By John M. de Castro, Ph.D.
“the default mode network always takes you somewhere other than where you are. You are not focused on the immediate environment and will also be “time-travelling” in the past or future – never in the present moment. . . Interestingly, researchers have found that the default mode network is less active when people meditate.” – Mindful Call
Mindfulness is the ability to focus on what is transpiring in the present moment. It involves a greater emphasis on attention to the immediate stimulus environment. Mindful people generally have better attentional abilities and have fewer intrusive thoughts and less mind wandering. As a result, mindfulness has been shown to be associated with differences in thought processes. A system of the brain known as the Default Mode Network (DMN) becomes active during mind wandering and relatively quiet during focused on task behavior. It is involved when we are engaged in internally focused tasks such as recalling deeply personal memories, daydreaming, sleeping, imagining the future and trying to take the perspective of others. The DMN involves neural structures including the medial prefrontal cortex, anterior and posterior cingulate cortices, precuneus, inferior parietal cortex, and lateral temporal cortex. These areas of the DMN are functionally connected, such that they are simultaneously active during mind wandering.
Mindfulness training has been shown to alter the size and activity of neural structures including reducing the size and activity in the Default Mode Network (DMN) as a result of neuroplasticity. The DMN, however, is a network of interconnected structures which are, in turn, connected to a number of other neural structures. This interconnectivity reflects the ability of these structures to affect other structures in the brain, in other words, the effects of mind wandering on other brain systems. Hence, it is important to investigate the effects of mindfulness training on the functional connectivity of the structures of the Default Mode Network (DMN) and the neural structures connected to these structures.
In today’s Research News article “Data for default network reduced functional connectivity in meditators, negatively correlated with meditation expertise.” See:
or see summary below or view the full text of the study at:
http://www.sciencedirect.com/science/article/pii/S2352340916304504
Berkovich-Ohana and colleagues performed functional Magnetic Resonance Imaging (fMRI) of the brains of experienced meditators in comparison to similar individuals who did not meditate while at rest and during meditation.
They found that at rest the functional connectivity within the structures of the DMN and within the neural structures associated with vision were lower in meditators and that this functional connectivity decreased during meditation. They also found that the meditators had greater functional connectivity between the DMN and the visual system structures than the non-meditators and this also decreased during meditation. In addition, they found that the greater the experience with meditation the lower the functional connectivity between the DMN and other neural structures. These findings suggest that meditation lowers the ability of the structures associated with mind wandering to affect other structures in the nervous system. They also suggest that meditation practice produces less internal connectivity within these structures underlying mind wandering. Finally, these findings suggest that visualizations dissociated from the focus of attention may be higher in the meditators. This may indicate that when meditators’ minds wander they contain more vivid visual imagery.
These data are interesting and demonstrate that meditation alters the internal connectivity of the structures that produce mind wandering and their ability to affect other neural structures. Hence, the functional connectivity of brain structures reflects the experiences of meditators of reduced mind wandering. Meditation appears to change the brain to produce less mind wandering.
So, reduce mind wandering produced by the brain with mindfulness.
“What may happen when people practise mindfulness is that, over time, this weakens the connection between their thalamus and the rest of the default mode network. Their trait mindfulness score would climb as a result and they might just become more mentally robust and less prone to depression and other mental illnesses. That really would be brain plasticity in action.” – Plastic Brain
CMCS – Center for Mindfulness and Contemplative Studies
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Study Summary
Berkovich-Ohana A, Harel M, Hahamy A, Arieli A, Malach R. Data for default network reduced functional connectivity in meditators, negatively correlated with meditation expertise. Data Brief. 2016 Jul 15;8:910-4. doi: 10.1016/j.dib.2016.07.015. eCollection 2016 Sep. PMID: 2750824
Abstract
FMRI data described here was recorded during resting-state in Mindfulness Meditators (MM) and control participants (see “Task-induced activity and resting-state fluctuations undergo similar alterations in visual and DMN areas of long-term meditators” Berkovich-Ohana et al. (2016) [1] for details). MM participants were also scanned during meditation. Analyses focused on functional connectivity within and between the default mode network (DMN) and visual network (Vis). Here we show data demonstrating that: 1) Functional connectivity within the DMN and the Visual networks were higher in the control group than in the meditators; 2) Data show an increase for the functional connectivity between the DMN and the Visual networks in the meditators compared to controls; 3) Data demonstrate that functional connectivity both within and between networks reduces during meditation, compared to the resting-state; and 4) A significant negative correlation was found between DMN functional connectivity and meditation expertise.
http://www.sciencedirect.com/science/article/pii/S2352340916304504
On Meditation, Mind Wandering, and Meaning (a complementary perspective)
Meditation, from focal meditation to mindfulness entails the avoidance of all conscious discursive or unpredictable transitive (act-outcome) or ‘what if’ decision making or judgment that represents past, present and future judgments that can easily transition into perseverative thought (i.e. regret, distraction, and worry). In other words, meditation is reducing discursive thinking by being in the moment or ‘mindful’. The avoidance of discursive thinking or ‘mind wandering’ prevents the development of future perseverative conflicts and results in the covert musculature becoming inactive, or a pleasurable state of rest. Relaxation is achieved by avoiding discursive judgment rather than all judgment, while anticipated and subsequent non-discursive or meaningful behavior sustains and enhances the positive affect due to relaxation both during and after meditation sessions. (This is exemplified in cognitive strategies such as savoring, loving-kindness meditation, and flow experiences that couple positive ideation with relaxed states) Thus meditation, to be effective or most ‘affective’, must represent a dual cognitive strategy that couples the inhibition of discursive thinking with subsequent non-discursive or meaningful judgment or thought.
A more formal explanation from a neurologically based learning theory is provided on pp. 47-52 in a little open-source book on the psychology of rest linked below. (The flow experience is discussed on pp. 81-86.)
https://www.scribd.com/doc/284056765/The-Book-of-Rest-The-Odd-Psychology-of-Doing-Nothing