22 November 2011

Meditation as Treatment for Schizophrenia, Autism, Alzheimer's?

Dr. Judson Brewer, medical director of the Yale Therapeutic Neuroscience Clinic, and his colleagues asked 10 experienced meditators and 13 people with no meditation experience to practice three basic meditation techniques: concentration, loving-kindness, and choiceless awareness.

...In a report published today in the Proceedings of the National Academy of Sciences, Brewer and his team report that the experienced meditators had decreased activity in an area of the brain called the default mode network, a region that is usually at work when the mind wanders. Even when the meditators weren't meditating, this region of their brain was much quieter than in their inexperienced counterparts. _ABCNews
The areas shaded in blue highlight areas of decreased activity in the brains of meditators

The Yale team conducted functional magnetic resonance imaging scans on both experienced and novice meditators as they practiced three different meditation techniques.

They found that experienced meditators had decreased activity in areas of the brain called the default mode network, which has been implicated in lapses of attention and disorders such as anxiety, attention deficit and hyperactivity disorder, and even the buildup of beta amyloid plaques in Alzheimer's disease. The decrease in activity in this network, consisting of the medial prefrontal and posterior cingulate cortex, was seen in experienced meditators regardless of the type of meditation they were doing.

The scans also showed that when the default mode network was active, brain regions associated with self-monitoring and cognitive control were co-activated in experienced meditators but not novices. This may indicate that meditators are constantly monitoring and suppressing the emergence of "me" thoughts, or mind-wandering. In pathological forms, these states are associated with diseases such as autism and schizophrenia.

The meditators did this both during meditation, and also when just resting — not being told to do anything in particular. This may indicate that meditators have developed a "new" default mode in which there is more present-centered awareness, and less "self"-centered, say the researchers. _MedicalXpress
In a similar vein the University of Wisconsin is planning a study early next year to investigate the neurological effects of meditation and yoga with veterans.

It is thought mindfulness meditation holds promise for post-traumatic stress disorder (PTSD), which provokes intrusive thoughts, emotional numbness and hypervigilance.

Mindfulness-based cognitive therapy (MBCT), which combines meditation with orthodox 'thought training', is already recommended for depression in Britain and is available on the NHS. _DailyMail

Related research:
Fourteen meditation practitioners performed breath-focused meditation while undergoing fMRI scanning. When participants realized their mind had wandered, they pressed a button and returned their focus to the breath. The four intervals above were then constructed around these button presses. We hypothesized that periods of mind wandering would be associated with default mode activity, whereas cognitive processes engaged during awareness of mind wandering, shifting of attention and sustained attention would engage attentional subnetworks. Analyses revealed activity in brain regions associated with the default mode during mind wandering, and in salience network regions during awareness of mind wandering. Elements of the executive network were active during shifting and sustained attention. Furthermore, activations during these cognitive phases were modulated by lifetime meditation experience. These findings support and extend theories about cognitive correlates of distributed brain networks. _Abstract_Hasenkamp 2011 j. neuroimage Emory U.

Depression and the default mode network:
Major depressive disorder (MDD) has been characterized by excessive default-network activation and connectivity with the subgenual cingulate. These hyper-connectivities are often interpreted as reflecting rumination, where MDDs perseverate on negative, self-referential thoughts. However, the relationship between connectivity and rumination has not been established. Furthermore, previous research has not examined how connectivity with the subgenual cingulate differs when individuals are engaged in a task or not. The purpose of the present study was to examine connectivity of the default network specifically in the subgenual cingulate both on- and off-task, and to examine the relationship between connectivity and rumination. Analyses using a seed-based connectivity approach revealed that MDDs show more neural functional connectivity between the posterior-cingulate cortex and the subgenual-cingulate cortex than healthy individuals during rest periods, but not during task engagement. Importantly, these rest-period connectivities correlated with behavioral measures of rumination and brooding, but not reflection. _OxfordJournals

This is a lot of material to take in at once -- particularly if you are not familiar with the concept of the "default mode network." But understanding this concept can make a big difference in your life, and in those lives which you may influence along the way.

The default mode network is a "stand-by" brain network, which is active when you are not attending to anything. It is a state of the wandering mind, which all too often falls into repetitive thought patterns which are too often dysfunctional for many people.

The studies above reveal that meditation practise can change the circuits involved in the default mode network in a way that tends to reduce brooding, intrusive thoughts, and rumination -- even during times when one is not meditating. Self-monitoring and cognitive control during default mode activation was increased in meditators, although the overall intensity of default mode network function was decreased.

This is crucial: The idle mind may not be a quiet or relaxed mind. In fact, it is often a tortured or depressed mind, which over time can make chronic diseases of the brain and mind more likely to set in. If you want your mind to be relaxed when it falls into its inevitable periods of default mode, you may want to consider meditation training.

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Blogger Whirlwind22 said...

Do shots and things like aspertame cause autism? If they do this sound like an interesting treatment choice.

Wednesday, 23 November, 2011  

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