Why I Love tDCS and the New tDCS Device from SSD

Introduction: Why I Love tDCS

I’ve been involved with transcranial direct current stimulation (tDCS) research and application for almost three years now.  When I stumbled upon it, I could not believe (like most of you) that something so simple could do so much good. A 9-volt battery curing depression, relieving chronic pain, improving memory, speeding learning, and much more – really?!  It turns out to be true.

(The new SSD tDCS Device. see below)

I’ve provided information on tDCS to dozens of people (thousands via my blog) with an array of needs and interests who have had great success helping themselves improve their lives through tDCS.  I could provide many examples, but here is one to illustrate my point:

A woman, (friend of the family), came to me describing deep, debilitating depression – to the point of becoming suicidal. Normally I would immediately refer such a person to Dr. James Fugedy, a tDCS practitioner in Atlanta – as I am a PhD, not MD.  But she had already failed on other kinds of treatments via other doctors, including medication, talk therapy, and was at the end of her rope. She was very, very depressed – but wanted to get better – she just had no idea how to go about it.

I talked to her about tDCS and the published information that shows improvement for some challenging depression cases. I showed her how to use a tDCS device and where studies have shown electrodes should be placed for treating depression – but left it up to her to treat herself or not.  She immediately started once-a-day 25 minute tDCS sessions (1.5 mA). Within five days her mood had lifted greatly and I think she had moved out of the suicide danger zone. She continued daily tDCS treatments for the next four weeks. As she did so, her depression fully lifted. She recovered so well that she felt motivated to enroll in a technical school to learn a new skill – and in her classes scored the highest on all tests (a side-effect of the tDCS?)

She now lives a normal, happy life (yes – with its ups and downs like anyone.)

Seeing people get their lives back in such a simple way, with no debilitating side-effects, has made me a cheerleader for tDCS.

Does it work for everyone? It won’t work for everyone – but what treatment (or pill) does? My observation is that tDCS works for those motivated and willing to consistently use it in the way research studies have shown it should be used. tDCS in combination with talk-therapy seems particularly well suited to treating depression – which in many has its roots in a brain dysfunction – not evil-spirits, selfishness, or a bad attitude as some suggest. By modifying the firing potential of the neurons in key portions of the brain it seems real healing can be achieved.

Review: New tDCS Device from SSD

Super Specific Devices has released a tDCS device that might be just right for that DIY tDCS person on your holiday shopping list (perhaps yourself!) The new tDCS device is a well-built variant of a DIY tDCS design that has floated around the internet for about two years now.

The Super Specific Devices (SSD) device offers solid performance, based on a 9 volt battery, and provides a feature I consider nearly essential – a meter that allows you to verify the current being delivered during your tDCS session.  That is coupled with a potentiometer (dial) that allows you to vary current level, making it easy to set 1, 1.5, or 2 mA or anywhere in between.  The user can also gently ramp current up and down using the dial – so discomfort and phosphenes are reduced or eliminated.

(Jack on the side for standard TENS style electrode cables)

What Comes in the Box

The SSD tDCS device is fully assembled and comes with a starter set of stick-on electrodes, a couple of sponges, a connecting wire, basic instructions, and a headband. The unit does not come with a 9 volt battery or any sort of an application manual.  Like many of the US-based cottage-industry building tDCS devices, they leave it up to the purchaser to do their own research on the internet to decide what additional electrodes, electrode placements, etc. are appropriate to the purchaser’s situation.  The intent is probably to keep the company off of the FDA’s radar as the SSD (and similar devices) are not marketed as medical devices – nor does the company provide medical advice.


To use the SSD tDCS device, one needs to insert a 9 volt battery into the socket on the side of the unit, plug in and apply electrodes, and then use the power on-off switch and dial to operate the unit.  To start a session, the dial should be rotated fully counter-clockwise (minimum current) and then switched on. An LED indicator just above the on-off switch will light to show that power is on.  Assuming electrodes are in place, the user then begins rotating the dial clockwise, watching the meter for rising current level.  Note that due to skin resistance, there is a lag between dialing in a higher current level and that level actually being achieved.  It can take a couple minutes or more for current to rise to a set level and stop. An alternative is to turn the dial significantly clockwise and turn it back down as your desired current level is achieved.

On my sample unit, even with electrodes shorted and the dial set fully clockwise, the unit would not deliver more than about 2.7 mA. On the inside is an LM 334 current regulator and a series-connected current limiting diode that limits output current to 2.7 mA – as I found in my testing (good safety feature). This is a nice, simple, practical, current control setup that should prove reliable for many, many years.

(Good build quality. LM 334, CRD and resistors on small circuit board, solder joints were solid, wires nicely dressed.)

