The document discusses transcranial direct current stimulation (TDCS), a technique that uses weak electrical currents to alter brain activity and potentially improve cognitive functions. It involves placing electrodes with saline-soaked sponges on the head to make specific brain regions more or less active. The founder of OpenStim, Nathan Whitmore, describes how TDCS devices work, noting they are safe and can be used experimentally to enhance skills like math ability. He cautions that effects are mild and transient for most, but some research suggests TDCS may help conditions like depression or improve athletic performance over time with repeated use.

1. ARI
Now I am speaking with Nathan Whitmore who is the founder of open stem and a creator of
Tran’s cranial direct consummation devices. So Nathan thanks so much for talking with me.
NATHAN
No problem it’s good to be here.
ARI
So first of all, let’s tell everybody what TCDS is?
NATHAN
Okay, so TDCS is basically just a neuroscience research technique that involves putting very
small amounts of electric current through the head and what this does is that you can actually
make certain regions of the brain more or less active and this is really exciting because you think
about the brain, the brain is made up of a whole bunch of regions that all interact with each other
and depending on kind of the balance of activity between regions you can predispose people to
different behaviors or improve certain cognitive abilities, so what TDCS allows you to do is alter
how active the brain region is and then in doing so potentially improves some aspects of
cognitive function.
ARI
Okay so now I think that I brought this up in conversation, the image that comes into a lot of
people's head is like people with seizures getting recess and am thinking it’s a shock therapy,
obviously, this is a much lower current.
NATHAN
Yeah and that's what people ask me about too and I explain this to them and actually it’s a lower
current and that the big difference because, what you're doing in electroshock therapy is you are
actually trying to make all the neurons fire at once and that's what makes you have a seizure, a
seizure is actually a whole bunch of your neurons firing at once. TDCS is too weak to actually
make neurons fire, but it just makes them kind of slightly more likely to fire, and what that
means is that you don't destroy the original function of that brain regions when you're doing
TDCS, it still doing what it's supposed to do, but it’s doing it slightly more or slightly less.
ARI
Okay so how do you know and I mean you just walking through how it actually works, like what
does the device looks like, what you're attaching to yourself, how does it really works?

2. NATHAN
Yeah so a TDCS device, most of the once you will get right now will look like just kind of like a
box that will have two wires coming out of it that goes to sponges, well they are actually called
sponge electrons, where I think you will soak them in saltwater and you place them at certain
positions on your head and in the saltwater access kind of an electrical bridge that helps the
electricity get to your skin and where you put down is actually determined by, there is the system
that neuroscientists used to say what and where different brain regions and it is based on
measuring distances across the heads, so it’s called the 10/ 20 system. So typically when you're
doing a TDCS session you would figure out exactly what kind of cognitive ability you are trying
to enhance, you can look at research that said where you had to place the electrodes to do that,
you place the electrodes and secure them with something and then you would usually just for
example turn on dial on the box that would tell at this that a certain amount of current, with a
certain polarity, for a certain amount of time, through this electrodes.
ARI
To me it sounds like there is a lot of variables alright so in terms of you know the settings and
where you place it, is there anyway, is there any system to it?
NATHAN
Is there any system you like?
ARI
I know you say you can adjust the current and the and obviously going to adjust where you place
them, how much does that vary from person to person, what kinds of levels they are in and where
they go?
NATHAN
So that’s actually a good question and that actually gets one of the ways that TDCS is researches
is kind of lacking right now is we right now, we understand kind of what settings are best for
accomplishing a specific thing, but not really very well how that differs by persons so typically if
you're setting all those variables for a session, what I will do would be, look up based on
scientific research of people of collected things, like the current level and the placement to
achieve a specific thing and it's not you don't so much do like tweaking based on the person.
ARI
Okay gotcha, now like what kinds of I am sure they obviously sound like memories of, what are
the specific things that people are going to be doing with TDCS.

