Association Between Baseline Corticothalamic-Mediated Inhibitory Control and Smoking Relapse Vulnerability.

Importance: Tobacco use disorder is associated with dysregulated neurocognitive function in the right inferior frontal gyrus (IFG)-one node in a corticothalamic inhibitory control (IC) network. Objective: To examine associations between IC neural circuitry structure and function and lapse/relapse vulnerability in 2 independent studies of adult smokers. Design, Setting, and Participants: In study 1, treatment-seeking smokers (n = 81) completed an IC task during functional magnetic resonance imaging (fMRI) before making a quit attempt and then were followed up for 10 weeks after their quit date. In study 2, a separate group of smokers (n = 26) performed the same IC task during fMRI, followed by completing a laboratory-based smoking relapse analog task. Study 1 was performed at Duke University Medical Center between 2008 and 2012; study 2 was conducted at the Medical University of South Carolina between 2013 and 2016. Main Outcomes and Measures: Associations between corticothalamic-mediated IC, gray-matter volume, and smoking lapse/relapse. Results: Of the 81 study participants in study 1 (cessation study), 45 were women (56%), with mean (SD) age, 38.4 (10.2) years. In study 1, smoking relapse was associated with less gray-matter volume (F1,74 = 28.32; familywise error P threshold = 0.03), greater IC task-related blood oxygenation level-dependent (BOLD) response in the right IFG (F1,78 = 14.87) and thalamus (F1,78 = 14.97) (P < .05), and weaker corticothalamic task-based functional connectivity (tbFC) (F1,77 = 5.87; P = .02). Of the 26 participants in study 2 (laboratory study), 15 were women (58%), with mean (SD) age, 34.9 (10.3). Similar to study 1, in study 2, greater IC-BOLD response in the right IFG (t23 = -2.49; ß = -0.47; P = .02), and weaker corticothalamic tbFC (t22 = 5.62; ß = 0.79; P < .001) were associated with smoking sooner during the smoking relapse-analog task. In both studies, corticothalamic tbFC mediated the association between IC performance and smoking outcomes. Conclusions and Relevance: In these 2 studies, baseline differences in corticothalamic circuitry function were associated with mediated IC and smoking relapse vulnerability. These findings warrant further examination of interventions for augmenting corticothalamic neurotransmission and enhancing IC during the course of tobacco use disorder treatment.

Meditation-State Functional Connectivity (msFC): Strengthening of the Dorsal Attention Network and Beyond.

Meditation practice alters intrinsic resting-state functional connectivity (rsFC) in the default mode network (DMN). However, little is known regarding the effects of meditation on other resting-state networks. The aim of current study was to investigate the effects of meditation experience and meditation-state functional connectivity (msFC) on multiple resting-state networks (RSNs). Meditation practitioners (MPs) performed two 5-minute scans, one during rest, one while meditating. A meditation naïve control group (CG) underwent one resting-state scan. Exploratory regression analyses of the relations between years of meditation practice and rsFC and msFC were conducted. During resting-state, MP as compared to CG exhibited greater rsFC within the Dorsal Attention Network (DAN). Among MP, meditation, as compared to rest, strengthened FC between the DAN and DMN and Salience network whereas it decreased FC between the DAN, dorsal medial PFC, and insula. Regression analyses revealed positive correlations between the number of years of meditation experience and msFC between DAN, thalamus, and anterior parietal sulcus, whereas negative correlations between DAN, lateral and superior parietal, and insula. These findings suggest that the practice of meditation strengthens FC within the DAN as well as strengthens the coupling between distributed networks that are involved in attention, self-referential processes, and affective response.