Another nice feature of the SSD tDCS device is having a jack on the side of the unit for electrode wire attachment – it’s the standard TENS size that lets you use a variety of connecting wires supplied by Amazon, medical supply houses, etc.

(Electrode wire jack and current adjustment knob can be seen here.)

What Would I Change?

I’ve built several tDCS devices using the same basic design of the SSD tDCS unit.  So I’m very familiar with use, operation, and limitations of this type of device – and I’m allowed to nit-pick.

First, let’s be clear – it’s my opinion that this unit will operate as described by the company and will provide clean, regulated DC current for most common tDCS scenarios.

I happen to prefer using a type 23a 12 volt battery in my tDCS device designs.  Why? 9 volts is sometimes insufficient to overcome losses in the electronics, electrodes, and skin to provide the desired 1, 1.5 or 2 mA used in tDCS sessions.  In fact, 9 volts will probably not be sufficient if one of the electrodes is located on the shoulder or arm for a montage you wish to use. Sometimes a 12 volt battery will barely do it – but the additional 3 volts really seems to help. The downside of the type 23a battery is they don’t last long (2 or 3 months is normal with a lot of use.) But they, like 9 volt batteries (which last much longer in a tDCS device) are cheap (Amazon, Ebay.) I’m betting SSD went for long battery life (and easy availability of cheap batteries) in their design criteria.

( 9 v battery socket on the side. Aesthetically, it would be nicer to locate it inside the roomy box.)

By the way, many “commercial grade” tDCS devices use a voltage boost circuit that can raise delivered voltage to between 60 and 80 volts – as needed – to overcome skin and electrode resistance (like foc.us, Activa Dose II, and others). These boost circuits sometimes add discomfort for the user, increase device cost significantly, and so are not present in lower price tDCS devices like the one from SSD.


If you are looking for a well-built, inexpensive, tDCS device that includes a lot of good features (meter, adjustability, good current regulation and protection, and more) then this might just be the unit for you (or someone you know.)  You’ll need to do your own research on tDCS, its appropriateness for your situation, tDCS safety, and the electrode placements that address your need.  See any of the following as a starting point:




www.pubmed.gov (search for tdcs)

…and Google search tDCS

The Super Specific Devices tDCS device sells for $90 at http://www.superspecificdevices.com/ Oddly it sells for a bit more on ebay.com (go to ebay, search for tDCS). SSD also sells the same unit with a digital display for $20 more if you prefer (at their web site and ebay).

Based on my evaluation and use of a sample unit, it’s my opinion that the SSD tDCS device (design, build, and features) is a good value.


Almost Criminal – tDCS Still an Unknown Depression Treatment


This blog post deals with a very important topic: treating depression with tDCS. If you know anything at all about transcranial direct current stimulation (tDCS), you surely know that it has been shown in studies and anecdotal reports to have very positive effect on many depression patients – ranging from those with dysthymia to persons with severe, debilitating, drug resistant  depression.  It does not work for everyone, but what treatment does?

The beauty of tDCS is that it is incredibly simple, has a spotless safety record, has no significant side-effects, and with a little training can be used by a depression sufferer at home or wherever convenient.

Lets review some sobering facts: depression is a worldwide epidemic.  In the US alone, over 14 MILLION people suffer with some form of a major depressive disorder. About 1 in 10 adults now use some form of an antidepressant. Further, about 40,000 people per year commit suicide. (CDC)

What the numbers don’t tell you is that many suffering with depression don’t receive effective treatment – either because they don’t have access, can’t afford it, or commonly, are afraid of the public stigma of having to deal with a brain disorder. And lets be clear depression is a brain disorder.  For some, it can be treated effectively with “talk” therapy. But for many, depression is rooted in a brain physiology and chemistry problem and needs to be recognized and treated as such.

It really bothers me that mental health professionals are still mostly oblivious to the existence of tDCS and its potential benefits for the depressed. Every mental health professional should be aware of tDCS and use it when it seems appropriate – perhaps before or in conjunction with drug therapy.

Three Examples of tDCS Depression Treatment Montages

tDCS involves placing electrodes on the head and passing a very tiny direct current through them in order to achieve a desired effect.  Because the causes of depression are individualized, an electrode placement that works for one individual may not work for another. Current level may also need to be adjusted. It’s important that a depression patient being treated with tDCS be monitored to make sure progress is being made as treatments continue. If no improvement is detected after a few treatments, it may be time to try one of the other depression montages.

A normal depression treatment protocol is for 20 – 25 minutes of tDCS at 1, 1.5, or 2 mA at least 5 days per week for 30 days.  Treatment is sometimes continued for an additional 30 days for maximum result.  “Booster” treatments can be administered at anytime in the future as needed if depression symptoms begin to reappear. Some individuals are unable to tolerate 2 mA tDCS due to skin irritation.