3. NATHAN
Yeah I see a lot of people actually talk about depression, there is increasing in pretty good
evidence that is a specific part kind of TDCS where your placing an electrode on the left
prefrontal cortex or over the left prefrontal cortex that intermediate depression, so there's a lot of
people who are interested in that, also a lot of people who are interested in improving their
ability to connect pay attention to things for long periods of time and also improving their
memory or making themselves learn faster, there has been a lot of interesting in the DIY
community about whether there are certain ways that you can use TDCS to speed of learning.
ARI
And now just to go back to what we were saying, this may seem like redundant, but if you put in
one sponge on the left prefrontal cortex, where does the other one go?
NATHAN
So typically when you're stimulating the prefrontal cortex, you put one that would be right over
the prefrontal cortex and the other one would go either above like right above the eye or like
where the eyebrow is on the other side or on the arm or on the other side. We used to think that
putting it right above the eye was kind of a neutral spot, it turned out that it wasn't the case and
actually that when it's placed above the eye, might be stimulating that part of the brain too, so
that's why some people like to put the other one somewhere that's not on the head so that you
don't have to deal with two electrodes having potential effects on the brain.
ARI
So that was why I asked because I have heard about that, you put the other one basically on the
arm, so because of what I was wondering was not like directing the direction of the current
specifically so that doesn’t really have effect on how it works.
NATHAN
Probably not, the current spreads out quite a bit, so it's high beam that's going straight from one
electrode to the other, it is actually quite diffuse, I probably should mention this before but part
of the problem is that when you set up this circuit you have one electrode which is where
electricity is entering the brain and brain tissue under. Electorate becomes more active, but on
your other electrode the tissue under that area becomes less active, so if you can use that to your
advantage, if you're trying to for example: change the balance of activity between two parts of
the brain, but in some cases you don't necessary want to do that and that's when you put one
electrode on the arm or somewhere else.

4. ARI
Gotcha and now you mentioned you can also use these devices to decrease activity and
particularly to the brain, when would you want to do that?
NATHAN
So they are always really interesting studied by the researcher named Alan Snyder and what his
research suggests is that there is an area kind of on the left side kind of between the fore head
and the ear and if you turn that region off, if you suppress it, people show these abilities that are
typically associated with autistic savant like better visual drawing abilities or the ability to count
enormous numbers of objects instantly, so we think that in some cases you can enhance a
cognitive function by inhibiting another region whose job is to kind of put the brakes on that
function.
Another example is I actually had an accident where I had a stimulator set up incorrectly and I
ended up kind of turning off a chunk of my prefrontal cortex and the result of that was what
you'd call actually a flow state where everything suddenly felt very automatic, usually very
fulfilling and I think there's something to that, that if you turn off this part of the brain that is
doing kind of these supervisory things, when you're doing something, it doesn't really need them
and they actually enhance performance when you're doing something that you already know how
to do.
ARI
That's very interesting, I spoke to Steven Connor before and we talk about possible ways of
inducing process and that was one, you can’t just buy these devices, I think most people just
make them.
NATHAN
You can buy them actually, there's a few companies now which are making them that sell them
directly to consumers, but there's also a sizable group of people who make them.
ARI
And it's a fairly simple device right?
NATHAN
Yeah it can be very simple, that complexity goes up depending on how much safety and
reliability you want though.
ARI
Wouldn’t you want a lot?

