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 Galvanic Vestibular Stimulation 
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Two Eyed Hopeful

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A couple of my friends and I decided to play with galvanic vestibular stimulation today, which is electrical stimulation of the sensory organs used for balance for the purpose of inducting a feeling of rotation.

The rig we set up was just a couple of gel electrodes from a muscle stimulator, a variable bench power supply, and an ammeter in line to check what current was necessary for the stimulation to occur. We also tried building a constant current regulator using an LM317, but found that it didn't operate at the low amperage necessary for GVS. We found that 1.5mA was the threshold for feeling the effect, 2.25mA was the sweet spot, and anything above 3mA was uncomfortable. We also found that the thresholds vary somewhat per person.

We tried two electrode setups. One with an electrode behind one ear with the other on the back of the neck, and another setup with one electrode behind each ear. The latter setup had a more significant effect.

The feeling of GVS is bizarre. You feel a left or right roll occurring to the point that your vision rolls briefly in that direction until your brain sorts out that you haven't actually moved and that your vestibular system is actually lying to you. You end up leaning anyway, despite knowing that it isn't necessary. In combination with a wide FoV HMD telling your vision that roll is happening as well, the effect would probably be completely convincing. Basic, roll only GVS is probably of limited utility for most first person VR, but it could add an interesting layer of immersion to vehicle simulations (flight, driving, mech!).

For an actual setup, which I may build when I have more time, I'd make a few changes. It would need to be wireless and battery powered, using a boost regulator to reach the necessary voltages (we needed 14-30 V, depending on the person and how well the electrodes were sitting). It would also need real current regulation, using something like an LM334. Ramping up the current slowly rather than immediately may also be useful. The immediate jolt of "I'm about to fall over" may be good in some scenarios, but having control over it would be better. Lastly, the electrodes we used were fairly large. Using smaller electrodes and placing them in specific positions may allow for finer control and possibly also inducing feelings other than roll.


Sun Sep 02, 2012 12:49 am
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That's cool! I've been dying to try this myself, but knowing how mistake-prone I am, I'd rather not fry what's left of my meager quantity of brain cells.

Do you think PWM would work for ramping the signal up and down? Where do you speculate the electrodes need to be placed for a forward/backward/up/down effect? Do you think the technology could become safe for consumer use like headphones have become?


Sun Sep 02, 2012 9:15 am
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Two Eyed Hopeful

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You wouldn't want to use PWM directly, as AC current can have very different effects than DC for nerve stimulation. You could put it through an op amp to smooth it. A simple and safe solution would just be to use a programmable current regulator like an LM334 with a digital potentiometer. This is likely what I will do when I get around to designing a board.

I'm not sure about non-rotational stimulation. I haven't seen any consensus that it is even possible with electrodes placed on the skin.

While GVS is fun to experiment with, I don't see it being used by consumers. To bring skin resistance and resistance variability down, you would need to use actual gelled electrodes. I don't think headphones or goggles with dry contact points would be safe. It would require very high voltages to deal with the high resistance, and moving around would cause huge changes in resistance quickly.

This paper is pretty good at explaining GVS from a practical engineering standpoint, rather than a medical one: http://digitalcommons.calpoly.edu/cgi/v ... ext=theses


Sun Sep 02, 2012 12:58 pm
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Wow! Sounds interesting. Could definitely see use in flight-sims where you can do barrel rolls and things like that.

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Sun Sep 02, 2012 1:12 pm
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I wonder if you have to get the FDA involved to try and sell something like that. I can certainly imagine an extraordinarily difficult process to getting something like this to market. In my day job, I work for a medical device company and you wouldn't believe the red tape involved with getting certification for totally benign devices - much less something as invasive and potentially dangerous (falling damage) as this.


Sun Sep 02, 2012 1:16 pm
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What does it feel like when you do both at once?


