So I’m stimulating this “vagus nerve”, but what is it exactly? The vagus nerve is one of the longest and most intricate nerves of our body. It runs from the brain all the way down to the major organs. The nerve is crucial in regulating much of the involuntary processes of the body, such as heart rate, breathing, digestion and immune system response. Sub optimal vagus nerve activation has been linked to impaired cognitive ability, inflammation and depression among others.
By stimulating a specific part of the vagus nerve located in the left ear, it can activate several restorative pathways. This particular left ear application focuses on the parasympathetic branch of the nervous system that is mainly associated with relaxation and recovery.
An unexpected side effect is that when meditating, it quickly brings me into a super deep state of relaxation, which makes it very powerful to unwind even more if I’m willing to make an extra effort.
When in use, you just feel a little tingling in your ear. You can also tweak the settings so that you don’t notice it at all. Either way it isn’t even distracting, except for the persons around you of course 
There are quite some devices that basically all do the same thing. At first I was looking at a premium option (parasym.co) that included an accompanying sound therapy for tinnitus (which I also struggle with), but the high price put me off.
Then I stumbled upon a dutch company selling a prototype earpiece especially designed for this purpose. The earpiece runs about €90 and can easily be hooked up to a control unit from the same company, which you have to buy separately.
Update 11.03.21 Unfortunately the company discontinued the product recently. You can still get the other premium option that I mentioned before.
There is also the option of a very cheap universal clip which you click on your ear. I haven’t tried this myself as according to the research precise placement is key so a more custom earpiece seems like a smart choice. Also comfort comes into play, as securely clamping something on my ear for longer periods of time doesn’t seem that appealing.
The control unit provides the actual microcurrent. I really wanted granular control for a precise tuning as I’m sending current through my body. So I ended up with a more expensive device that I initially was planning to, but in hindsight I’m glad I did. The small half current steps are really subtle and I use them all the time. This particular unit is about €250 and is called the TENS eco 2 by Schwa-Medico.
I have experimented a lot with the settings and depending on my mood and goal, I usually end up between 10 and 25Hz with a microcurrent of around 2 microamps (mA). That 2 mA is often the threshold to just feel a little tingling in my ear. One thing I have noticed is that the higher my cognitive fatigue the more microcurrent I have to use to “feel” the effects. In those situations I have used around 5 mA for a short period of time.
You can do multiple sessions per day, but like mentioned I regularly do just one in the evening ranging between 15 to 60 minutes. There are also good guidelines provided in the earpiece manual.
In the footnote, you can find some research papers which provide extra background information and the settings that were used in the clinical situations.
You can also activate the same vagus nerve pathways in more traditional ways. Gargling with water, humming and especially singing should work. Although from my experience these are way less effective. But this could very well be related to the quality of my singing 😉
Has anyone else tried (this type of) neuromodulation? Please share, as I think it can be very helpful for others with the same challenges
Steenbergen L., Sellaro R., Stock A.K., Verkuil B., Beste C. & Colzato L.S. (2015), Transcutaneous vagus nerve stimulation (tVNS) enhances response selection during action cascading processes, European Neuropsychopharmacology 25(6): 773-778.
Colzato, L. S., Ritter, S. M., & Steenbergen, L. (2018). Transcutaneous vagus nerve stimulation (tVNS) enhances divergent thinking. Neuropsychologia, 111, 72-76
Fang J, Rong P, Hong Y, et al. Transcutaneous Vagus Nerve Stimulation Modulates Default Mode Network in Major Depressive Disorder. Biol Psychiatry 2016;79:266–73. doi:10.1016/j.biopsych.2015.03.025
Goldberger JJ, Challapalli S, Tung R, et al. Relationship of Heart Rate Variability to Parasympathetic Effect. Circulation 2001;103:1977–83. doi:10.1161/01.CIR.103.15.1977