5. NATHAN
You would think, a lot of people who want a lot of them really cheaply and that does create, that
does create some tension especially when you have devices that are already assembled, some of
the very cheap already assembled ones actually are a little bare bones in the safety department,
but generally the most important thing is that it has something called current regulations, which
means that it will always apply the same amount of current regardless of how much resistance it
is and that's basically what keeps you for it from sending too much electricity through your brain
and turning or burning you are doing other bad things.
ARI
Could you give us one or two example of the companies that make one that you think is good.
NATHAN
There is a company called trans cranial technologies, they make a very good TDCS device, it’s
about $400 I think the last time I checked, so is a little bit expensive but the other option that is,
there are companies that make these things called iontophoresis devices which are not actually
for TDCS, they are actually designed to deliver little packets of medication through the skin, but
they also actually make very effective TDCS devices, so there is a thing called Chattanooga
iontophoresis device and it do pull iontophoresis device, that also are very good, kind of Off-
the-shelf TDCS list.
ARI
That's cool, okay so and then but if you are going to build one yourself that’s relatively safe, how
much money are people looking at to do that?
NATHAN
If you are going to build a good one yourself that kind of have the minimum requirements for
safe, I'd say probably at a minimum year, you're looking at about $40, probably only maybe $10
of that is going to go into the actual electrical components, you can build the elect like most of
the components for very cheap, but the most expensive part if you're trying to build the
components as cheaply as possible is going to be the electrodes and having good-quality
electrode is important because if you're electorate are badly, they can actually burn your skin and
the best kind of electrodes are called sponge electrodes and those tend to run maybe like $20 to
$30 to$40 depending on the kind you get if you want a fancier device you're talking about to
build yourself which would be something like the open standard talking about maybe $50 to
build the device, but that has the advantage of not only is it pretty safe, but it can also do
everything that one of these thousand dollars commercial devices can do, so it’s a good deal.

6. ARI
Yeah so you mentioned burning like what is the other than burning the skin, what are the real
possible side effects or downsides.
NATHAN
Yeah so the side effects are much less exciting than most people think they would be, in some
people who are using TDCS gets headaches when you're using it, few people get fatigue or
insomnia, although that’s actually like we are getting into the just like a couple of preventive
people category, those are really the kind of effects that seem to be intrinsic to using a TDCS
device, but the other thing to keep in mind is that, because TDCS is altering your brain activity
you can alter your brain activity in a way that’s bad using it, so if you like if you look on TDCS
forms you will see occasional reports people doing something new, something that not many
people have done before and it ends up like making them really angry or making them depressed
or like in one case someone was actually using a poorly designed device and he lost
consciousness with it, but the good thing about those reports is that pretty much every time you
hear one of those it's because there was something wrong with either the device or with how the
person was using it and if the person is following the kind of standard accepted guidelines for
how to use TDCS safely, you are really only going to see this very mild transient effects like
headaches.
ARI
Other than accidentally knocking on your PS3, have you ever had a bad experience with TDCS?
NATHAN
I have not actually, that was the closest that I came to a bad experience and that was not really
bad, like I was actually working on a programming problem and it helped me solve that and it
wasn’t until the time and I was like, wait I had the polarity right here, so my experience with
TDCS has been all good, I also do tend to be one of the people who does some of the more
experimental stuff, like off the beat and that pattern a little bit in terms of where I put electrodes
and I haven't had any bad experiences, I think that does speak to it being a pretty safe things in
general.
ARI
So what were some of those unusual uses experimentation you did and what was the result?
NATHAN

7. One of the things that I was interested in for a while was that, I am actually pretty bad at math
which surprises people, because I do neuroscience and computer science but I am and one of the
first thing that I was interested in looking at TDCS to do was improve my math performance and
so the way I was looking at doing that was stimulating the right parietal cortex, which for various
reasons I suspected my right parietal cortex might be a little bit weak, so I started stimulating it
and while doing kind of some basic math arithmetic task, so I actually found there is a significant
improvement on those tasks and also in kind of mental significant improvements in my ability to
do those kind of mental arithmetic tasks and also things involving kind of mental visual
operations, so for instance like recognizing differences between figures or doing mental
rotations.
ARI
Interesting is there any way to use it for like physical improvement like reaction or that's not all
physical reaction time for instance?
NATHAN
Yes it seems like it, I'm not entirely clear on the studies specifically on the reaction time, I don't
know if that’s something they have looked at, one of the very earliest things that TDCS was for
was when people have to learn kind of new motor skills, they found that if you stimulated the
motor cortex it could speed up learning of kind of manual skills, like how to do a complex motor
task. More recently they've actually found that TDCS can in high-performance athletes actually
seems to be able to regulate kind of the systems that control fatigue and actually make peoples
fatigue more slowly, if you do those fake spots or there is even evidence now that can influence
appetite and it might be useful in helping people lose weight, so that is a huge part of it right now
actually is using TDCS to kind of reprogram the brain to then program the body to do something
else.
ARI
And that is amazing and one of the things that I really focus on with my work and with people is
stress reduction, so I only assume that there is probably some benefit from TDCS for stress
management sort of nervous response, but how does the effect lasts when you use it?
NATHAN
The effect most people will say on the average after you do a session of may be like 10 to 20
minutes, the effect will last anywhere from maybe like 90 minutes to 2 1/2 hours is the general
range that you'll see, that's consistent with where you do neuroimaging and you can actually
track, you can see the differences in activity, but on the other hand for instance when you are
using this to treat depression, you can have people going in for one treatment a day and they had
changes, they have improvements in their mood that occur over a long period of time, so it seems