Sun Sep 02, 2012 5:52 pm
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PLease be very careful with what you use for a power supply. Batteries would be best, or a linear psu if you use mains. Switch mode supply have dangerous failure modes. Somebody on here tried to tell me it can't happen, but I have seen it with my own eyes. What I thought was a good psu failed, and took my computer with it. It literaly blew some of the chip packages apart, and killed all the devices connected by usb. You don't wan't your brain in the circuit if that happens.

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Sun Sep 02, 2012 6:02 pm
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Two Eyed Hopeful

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bobv5 wrote:
PLease be very careful with what you use for a power supply. Batteries would be best, or a linear psu if you use mains. Switch mode supply have dangerous failure modes. Somebody on here tried to tell me it can't happen, but I have seen it with my own eyes. What I thought was a good psu failed, and took my computer with it. It literaly blew some of the chip packages apart, and killed all the devices connected by usb. You don't wan't your brain in the circuit if that happens.

Very true. I used a linear HP bench power supply.


Sun Sep 02, 2012 6:30 pm
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Two Eyed Hopeful

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zalo wrote:
What does it feel like when you do both at once?

We didn't have enough electrodes to try it, but in theory having both ears at the same polarity against a common electrode placed on the back of the neck gives a pitch feeling.


Sun Sep 02, 2012 6:35 pm
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In UK they sell electrodes that might be suitable in chemist shops, for use with TENS machines.

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Sun Sep 02, 2012 6:45 pm
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One Eyed Hopeful

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I would urge some caution using GVS. I tried a well-calibrated GVS system from Maeda et al siggraph 2005 (http://www.youtube.com/watch?v=guaiDZdsDjI). The first time I tried it, the effect was interesting, but not very strong. The second time I tried it, it made me instantly ill, the closest I have ever come to an emetic incident (i.e. vomiting) in any simulator and I'm not prone to simulator sickness or motion sickness.


Mon Sep 03, 2012 10:32 am
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Two Eyed Hopeful

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bobv5 wrote:
In UK they sell electrodes that might be suitable in chemist shops, for use with TENS machines.

I ordered some proper electrode leads and electrodes, so I'll give it a try eventually.

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I would urge some caution using GVS. I tried a well-calibrated GVS system from Maeda et al siggraph 2005 (http://www.youtube.com/watch?v=guaiDZdsDjI). The first time I tried it, the effect was interesting, but not very strong. The second time I tried it, it made me instantly ill, the closest I have ever come to an emetic incident (i.e. vomiting) in any simulator and I'm not prone to simulator sickness or motion sickness.

Reading the paper I linked earlier, there are some interesting findings towards the end using specific waveforms to induce much stronger feeling without some of the negative side effects. It may be possible to make comfortable GVS, or at least as comfortable as you can get with electrodes stuck to your head.


Tue Sep 04, 2012 10:34 pm
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Two Eyed Hopeful

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edit: this has not been tested it is just theory.

the right way to do Vestibular Stimulation is to use Magnetic nerve stimulation that way you can focus it on the end of the canals before the vestibular nerves conjoin. fast pulse = brain thinking fluid is moving one direction. slower pulse = brain thinks fluid is going other direction.

you can get FULL Vestibular control this way including, sensation of falling, g-force in any direction, or spinning in any direction...
it would be hard as hell to calibrate but when you do... HOLD ON!

again this is just theory from having experienced one of these Magnetic nerve stimulation devices. you see i am an epileptic with two trigger points in my brain one point is in my left cortex and i forget the name of the other spot, well any way after a trip to a specialist
they used the device on my left cortex to make sure that it was located there and man Oh'man it was one of the weirdest things i have ever experienced literally hundreds of words, syllables and sentences went through my mind in the blink of an eye (99% did not make sense) I was intrigued so i looked in to how it worked.

now the inner ear part. in my early life i suffered from chronic earache's sometimes accompanied by vertigo
(inner ear is scared and all lol) well i looked in to that as well and learned a lot about how the vestibular system worked
and is related to equilibrium Gravity and movement.

just do a little research on how the vestibular system works and Magnetic nerve stimulation devices.
you will see what i am saying will work if you can Align Magnetic stimulation device to the nerve's before it reaches the ampulla in each canal BUT well before all the nerves start to combine on there way to the brain.