Depression Montage #1

Image 1

The anode (+ lead) electrode is placed high on the left forehead while the cathode (- lead) electrode is placed on the right forehead. This is the most commonly used depression montage.


Depression Montage #2

image 2

The anode (+ lead) electrode is placed over the right temple while the cathode (- lead) electrode is placed over the left temple. This montage is interesting because not only can it alleviate depression, it is associated with improvements in intuitive thinking.

Depression Montage #3

image 3

image 4

The anode (+ lead) electrode is placed over the left forehead (supraorbital region) and the cathode ( – lead) is placed over the occipital region (middle of the back of the head, about even with the ears.) This is a recently published montage that showed very promising results in a small study.


Helpful References

If you are new to tDCS, may I suggest you at least examine the below:

1. www.speakwisdom.com

2. www.diytdcs.com

3. www.transcranialbrainstimulation.com

4. www.pubmed.gov (search for tDCS)

tDCS Devices

tDCS devices are entering the marketplace with increasing frequency. Here are some suggested consumer level devices to examine (in no particular order):

1. www.foc.us (buy with accessory kit)

2. www.tdcs-kit.com

3. thebrainstimulator.net

4. www.trans-cranial.com/tct/end-users-patients/tdcs-stimulator-products

5. www.cognitivekit.com

There are many more tDCS devices in the market, including impressive, expensive, professional models.


Its time for mental health professionals to get serious about helping their patients needing more than talk therapy with something other than a prescription drug. There is plenty of evidence and anecdote that tDCS can help many depression patients at the same level or better than medications – without all the side-effects and expense.  Do some research, attend a conference, speak to doctors now using tDCS and help end the epidemic of depression.

The Cognitive Kit, Stealth tDCS

tDCS Takes Off

It’s been amazing to watch the growth of interest in transcranial direct current stimulation (tDCS) over the last couple of years.  tDCS has moved from the obscurity of research center studies to a much wider audience via articles in the likes of Scientific American, the New York Times, Wired Magazine, assorted radio and TV bits, and of course the internet.

Many more people are at least peripherally aware that tDCS can help with depression, chronic pain, memory, learning, and more. Affordable tDCS devices have also become more available meaning fewer do-it-yourself types have to build their own.

At the lowest price are bare-bones 2 mA tDCS devices from www.tdcs-kit.com for less than $40 and a current-selectable unit from www.thebrainstimulator.net for less than $100.  Of course there are many tDCS devices at the opposite end of the spectrum that cost many hundreds to thousands of dollars.  But all accomplish the same task – providing a very small, regulated current to electrodes that are placed on the scalp in order to achieve a desired tDCS effect.

The Cognitive Kit

(The Cognitive Kit with my “test head”.  The test head allows me to simulate various montages, take measurements, scope wave-forms, etc.)

A new entry to the tDCS market has arrived and I have been fortunate to be able to review an early sample.  Human Bioelectric ( www.cognitivekit.com ) has released a new model, The Cognitive Kit, meant to target the higher end of the entry level market.  The Cognitive Kit is a current selectable tDCS device that comes with Amrex electrodes (the most popular choice of professional and advanced DIY tDCS users), a headband and use instructions. The unit is well built and likely to attract attention due to it’s stealth approach to packaging (no labels or anything that identifies what it is).  You can bet the TSA folks will want check it and have you to turn it on if you fly somewhere with it!

Human Bioelectric does not provide montage or medical advice. As with most DIY tDCS device suppliers, they leave it up to you to do your homework to decide which tDCS montage is right for you.  I presume all do this to keep themselves off of the FDA radar screen.


The Cognitive Kit is a slim package somewhat larger than a typical smartphone. There is an on-off slide switch on the side of the case and a current selector slide-switch and session start-stop push-button on top.  There is also an LED indicator for power and session in progress LED. The Cognitive Kit does not include a session timer (typical of devices in this price class).

(What is it? What are all the switches and lights for? The Cognitive Kit, Stealth tDCS)

Inside the box is a very nicely laid-out PC board containing all the major components.  The Cognitive Kit uses an LM234 (functionally identical to the LM334) for current regulation, coupled to a group of resistors and a selector switch that program the LM234 to limit current to 1, 1.5, or 2 mA depending on switch position. This is a very tried and tested design that should prove to be highly reliable and safe for many years of use.

(Neat and solid construction.  Should last for years.)