8. like the bulk of the effects occur kind of within 2 1/2 hours, but there can also be some sort of
subtle lingering effects.
ARI
Okay cool, now if somebody wants to try it out, you know what will be the best place to start and
what I guess experiment will be the best thing and one of them where they could sort of see and
be like whoa, this is amazing.
NATHAN
The first place to start I think would be there is a TDCS subgrade which is kind of discussion
forum it’s at www.Reddit.com/art/TDCS. There is a lot of people who talk about TCS on there
and we also have like a big list of frequently asked questions that goes over things that people
commonly ask, like what kind of stimulator should I get, I would advised looking at that if you
are not familiar with electronics, I would advise looking at some very basic stuff about electronic
circuits and Ohm's law talk to people on the form if you're unsure about the electronics in the
neuroscience or if you built the device site.
In terms of our first experiment I would do with that, I would say doing at all stimulation, so
stimulating the left prefrontal cortex with the electrode that inhibits the brain activity, either over
the right eye or on the arm and what we should look for this is one of the placements that we had
the best evidence for and what it seems to do is, it seems to improve short-term memory so you
can do tap that brings instant test how many numbers you can remember in a sequence, do that
before you do the TDCS and afterwards and see if you see difference, in short and its really cool
because you are like am making myself smarter.
ARI
That's awesome anything like that where you can sort of see the immediate result that's a really
good one because, I feel like memory is one of the things that sort of generally failing in society.
NATHAN
That placement is actually, if we don't really have a place where we can like one place where we
can just say kind of unequivocally this is the spot that makes you smarter, but that particular
placement has gotten a lot of research and it seems to benefit a whole lot of cognitive functions,
so if you do know either one do that one.
ARI
Great so now the last question I always like to ask people on the podcast is, what are your top
three personal recommendations for being more effective and in my world that really means
getting more done, you know what, you created this project in the experiment of these devices,
like what are your recommendations for being more effective from anything that you know.

9. NATHAN
In regards to TDCS or just anything.
ARI
Anything that you think that make someone more effective.
NATHAN
So I would go with first of all, diet, making sure that you are having proper nutrition, having
especially kind of the right amount of blood sugar all the time, all the time is extremely
important for making me effective, kind of limiting exogenous input when you're trying to do
something, so for instance setting up email filters so that any given time you're only trying to
deal with the emails that are really important and giving yourself like one part of the day that the
time where that you have to kind of worry about everything that you haven't dealt with, so
instead of having that constantly intruding, you can say okay I'll put all these things off to this
point and then I will deal with that.
ARI
Is that three?
NATHAN
Yeah that’s three.
• Nutrition.
• Filtering.
• Setting aside time to deal with things.
ARI
Gotcha, those are great. So Nathan, I will have links to what we talked about on the show. So
what’s the best place for people to really find out more about you?
NATHAN
The best way to or probably the best way would actually be my reedit profile which is
www.Reddit.com/you/Osnapnathan, it all just kind of have one word, I also have a website that
talks about it has projects that I have worked on or I'm currently working on and that’s
sites.google.com/site/nathanww, again just one phrase.

10. ARI
Well Nathan, thank you so much for your time it’s really nice talking with you and I hope that
this will make people to start trying TDCS.
NATHAN
Safely, I also inspire them to do it safely.
ARI
Absolutely thanks again.
NATHAN
No problem, thanks for taking your time to talk with me.