Last edited by ChrisP on Wed Oct 31, 2012 3:42 pm, edited 1 time in total.



Wed Oct 31, 2012 10:21 am
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Sharp Eyed Eagle!
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Do you have a background with these technologies, Chris? You seem to speak from personal experience.


Wed Oct 31, 2012 11:58 am
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Two Eyed Hopeful

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i have just edited my post to show a little more detail. in regard to background in Magnetic nerve stimulation devices i have experienced a device first-hand and studied how they work for personal satisfaction

it is just theory.


Wed Oct 31, 2012 3:56 pm
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brantlew wrote:
I wonder if you have to get the FDA involved to try and sell something like that. I can certainly imagine an extraordinarily difficult process to getting something like this to market. In my day job, I work for a medical device company and you wouldn't believe the red tape involved with getting certification for totally benign devices - much less something as invasive and potentially dangerous (falling damage) as this.


What sort of benign devices? I know you are probaby limited in what you can say, but is it something to be inserted in whatever hole, urine test, stress ball, video of kittens and puppies? Even a vague idea would be good.

Has any of the DIY guys here tried GVS yet? I have the equipment lying around, but haven't been brave enough to explain it to the GF yet. ("I'm going to connect this to my brain. I need you to stand and watch with your phone in your hand just in case I spaz out and die. I probably won't, but , it is best to be safe...")

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Wed Oct 31, 2012 7:22 pm
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Well, nrp (who started the thread) tried it with some friends, but I don't know of anybody else on the forum who has put anything together.

EDIT: Also, take a video!


Wed Oct 31, 2012 9:57 pm
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I'm not sure of the FDA needs to be involved if it is not a medical device. TENS machines are available pretty cheaply, and those use much larger currents than GVS.


Thu Nov 01, 2012 10:02 am
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Golden Eyed Wiseman! (or woman!)

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Most of those claim that they should only be available for sale to doctors or by prescription, though. They are not stuck to your head, either!


Thu Nov 01, 2012 7:52 pm
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Golden Eyed Wiseman! (or woman!)
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Skimmed through the thread and i happen to have a sicko Tens machine, hooking it up to my head right now! :lol:

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Last edited by Okta on Tue Jan 01, 2013 12:43 am, edited 1 time in total.



Sun Nov 04, 2012 3:49 am
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One Eyed Hopeful

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I found a tutorial with scematics and videos
http://lab.robomotic.com/hardware-stuff ... troduction


Tue Jan 01, 2013 12:29 am
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After looking at some of the videos in your link i just tried with my tens machine. I put one pad on the shoulder and the other on the mastoid bone. No effect but i haven't actually looked into the type of current is required so no surprise. I am a little suspicious that GVS is actually just flexing the muscles in the neck to pull it one way or the other though?...

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Tue Jan 01, 2013 3:57 am
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Golden Eyed Wiseman! (or woman!)

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Definitely not. GVS uses a lot less power than a TENS machine, be careful hooking that up to your head.


Tue Jan 01, 2013 3:56 pm
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Golden Eyed Wiseman! (or woman!)

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Thats rather interesting ChrisP. I've been quite interested in magnetic brain stimulation since I read about that guy with the helmet that gives you trippy/religious experiences by generating electromagnetic fields.

IMHO its obvious that the future of VR lies in brain jacks and stimulation, gloves, treadmills, and goggles etc are just an intermediate thing while we get there.


Mon Jan 14, 2013 7:49 pm
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I would consider being able to simulate g forces to be a major aspect of immersion for anything action based. Actually subjecting people to the g-forces seems... impractical. A method like this to simulate the feeling is exactly what we need.


Tue Jan 15, 2013 4:51 pm
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WiredEarp wrote:
Thats rather interesting ChrisP. I've been quite interested in magnetic brain stimulation since I read about that guy with the helmet that gives you trippy/religious experiences by generating electromagnetic fields.