The Cognitive Kit uses two 9 volt batteries in series to supply 18 volts to the regulator board.  Why 18 volts instead of the 9 volts that some use?  One of the chief difficulties of a tDCS device is overcoming the highly variable resistance encountered depending on the position of the electrodes on the scalp, how wet they are, whether salt has been used, or if some other type of electrode is being use that has higher resistance (stick-on type for example).  In some cases 9 volt powered tDCS devices have a difficult time achieving 2 mA, or even 1 or 1.5 mA in a tDCS session because the lower voltage cannot overcome resistance in the “head circuit”.  The higher source voltage of  the Cognitive Kit helps overcome electrode, hair, skin, etc. resistance so it can more reliably deliver the selected current level. This is exactly the idea behind the “boost” circuits used in more expensive tDCS devices (and professional models) that boost the regulated voltage to 60 or 80 volts – and why some users of higher-end tDCS devices have received a frightening shock when they inadvertently pulled off electrodes during a tDCS session.

Using a lower voltage (9, 12, or 18), makes the tDCS device circuit much simpler to build, probably more reliable in the long-run, and eliminates the possibility of a high voltage shock.

Interestingly, Human Bioelectric claims that the Cognitive Kit has a built-in failure-mode current limit of 6 mA (for 2 k-Ohms of head resistance). In a device failure, 6 mA would be VERY uncomfortable, causing any user to immediately switch off the device or rip off the electrodes. According to what I’ve read, that current level would not do any damage in the brief time a user could tolerate it!

In Use

I set up the Cognitive Kit for several different common montages used in tDCS and found it to reliably deliver the selected current level and to be easy to use.


  • Wet electrodes (slightly saline water). Squeeze out excess water.
  • Place the electrodes in desired locations using a headband to hold them in place.
  • Turn on the Cognitive Kit (slide switch on side)
  • Select desired current level (slide switch on top)
  • Press button (on top) to Start tDCS session
  • Manually time 20 minute session
  • Press button (on top) to Stop tDCS session, switch off the Cognitive Kit
  • Remove electrodes from head (clean sponges as needed)

The montage for “savant learning”, for example, involves placing the anode (+) on the right temple and the cathode (-) on the left temple.  Doing that I found (about 4 k-Ohms of head resistance):

  • Switch set for 1 mA, I measured a current of 0.99 mA
  • Switch set for 1.5 mA, I measured a current of 1.53 mA
  • Switch set for 2.0 mA, I measured a current of 2.01 mA

These numbers show excellent regulation and were reliable with different montages.

One feature that all of the less expensive tDCS devices lack is a slow ramp-up, ramp-down circuit.  When you start a tDCS session, the Cognitive Kit current very quickly goes from zero to your selected level – delayed slightly by how long it takes water to saturate your skin and provide a good conductive path.  Because of this, you may see a weak phosphene (flash of light) as a tDCS session starts or ends. This can seem strange, but all the literature I’ve read indicates that phosphenes are harmless.

What I Like

  • Simple device, very easy to use
  • Low voltage so no possibility of a 60 or 80 volt shock
  • Rugged PC board design – should last many years
  • Amrex 3×3 sponges and headband included
  • Current limited in failure

What Could Use Improvement

  • Labeling the case would be useful and improve appearance (though some may prefer the stealth look)
  • LED brightness is very high (nit picking)
  • You must remove four screws on the back to replace batteries
  • I still love having a mA meter on a tDCS device – it’s an assurance

Final Comments

The Cognitive Kit sells for about $200 and comes complete with Amrex sponge electrodes, headband, connecting wires, and instructions.  Some may question the price, and yes, the Cognitive Kit could be sold for less if it were less solidly built and did not include Amrex 3×3 electrodes. A solid build is worth something and if you are serious about tDCS, no matter what tDCS device you buy, sooner or later you’ll be buying Amrex 3×3’s. They are not cheap! The Cognitive Kit and Amrex 3×3 combination should last you for years if taken care of. As the saying goes, “You get what you pay for”.

Operationally, the Cognitive Kit does what Human Bioelectric claims: it delivers well regulated current at 1, 1.5, or 2 mA.  If you are shopping for a tDCS device, the Cognitive Kit deserves consideration.


foc.us tDCS Headset Battery Replacement

I have a foc.us tDCS headset that was becoming unusable due to a failing battery.  I decided to replace the battery myself rather that take the time and effort to return it to foc.us for repair.  I thought you might want to see what is involved in battery replacement.  It’s not a job for a novice – good soldering skill (and good vision) is required.  If you don’t want to tackle the job yourself, a local battery replacement shop might be able to do it as they often do soldering work.

The battery in the foc.us headset is a small 3.7V, 150 mAh lithium polymer type (model 041230) and like any battery is prone to eventually fail. It is available from a number of sources – including EBay where I purchased mine for $3. By the way a single AA alkaline battery has a capacity of about 2,000 mAh – thus explaining the need to charge the foc.us headset fairly often.

To replace the battery, you must remove the back cover which is held in place by two small torx-style screws.  If you don’t have a small torx drive around, you may find a small flat-blade screwdriver will suffice. Once the screws are removed, gently bend the headband back and the cover can be lifted away. Inside you will find a small circuit board, the lithium polymer battery, and very thin, delicate wires.  Use great care as you work to avoid breaking a wire.

