TDCS and Meditation: Can tDCS help you meditate?

In an increasingly busy and stressful modern world, mindfulness meditation is gaining widespread attention for its effectiveness in combating stress and enhancing concentration. Technology —i.e., the Internet, smart phones, and social media—can damage brain networks if not used properly. They cause damage by interrupting attention, encouraging immediate gratification, and fostering impulsiveness. Chronic stress —another major consequence of the modern world—also damages brain networks. Chronic stress can lead to impaired concentration, memory, and sleep, and increases a person’s susceptibility to depression and anxiety. Chronic stress has been shown to decrease the size of brain structures involved in concentration, memory formation, and emotional regulation, thus increasing the risk for concentration difficulties and mood disorders (depression, anxiety).

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Practicing mindfulness meditation can reverse the breakdown of brain circuits caused by chronic stress and modern technologies. Mindfulness refers to a nonjudgmental state of attention towards the present moment, resulting in active control of attention. Jon Kabat-Zinn ( a famous teacher of mindfulness) defines being mindful as:

“paying attention in a particular way; on purpose, in the present moment, and non-judgmentally.”

A popular technique to learn mindfulness is called ‘mindfulness-based training (MBT).’ There are two major MBT techniques. The first involves focusing on the breath. When one’s mind wanders, the attention is gently and non-judgmentally directed back to the breath. This type of mindfulness practice is called “Focused Attention.”

The second type of MBT is called “Open Monitoring,” and involves placing attention on any rising sensations in the body (i.e., warm tingling feelings in the arms/legs, gurgling of the belly, feeling your heart beating, etc) that occur during meditation.

Studies show that practicing mindfulness meditation improves memory and concentration, and alleviates anxiety and depression. Mindfulness meditation is exercise for the brain, much like weight training or a cardio workout is exercise for the body. Regular mindfulness practice gently exercises the brain ‘muscles’ that allow you to control your focus. Therefore, meditators who practice mindfulness are able to focus more easily on daily tasks and can more easily direct their attention away from ruminating/stressful thoughts.

Meditators have demonstrated neuroanatomical and functional connectivity differences in the brain compared to non-meditators. People who meditate have increased volume in the hippocampus and frontal grey matter (both regions that are affected by stress). This suggests that neurological benefits of meditation can fight against neurological changes from stress.

However, meditation needs to be practiced regularly and requires hours of dedicated training. People who try to learn how to meditate often give up because the learning curve is steep and it can seem too demanding.

Is there a way to make meditation easier and encourage people to do it more regularly??

Transcranial direct current stimulation (tDCS) is a technique that involves electrical stimulation of the brain (via scalp electrodes) to enhance activity in particular brain regions (for more information on tDCS, see my article, What is tDCS?). There is growing evidence demonstrating that tDCS may be effective for certain psychiatric and neurological disorders. TDCS seems to be most effective when paired with a task, thus synergistically enhancing the effects of the task (see my article on neuropriming and tDCS).

Recently, researchers are studying tDCS’s effects on mindfulness meditation and whether tDCS can help people learn to meditate more easily. Meditation retreats are beginning to use tDCS to enhance mindfulness of their participants - the first of these retreats occurred in fall of 2018.

CAN tDCS enhance mindfulness meditation?

A randomized pilot study published in 2017 of fifteen people found a trend for tDCS+audio guided meditation sessions to decrease sadness and restlessness, and enhance feelings of excitement and calmness compared to sham*-TDCS(see bottom of page for definition of sham-tDCS) + audio guided meditation. However these results were not statistically significant (perhaps because of the low number of people in the study, N=15 +/- the short duration of the study - 3 weeks, with only one tDCS session per week).

Another pilot study published in 2017 measured whether tDCS combined with Loving Kindness Meditation (LKM) could enhance emotional intelligence. The study used two different tDCS protocols. One protocol used anodal stimulation of the left dorsolateral prefrontal cortex (DLPFC; F3) and the other protocol used anodal stimulation of the right temporoparietal junction (TPJ; CP6). Both protocols used cathodal stimulation of the opposite upper arm. Both the sham and active tDCS stimulation of the right TPJ + LKM resulted improved subjective positive mood. Stimulation of the left DLPFC resulted in no effects.

