The beneficial effects of meditation: contribution of the anterior cingulate and locus coeruleus

Abstract

During functional magnetic resonance imaging studies of meditation the cortical salience detecting and executive networks become active during “awareness of mind wandering,” “shifting,” and “sustained attention.” The anterior cingulate (AC) is activated during “awareness of mind wandering.” The AC modulates both the peripheral sympathetic nervous system (SNS) and the central locus coeruleus (LC) norepinephrine systems, which form the principal neuromodulatory system, regulating in multiple ways both neuronal and non-neuronal cells to maximize adaptation in changing environments. The LC is the primary source of central norepinephrine (C-NE) and nearly the exclusive source of cortical norepinephrine. Normally activated by novel or salient stimuli, the AC initially inhibits the SNS reflexively, lowering peripheral norepinephrine and activates the LC, increasing C-NE. Moderate levels of C-NE enhance working memory through alpha 2 adrenergic receptors, while higher levels of C-NE, acting on alpha 1 and beta receptors, enhance other executive network functions such as the stopping of ongoing behavior, attentional set-shifting, and sustained attention. The actions of the AC on both the central and peripheral noradrenergic systems are implicated in the beneficial effects of meditation. This paper will explore some of the known functions and interrelationships of the AC, SNS, and LC with respect to their possible relevance to meditation.

Noradrenergic stimulation modulates activation of extinction-related brain regions and enhances contextual extinction learning without affecting renewal

“…Other regions that showed higher activation in the ATO group during extinction learning presumably also support facilitated extinction learning, such as distinct regions in insula and anterior cingulate that were more active in both the ABA and AAA condition. Anterior cingulate and anterior insula together have been suggested to constitute a salience detecting network (Sridharan et al, 2008 ; Vincent et al, 2008 ; Menon and Uddin, 2010 ; Craigmyle, 2013 ). In the context of an overall role of insula in processing salience (Menon and Uddin, 2010 ), activation of the region in the processing of feedback (regardless of valence) has been found (Bischoff-Grethe et al, 2009 ).…”

Coupling of respiration and attention via the locus coeruleus: Effects of meditation and pranayama

“…Given the wide-ranging influence that the LC has on attention, respiration, and autonomic activity, it is unsurprising that it has been hypothesized to play an important role in the effects of meditation. Craigmyle (2013) theorizes that via activation by the ACC, which is a part of the salience, orienting, and executive attention networks (Peterson & Posner 2012;Posner & Petersen, 1990), the LC adapts the cortical and peripheral nervous systems of the organism to optimize behavior to a constantly changing environment, and that meditation improves the individual's ability to do this. Importantly, cortical NA has been directly observed to decrease during meditation (Infante et al, 2001;Walton, Pugh, Gelderloos, & Macrae, 1995), and increased gray matter density in the pons (the location of the LC and other important respiratory nuclei) has been found in a crosssection of long-term breath-focused meditators (Vestergaard-Poulsen et al, 2009), as well as in a randomized study (Holzel et al, 2011).…”

Does mindfulness meditation improve attention in attention deficit hyperactivity disorder?

“…The use of meditation with ADHD populations is in its nascence [48] . In 2008, Zylowska et al [32] conducted a feasibility study, which adapted MT for adolescents and adults with ADHD.…”