You will need to gently lift the board off of the plastic pins that position it as the solder connections for the battery are on the underside of the board. You can then turn the board over for desoldering the old battery and soldering the new battery in place.

With the cover removed, the battery, circuit board, and thin connecting wires can be seen.)


(I use a “third hand” to hold the board while I do soldering work. Note the red, positive battery lead is to the outside edge of the board.)

Once the new battery is soldered in place, you can return the circuit board to its alignment posts, place the battery on top of the circuit board, and then put the cover back in place. Be careful not to crimp the fine wires from the battery or those running to the electrode sockets.  Once the cover is back on, reinsert and tighten the two torx screws and you are done!

I suggest you give the headset a good two or three hour charge and it should be ready to go.




Transcranial Direct Current Stimulation (tDCS) is a relatively new technology for treating illnesses like depression, chronic pain (and more) and for enhancing memory, creativity, and various kinds of learning. tDCS is simple, safe (according to current studies), and involves equipment and techniques that are available to almost anyone willing to put in the effort required to learn to use it correctly.

This article is designed to provide a roadmap to successful and safe use of tDCS and so points to a number of references that should be reviewed before any attempt at using tDCS is made. If you will carefully examine the items listed below, you will be much better informed as you make decisions about tDCS and its appropriateness for you and your situation.

1. What is tDCS and How Does it Work?

If you want to understand tDCS and what it is all about, you have to dig a little.

Start with the basics: https://speakwisdom.wordpress.com/2013/11/05/can-a-9-volt-battery-save-a-life-even-yours/

Please watch this video:
Prof. Vince Clark from UC Davis tDCS Summit 2013: https://www.youtube.com/watch?v=dUMUIXNeBRQ

Then read this article (it’s a bit dense, but get what you can):
Transcranial DC Stimulation by Dave Siever, CET: https://www.mindalive.com/1_0/article%2011.pdf

You should also review these safety standards:
tDCS Safety Standards: https://speakwisdom.wordpress.com/2013/10/31/diy-tdcs-code-of-safety/

2. Pick a tDCS Device

You have two choices – either build your own tDCS device or buy a commercial unit.

Build it Yourself


A Simple tDCS Design: https://speakwisdom.wordpress.com/2013/04/02/a-very-simple-current-regulated-tdcs-device/

Or a little more sophisticated device: https://speakwisdom.wordpress.com/2013/02/10/user-built-tdcs-research-device/

Buy a tDCS Device

Very Simple, Inexpensive: www.tdcs-kit.com (review at http://www.speakwisdom.com )

Also simple and inexpensive: http://thebrainstimulator.net/

The foc.us headset is sophisticated and capable: www.foc.us (I have a series of review articles on the foc.us headset at http://www.speakwisdom.com.)


Another very capable tDCS Device: www.trans-cranial.com

The ActivaDose II is very popular. Technically it is an iontophoresis device but can be used for tDCS: http://www.scriphessco.com/products/activa-activadose-ii-iontophoresis-device/


Look carefully at the electrodes that are (or are not) supplied with the tDCS device you purchase. The foc.us headset, for example, includes electrode sponges and is ready to go. Other suppliers provide stick-on electrodes which are generally not preferred. Most tDCS users and researchers have adopted reusable 3×3 sponge electrodes as a starting point. Amrex is a popular brand and is sold widely (including on Amazon.com). The Amrex sponges use a “banana” plug for connection. As such, you may need an adapter to go from your tDCS device to the Amrex sponges. Most medical suppliers carry adapters (www.scriphessco.com for example) or your tDCS device supplier may have them.



As already mentioned, tDCS can be used to treat an assortment of illnesses or can be used to speed learning, improve memory, enhance creativity and more. Check these links for information on the “montage” that best suits your needs.

General Electrode Placement: http://www.jove.com/video/2744/electrode-positioning-montage-transcranial-direct-current

General Electrode Placements for learning, memory, depression, savant learning, and chronic pain: https://speakwisdom.wordpress.com/2013/08/31/the-foc-us-tdcs-headset-review-part-4-electrode-placements/

Depression: https://speakwisdom.wordpress.com/2012/12/06/area-25-is-way-more-important-than-area-51/

Depression: https://speakwisdom.wordpress.com/2013/03/23/4-inthe-youtube-series-treating-depression-with-tdcs/

Researchers generally start with a treatment time of 20 minutes once per day for up to five days per week. A current level of 1 mA is suggested while you adapt to the scalp tingle that tDCS may create. 2 mA is generally too high for beginners and can cause considerable discomfort.