IMHO its obvious that the future of VR lies in brain jacks and stimulation, gloves, treadmills, and goggles etc are just an intermediate thing while we get there.
Electromagnetic brain stimulation hacking:


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Sun Jan 20, 2013 2:41 pm
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Two Eyed Hopeful

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Just you watch, give it 10-15 years and you will see people experimenting on the vestibular nerves with these things like I mentioned in that previous post.


Tue Jan 22, 2013 10:09 am
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geekmaster wrote:
WiredEarp wrote:
Thats rather interesting ChrisP. I've been quite interested in magnetic brain stimulation since I read about that guy with the helmet that gives you trippy/religious experiences by generating electromagnetic fields.

IMHO its obvious that the future of VR lies in brain jacks and stimulation, gloves, treadmills, and goggles etc are just an intermediate thing while we get there.
Electromagnetic brain stimulation hacking:



I've tried this; if you have a large research university near you with a neuroscience unit, you too can possibly volunteer to be a test subject as these seem quite common now for certain types of experiment on coordination and muscle function. I tried a system that was attempting to impair (successfully) motor coordination. As we were discussing research ideas afterwards, he demonstrated the effect above. You need to know some brain anatomy in order to target the area where the motor control centre (sorry, computer scientist, not neuroscientist so terminology is off), but once localised you can activate muscles. The gentleman who demonstrated on me "hit" the area for the wrist on his first go, but then he had done hundreds of test subjects.


Wed Jan 30, 2013 5:07 pm
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Hey guys,

Reviving this thread to let you know that I've been working on a GVS device for a few weeks now, and making good progress.
It's a computer controlled bipolar binaural GVS device, controlled via Bluetooth.

Here's an album of the progress so far: http://imgur.com/a/HrcrH

Also, I hooked it to F1 2012 telemetry, and well, see for yourself (watch the mAmp meter):


Hope you'll like it :)


Sun Jul 21, 2013 6:00 pm
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That looks pretty cool. I want to try it myself. I may not make a good test subject though because I am always a bit dizzy from inner ear problems I have had for more than 20 years now. It would be cool if a device like this could compensate for my "normal" dizzyness and make it go away.

But for VR, yeah, this looks pretty awesome and we just need to figure out the right signals. Brain hacking at its lowest level.
;)

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Sun Jul 21, 2013 6:43 pm
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So you have a single electrode on each side of your head, and the polarity changes which way you feel you're leaning, the current changes how far?
just be careful, I've read that these also stimulate the pleasure centres of the brain, so it might just increase your video game addictions. ;-)


Mon Jul 22, 2013 10:33 pm
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Any updates on that setup steeve? it looks really interesting. How did it feel racing? the f1 2012 video basically just showed you driving, I'd like to hear about how it actually felt and affected you while you were going round the track. I'd love to feel more of the acceleration etc playing Dirt2/3, with the Rift and g27 already it's immersive, but it would be really cool to actually feel some of it too.


Thu Aug 22, 2013 7:17 pm
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geekmaster wrote:
That looks pretty cool. I want to try it myself. I may not make a good test subject though because I am always a bit dizzy from inner ear problems I have had for more than 20 years now. It would be cool if a device like this could compensate for my "normal" dizzyness and make it go away.

But for VR, yeah, this looks pretty awesome and we just need to figure out the right signals. Brain hacking at its lowest level.
;)


Can't a GVS be used with a gyroscope to correct just that?


Sun Oct 20, 2013 9:47 am
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Wanted to bump this thread as I'm interested in trying to put something together. Anyone have a functional GVS set up?

-Tyler


Sun Oct 27, 2013 4:42 pm
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One Eyed Hopeful

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ChrisP wrote:
Just you watch, give it 10-15 years and you will see people experimenting on the vestibular nerves with these things like I mentioned in that previous post.


Forget about 10-15 years!,

If you can give me resources I'll have them built this year, with first prototype in 3 months.

I'll just throw this prototyping onto the other design contracts. I'm trying to get a load of really good VR kit for my university researchers.


