater vagal flexibility.

Conclusion: Childhood adversity may predispose individuals with high neurobiological sensitivity to a lifetime of maladaptive coping.