Depression Montage


tDCS is a new and developing area of research. You should use due caution when attempting anything related to tDCS. Better, seek out a medical professional for tDCS guidance and assistance. In Atlanta, www.transcranialbrainstimulation.com is a great resource. You should also monitor multiple tDCS information resources such as www.pubmed.gov (search for tDCS), www.diytdcs.com, www.reddit.com/r/tDCS/ , and Google.

I hope you find the information contained in this article useful and will visit all of the postings I have on http://www.speakwisdom.com.






Yea! The new app for the foc.us tDCS headset has arrived!

After a long, long wait, we finally have a working iOS app to control the foc.us tDCS headset.  While still needing some polish, the app released in January of 2014 gets the job done, allowing control of current, duration and treatment type.

(foc.us app, ver. 2)

To get started, you need an iPhone 4s or later or and iPad 3 or later using iOS 7.  Given those conditions, go to the App Store, search for foc.us and you should have no trouble locating and installing the app.  Then the fun begins!

First – be aware that though this is version 2.0 of the foc.us app, think of it as a 0.99 version. It works, but has much polish and stability to be added yet.  You will struggle with it a bit, but once you get the hang of it, you will find it usable in accessing the features of the foc.us headset. As foc.us adds some polish, this should become the app we’ve all been waiting for!

Getting Connected

Make sure your foc.us headset is charged and ready to go and that Bluetooth is enabled on your iOS device.

To Connect:

  1. Start the foc.us app
  2. Place your headset in “Ready” mode by touching the touch-button for three or four seconds.  It should buzz and the blue foc.us logo should blink.
  3. Touch “Bluetooth” at the bottom of the app screen.  The headset should show in the list of available Bluetooth devices as “foc.us gamer”.  Touch “Connect”. Note – if you take too long, the headset may drop out of “Ready” mode.

(App and headset connected)

  1. Touch the “Current” circle and move the slider to the desired current level.  If you are new at all of this, I suggest 1.0 mA. Touch “Change” to confirm.

(Setting the current level in the app)

  1. Touch the “Duration” circle and move the slider as desired.  Normally, tDCS sessions are 20 minutes (in research anyway.) Touch “Change” to confirm.
  2. Touch “Mode”.  Unless you have a specific research reason to do otherwise, I’d pick “Continuous” – that is tDCS.

(Pick Continuous for tDCS)

Once the above selections are made, the tDCS session should start immediately.

If your tDCS session does NOT start immediately, the app and your headset have probably lost contact with each other (even though the Bluetooth screen shows otherwise). I suggest closing the foc.us app (double-click home on your iOS device, and flick the foc.us app UP to close it).  START OVER at step 1 above.

During the tDCS session, the “Duration” will count down minute by minute.  At the end of the session there is a brief “buzz” from the headset to let you know the session is complete.

Duration counts down as session progresses)


  1. The app and the headset seem to lose sync with each other if you delay too long in making selections, cancel a session, or do much other than the steps I show above. (Remember it’s really a 0.99 release.)
  2. The duration reads “00” during the last 59 seconds of a session.

Update to my Free Guide to using the foc.us headset

I’ll be adding these instructions and more to my free guide in the next few days. I’d appreciate any input you have as the objective is to help headset users get the most from the product. The button to download the free guide is on the right side of my main blog page.

Not in the Box: The SpeakWisdom Guide to Using the foc.us tDCS Headset

If you own or plan to buy a foc.us tDCS headset, you may be interested in the guide to using the headset that I have posted.  The guide is an excellent walk-through of basic use and setup of this excellent product.  Whether your interested in improving memory, learning, performance on games, or relief from depression or chronic pain, tDCS may be right for you.  The foc.us headset provides a very capable, affordable way to give tDCS a try.


See the link on the right side of the main page of www.speakwisdom.com for your FREE copy of the guide.

I invite your comments and suggestions on the guide.



Thoughts on the Use of tDCS in Education Settings

Why the Interest in tDCS?

Research studies and anecdotal evidence show that tDCS, a simple and safe way to stimulate the brain, does have the ability to enhance memory, speed learning, improve physical skill, and enhance creativity.  There are now well over 1,000 published studies of tDCS with more underway and research participation of institutions ranging from Harvard Medical, MIT, Emory University, to the University of Alabama and dozens more.

(tDCS headset. http://www.foc.us)

Already, high-school and college students are catching on to just what tDCS may do for them.  There are many YouTube and blog posts from and by students discussing their experience with tDCS and others asking for help in setting up and using a tDCS device.  Some indicate substantial improvement in their performance with tDCS. As tDCS devices become more accessible and word of it continues to spread through popular press and internet resources (NYT, Nature, Scientific American and many others have already published tDCS articles), educators can eventually expect to be confronted with some significant ethical and policy questions.

While it’s difficult to pin-down an exact percentage improvement students see in their work, (more studies are required), students use words like “significant”, “substantial”, and “surprising” in their comments. As time goes on, not only will more students demand access to tDCS, it is likely that parents, seeking greater success for their children, will encourage its use.