Mon Feb 24, 2014 8:10 am
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Here is some awesome news about GVS from Samsung, a GearVR (or other headset) GVS accessory!
Samsung's new Entrim 4D headphones add movement to VR by tricking your inner ear. You've heard of Galvanic Vestibular Stimulation before, right? Samsung's Gear VR headset provides a great experience for its $99 price point, but it can't match up to some of the incredible stuff you can do with a motion tracking system, like the one available with HTC's Vive Pre. So last night at the SXSW festival in Texas Samsung introduced a new piece of hardware, Entrim 4D headphones, which give the user a sensation of movement by tricking the body with "specific electric messages to a nerve in the ear." Samsung has a super sci-fi name for this technology: Galvanic Vestibular Stimulation or GVS. ... In its press release Samsung describes the headphones method for activating this system in your body, and some potential use cases for the technology. "Electrical signals—like the ones used to help restore balance in stroke patients—are delivered via headphones equipped with electrodes that correspond with movement data input by engineers. Users thus feel as if they are a part of the on-screen action, and can also sense direction and speed of movement. And, when paired with the team’s Drone FPV, which utilizes data from the drone’s motion sensors, they can even feel like they are flying." ... Samsung is hopeful that by matching the sensation of movement in your body to the experience you're seeing on its headset, it will not only enhance the experience, but be able to reduce the headaches and nausea many people experience in VR. The company says Entrim is still in the development phase, so no clues on pricing or availability. But Samsung is offering live demos at SXSW, so stay tuned for our hands on.

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Mon Mar 14, 2016 12:24 pm
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Never thought this technology would go public in such a short period of time just because of the medical side effects it could have.
Don't they need a FDA approval for that?


Wed Mar 16, 2016 5:59 am
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geekmaster wrote:
Here is some awesome news about GVS from Samsung, a GearVR (or other headset) GVS accessory!


As its now in hands of Samsung at-least project will see daylight is assured. May be GVS headphones hit market too. Samsung might have done good R&D and
my instinct is there must be very less and highly controlled power supply involved in device, which do not leave any permanent side effects.

I expect there may be little discomfort *Aftershocks* at initial trials at varying degree depending on user's sensitivity.

Since Samsung already have working prototype and they are going to carry along it at SXSW, we can expect to see Reddit about it soon. May be
some one post experience here too.....

Indeed medical side effects needs consideration.. but Samsung might already have thought this and found some work around, won't they?


Sun Mar 20, 2016 1:11 am
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I don't think Samsung acts in save waters here.
How could you predict how millions of different bodies would behave?
Example, yesterday afternoon, i suddenly became vertigo for no specific reason. And it is still enduring a little bit right now.
It might have come from my back , cause i am struggling with some vertebraes since a long time.
Every body reacts different. Some people get more often headaches some don't.
The human body is an incredible complex machine, therefore it differs from person to person.
Not to mention the people who suffer from depression, psychosis ..... list goes on and on and on.


Sun Mar 20, 2016 4:42 am
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One Eyed Hopeful

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The technique of galvanic vestibular stimulation (GVS) has been used for a long time. The stimulus produces stereotyped automatic postural and ocular responses. The mechanisms underlying these responses are not understood although they are commonly attributed to altered otolith output. Based on animal studies, it seems reasonable to assume that vestibular afferents from the otoliths and semicircular canals are affected similarly by GVS. With this assumption, and anatomical knowledge of the vestibular apparatus, a model is developed to describe the expected responses of vestibular afferents to percutaneous GVS and the physiological implications of this altered sensory signal. Bilateral bipolar GVS, the most commonly used technique, should produce a canal signal consistent with a strong ear-down roll towards the cathodal side, a smaller nose-to-cathode yaw, but no pitch signal. Bilateral bipolar GVS should also produce an otolith signal consistent with tilt towards the cathodal side or a translational acceleration towards the anodal side. The expected responses for other configurations of GVS are also described. The model appears consistent with published data on the ocular and postural responses to GVS, and suggests other testable hypotheses concerning postural, ocular and perceptual responses to GVS.


Wed Apr 06, 2016 12:50 pm
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