Can tDCS + meditation improve memory and concentration?

In July, 2018, a randomized control study was published that compared tDCS + Mindfulness based training (MBT) against sham tDCS + relaxation techniques (reading/writing in a journal). The tDCS protocol involved anodal stimulation of the right frontal cortex (F10) and cathodal stimulation of the left upper bicep. Participants underwent 30 minutes of tDCS during stimulation sessions. Meditation sessions were 30 minutes per day, 5 days per week, for 4 weeks. tDCS was performed with meditation sessions 2 days per week. Participants in the tDCS+MBT group showed improved performance during difficult/complex working memory tasks and visuospatial memory tasks.

TDCS+MBT also improved neural efficiency of cognitive tasks based on EEG data. In other words, the brain waves of people in the tDCS+MBT group demonstrated increased efficiency of brain functioning during highly demanding cognitive tasks.

A major limitation of this study was that it did not isolate the effects of tDCS + MBT against MBT alone. In other words, it did not test whether tDCS+MBT is better than MBT alone. Instead, it measured the effects of tDCS+MBT against sham tDCS with simple relaxation techniques.

Interestingly, more people in the control group dropped out of the study than people in the tDCS+MBT group - does this suggest that tDCS can make it easier to stick with a meditation regimen? Hard to make conclusions like that with such a small number of study participants, but it’s definitely something worth keeping in mind for future studies.

Conclusions:

There are few publications that study tDCS+meditation training (because this area of research is relatively new), so it is difficult to make conclusions about whether tDCS can enhance meditation. Hopefully future research will allow us to make more definitive conclusions. The few published articles reveal mixed results about whether tDCS can facilitate learning meditation. The results of the single study measuring tDCS+MBT effects on memory and concentration are quite promising. This study suggests that tDCS+meditation training can enhance concentration, working memory, and efficiency of brain networks. However more studies need to be performed in order to come to any solid conclusions.

Below are the tDCS protocols used in the two studies showing promising results, for anyone who is interested:

1. tDCS+mindfulness meditation training enhances working memory and visuospatial memory - statistically significant

Anode = F10. Cathode = left upper bicep; current = 2.0mA. Duration of stimulation = 30 minutes. Meditation sessions 30 minutes per day, 5 days per week, for 4 weeks. TDCS was performed with meditation sessions on 2 days per week.

2. tDCS+audio guided meditation - decreased sadness and restlessness, enhanced excitement and calmness - trend, not statistically significant

Anode = F8. Cathode = left supraorbital, current = 1 or 2 mA. Duration of stimulation = 20 minutes + simultaneous audio guided meditation. Session conducted once per week for three weeks.

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Neurogal MD’s personal regimen:

Some might be interested in my anecdotal experience with tDCS and meditation, so I thought I would share that with you. Please note this is strictly anecdotal (n=1). I began using tDCS in 2016. Depression runs in my family, and so throughout my life I have experienced periods of depression. These periods were more frequent (and more intense) during my residency and medical school years. When I graduated from medical training, a low lying depression lingered, probably because the neural circuits involved in depressive mood had become particularly strong during my medical training. I began to personally use tDCS on myself the year after residency. I used it daily for 4 weeks for 20 minutes each day (Anode F3, Cathode Fp2), and practiced focused-breathing meditation with each session. I personally noticed significant improvements in my mood, and motivation, confirmed by objective measurements (a daily emotion/mood scale) that I used to track my mood over time.

I now use tDCS as maintenance, using it once every 2-3 weeks, and I practice yoga 3-4 times a week (when I am not on call). I mention yoga because the involved physical postures also allow me to meditate more easily. I am going to write a post about the neurological benefits of yoga soon. Stay tuned.



*sham TDCS involves placing electrodes on the head but not actually turning stimulation parameters on throughout the entire session. Sham tDCS helps to account for the placebo effect of having electrodes placed on the head.