How Might tDCS Be Used by Students

  • During study for tests – including high-stakes (SAT, etc.)
  • Learning lists of material (names, dates, places, events, etc.)
  • Learning new languages (spoken and written)
  • Improving athletic skill
  • Enhancing creativity in writing, art, film production, etc.
  • To reduce or eliminate depression (a common problem in student populations)

Ethical Issues

Educators must face the reality that certain students will “brain boost” using tDCS and by doing so, improve their classroom performance as well as on assorted tests that are common in education settings. Even “high-stakes” test outcome could be positively influenced for students making proper use of tDCS. Student athletes may use tDCS to improve their performance on the tennis court or football field.

  • If a student using tDCS for study can perform 10% better on an SAT test than an equally talented student who does not possess a tDCS device, is there a fairness or ethical issue?
  • If a student has a learning disability and through the use of tDCS is able to perform at “non-disability” levels, is there a fairness or ethical issue?
  • Will we now enter a new era of “haves and have not’s” in K-12 and higher-education learning?
  • Will students from middle-class and above families, able to afford a device and related training, take advantage of it while lower income, less advantaged students will go without?

If tDCS, well used, can improve test scores, is that not ultimately going to be very significant in the lives of some students?

(George Mason University)

Policy Questions

If tDCS is going to play some role in the lives of K-12 and higher ed students in the coming years, then perhaps it’s time to begin creating policy to address tDCS – including:

  1. Will tDCS use be permitted (even though it will be impossible to regulate home use)?
  2. Will students be trained in proper tDCS use in school? (or after school)
  3. Will schools provide tDCS devices for students when the family cannot afford it?
  4. Will schools encourage tDCS as a means to improve test scores?
  5. Will school clinics offer tDCS treatments for those suffering with depression (rather than medicate them?)
  6. Will legal liability issues limit the ability of schools to responsibly encourage and direct the use of tDCS in education settings?

tDCS is a wonderful thing! It has the potential to help the human condition on so many levels – from depression to Parkinson’s disease, with learning enhancements thrown in as a bonus. How will we, as educators, respond to this fascinating new capability – which students have already discovered?

Let the dialog begin!

Contact me via brent@speakwisdom.com

For more information on tDCS see www.speakwisdom.com, http://www.diytdcs.com, http://www.transcranialbrainstimulation.com, http://www.pubmed.gov, and Google!

A $7 Usability Improvement for the tDCS-Kit.com Device

I recently reviewed the tDCS-Kit.com devices and found them to be useful but “bare-bones”.  For about $40 you get a current regulated tDCS device that puts out a max of about 2 mA. ( See https://speakwisdom.wordpress.com/2013/11/03/product-review-tdcs-kit-com-tdcs-devices/ ) While I’m not a fan of the USB version, the 9-volt battery version deserves consideration. Being “bare-bones”, the device is a bit harsh on start-up and shutdown and offers no control of the current delivered other than the 2 mA limit.

I constantly receive emails and messages from folks from all over the world complaining that they cannot afford the $250 (or more) the more sophisticated tDCS devices cost. Yet they are desperate for help with depression, chronic pain, etc.  So the price of the tDCS-kit.com device is attractive – it provides a serviceable tDCS device at a very low cost.

(tDCS-Kit.com Device)

With a very simple modification, the tDCS-kit.com device can have current control! That means you can start and end a tDCS session by ramping current  up and down in a comfortable way – and limiting current at a desired level (say 1 or 1.5 mA.)

Here is what you need:
1. 5 k-Ohm linear potentiometer RS part 271-1714 $3.49
1. Project box RS part 270-1801 $3.49
1. Knob from your junk box or other source

You also need the ability (or have a friend) who can do some basic soldering.

Simply put, the potentiometer will be connected ACROSS the anode and cathode lead from the tDCS-kit.com device. It will act as an adjustable alternate pathway for current so that not all of the  2 mA from the tDCS device will pass through your head. Along the way, you may want to replace the “pin” style connectors with alligator clips (my preference) or banana plugs.

Adjustable current for the tDCS-kit device
(Simple diagram of the mod to the the tDCS-Kit.com device.)

Inside Current Control for tDCS-Kit device
(I put the potentiometer in a little project box. Note that I clipped the pin connectors off and soldered the red-striped lead to the center of the potentiometer.  The red anode lead to the electrode also goes there. The black cathode leads are soldered to the bottom terminal of the potentiometer.)

Current control box for tDCS-kit device
(Complete! tDCS-Kit module is at the left. Leads to electrodes appear at the right.)

May I suggest you also spend a little money and buy a digital multi-meter (many for $10 or less.) You will need that to monitor the current level you are using for your tDCS session. The multi-meter is set to read current and is placed in series with the red (anode) lead and connects to that electrode. With the modification shown above, you can vary current up to the max of 2 mA that the device will deliver.

Warning: Disconnect the battery when not using the device as there will always be a load present.

I think you will find this simple modification makes the tDCS-Kit.com device far more versatile and comfortable to use.

As with any DIY tDCS project, you are responsible for your own actions and safety. If you are not sure what you are doing STOP and get help from a professional and/or read, read, read about tDCS.

Can a 9 Volt Battery Save A Life – Even Yours?


A 9 Volt Battery???

It’s becoming very clear that persons with serious brain related issues can, in many cases, be very effectively treated with the simple application of an extremely low current to the scalp, sourced from a common battery! Nothing painful, exotic, complicated, or dangerous is involved. Yes, transcranial direct current stimulation (tDCS) can be used to treat depression, chronic pain, and is being researched as an aid for Parkinson’s and Alzheimer’s patients. But TDCS has also been shown to be an effective way to speed learning, ease memorization, and enhance creativity. As an example of how far ranging tDCS use is, the US Air Force and Army have apparently been using tDCS techniques to improve cognitive capabilities for years!

(Scientific American)

I’ve been completely fascinated by tDCS since I first learned of it. What other technology is so simple yet has the potential to help so many – whether it be to treat depression, chronic pain, or just dramatically improve the ability to learn or memorize almost anything. What else does all of that with almost no risk or side-effects? Why this isn’t the lead story on the evening news and your local paper is hard to explain.

Think this is all hocus-pocus? Many big name research institutions around the world are now involved in tDCS including MIT, Harvard Medical School, Emory University, University of Michigan, the Spaulding Rehabilitation Hospital,  Massachusetts General Hospital, University Medicine Berlin, The City College of New York and many more. A quick look at http://www.pubmed.gov will reveal that over 900 studies of tDCS have now been published!

What is the treatment?

tDCS basically involves using a tiny amount of energy from a battery applied in particular locations on the scalp, depending on the effect desired. A one or two milliamp ( 0.001 amp) direct current is applied via saline-wetted sponges to two points on the head. For example, for depression the negative lead is placed just above the right eye on the forehead and the positive lead goes high on the left-forehead.) For depression, typical treatment lasts about 20 minutes once a day for about 30 days and the person receiving the treatment feels nothing other than a slight tingle. Treatment can easily done at home. That’s it. No expensive medications with unpredictable results and terrible side effects. It works! Wow! Big pharma is not going to be happy about this!

tDCS treatment hardware is so simple that people (sometimes desperate for help and at the end of their rope) are building their own tDCS treatment systems (about $50 in parts at Radio Shack will do! Instructions are on the web.)

(An example tDCS device built by the author)

While assembled tDCS equipment sold by vendors in the US normally requires a prescription (raising the price to $300 or more), the safety record of tDCS has caused the FDA and suppliers to “look the other way” allowing a number of vendors to now begin offering tDCS equipment directly to individuals. For example, a company by the name of foc.us has recently started shipping a feature laden tDCS headset which sells for about $250.  


There are doctors and clinics now offering tDCS services. One of the better known is in Atlanta – see http://www.transcranialbrainstimulation.com/ Here’s a quote from the Atlanta clinic website, “Transcranial Direct Current Stimulation (tDCS) is a safe, non-invasive therapy for treatment-resistant neurologic, psychiatric and chronic pain disorders. You can increase memory and learning with tDCS, too. Effective, easy-to-do, inexpensive and without side effects, tDCS can be done in the outpatient clinic or, for the appropriate patient, in the home which provides obvious advantages. “

So, Can a 9 Volt Battery Save a Life – Even Yours?

The Centers for Disease Control reports that about 10% of Americans are clinically depressed and either on medication or in need of it.  Also, about 40,000 people per year commit suicide in the US! This huge depression/suicide problem is not being effectively addressed because many who need treatment will not seek it out.  Why? There are several possible reasons including the stigma of depression and its treatment, lack of access to appropriate care, the high cost of treatment and medications, etc. tDCS is inexpensive, simple, side-effect free, and shown to have positive effect in many scientific studies. In my opinion, It should be in the “tool kit” of every doctor and mental health professional.

I’ll close for now and provide you with some links to investigate. tDCS looks to be a bombshell that could literally transform the lives of many, many people. It probably deserves your awareness!

To get you started: 

I have a large number of tDCS related articles and links on my website:


General Interest Wikipedia Article:


tDCS – Scientific American and the Air Force:


General Interest Article with Many References


British Journal of Psychiatry:



Interesting Video and Text about Electrode Positioning:


Atlanta Doctor Providing tDCS Services:


tDCS Headset:


Links to more tDCS information