Published in Nature Neuroscience: 77% induction rate with electrodes on the scalp at 40 Hertz

you guys are making a great job! don't give up !
yeah, we all need to know If/How/Why jeffg's device worked with something close to 100% success, or even 70%.
And the 99% LD Luciding claim to provide with the headband are hard to believe (but I hope it will work!)
This being said, all this electricaly induced LD stuff is just at his begining, it needs lots of "try, mystakes, fails, try again..." that that's what you are doing, so don't give up!

Bye the way:
Has anyone heard about "peripheral cortex" Luciding are talking about?

About the current .
No one has the certainty say now what current will be ideal.

Very often is there lack of understanding about current ,there are many "types" of current:

Current from device (without load or standart load )
Current from device in "live" conditions during stimulation
Current density on electrodes
Current density on electrodes (edge effects)
Sensory treeshold current
Pain treeshold current
Phosphenes treeshold current
Shunting (tangental current in skin)
Current density at a cortex level
Radial current in cortex
Tangental current in cortex

*Current level at cortex does not necessarily mean effect strength

Give information about a current from the device without other parameters is quite useless

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Use 2mA (with load head+electrodes) can be OK if elecdrodes are big enought 5x5cm ,25cm2 ,80uA/cm2 current density .Still this answer is very simplefied for instance its largly depend of electrode type and positions for instance if electrodes are close the tnagental current trought skin will be larger and inrease skin fealing.

Quote:

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Originally Posted by ATA

About the current .
No one has the certainty say now what current will be ideal.

Very often is there lack of understanding about current ,there are many "types" of current:

Current from device (without load or standart load )
Current from device in "live" conditions during stimulation
Current density on electrodes
Current density on electrodes (edge effects)
Sensory treeshold current
Pain treeshold current
Phosphenes treeshold current
Shunting (tangental current in skin)
Current density at a cortex level
Radial current in cortex
Tangental current in cortex

*Current level at cortex does not necessarily mean effect strength

Give information about a current from the device without other parameters is quite useless

---
Use 2mA (with load head+electrodes) can be OK if elecdrodes are big enought 5x5cm ,25cm2 ,80uA/cm2 current density .Still this answer is very simplefied for instance its largly depend of electrode type and positions for instance if electrodes are close the tnagental current trought skin will be larger and inrease skin fealing.

---

We could perhaps try to contact with Jeff and ask him if he minds providing all of this data :yeah

I'll test out the 2mA on my leg and go from there. We should have a working prototype by EOD tomorrow. I'll post follow up and comments based on what I learn.

I have contacted Michael (IAm Coder - lucidscribe) and asked for details about for his setup and progress. His answers were quite interesting, so here are the main points (slightly edited):

"I have not heard back from Jeff yet. I have asked him for some guidance on the DV thread.

I had some issues where Lucid Scribe wasn’t turning off the EV 806 and the 15 minutes alarm would wake me up. And then I had some runs where the mA was too high and gave me headaches or too low and didn’t show an effect on the EEG channel. If the device is set at 2mA, my muscles start twitching. At 1.9 or 1.8, it stops, but I can definitely feel and hear a buzz. It gets uncomfortable and starts hurting after a few minutes. Anything under 1mA for a minute is OK. And the next day throughout the day I can hear a buzzing in my head if I listen closely.

I ended up cutting two of the large stick-on electrodes down to size… was running out of real-estate on my forehead.
I use 5 electrodes - 3 for the Zeo and 2 for tACS. I have one electrode above my right eyebrow, one above my left eyebrow and the ground in the center of my forehead just below my hairline. The two tACS electrodes are just above and towards the center of the left and right electrodes. I have also tried placing them to the sides of the electrodes and away from the center / at the temple.
When Jeff shipped the device, the tACS wires were combined with 2 of the Zeo cables through a splitter / merger. But as soon as I connected the tACS cables, the Zeo EEG would pick up a lot of noise, even when it was off and not plugged into the USB power relay.
A big variable in Jeff's situation was that he did it during WBTB.

I haven't had much success with my setup yet, but I haven’t had that many opportunities to try it... need to take a break between runs. And my work schedule has been pretty crazy where I couldn't afford to mess with my sleep. But hopefully this week with Thanksgiving will give me some time.
I will upload to LSDBase as soon as I get another good recording, regardless of lucidity."

Funny just today i read his post and also want to write him :)

I found some more data about EV 806 device
source: http://www.accessdata.fda.gov/cdrh_d...f8/K082514.pdf
The data are from are from FDA but they seem strange to me they do not make any sense.

I suppose device is controlled by voltage of 0-5V and it is multiplied 10x . So max voltage be 50V and in 500Ohm load give 100mA .If it device setup to 2mA it give output voltage only 1V not very good for planned apliacation.

Use current infomarmation from device is useless its needed to measure it with mutimetter with right range in live setup.
Also is important infomation about electrode size.

The values in device are in peak current effective current is only 16% of it in this case (mutimettrer measure effective current)

--------------------------------------------
I look to current mesurment little bit deaper :

current measurement - What value does ammeter or voltmeter measures (RMS, Average or Peak )? - Electrical Engineering Stack Exchange
Measurements of AC magnitude : Basic Ac Theory - Electronics Textbook

My values are in average current it is 0,637 of peak current

"Measure" current from TENS device it be possible only in oscilloscope by reading the voltage of peak anou counting current . Also its need be done in live conditions head do not act as simple resistor.
Read only value of currnet form tens device is totaly useless and mesuring with ammeter is also not very good method.

---------------------------------------

http://www.sayedsaad.com/fundmental/...s/image012.gif

I look to original study for stimulation params :
tACS. Low-intensity sinusoidal alternating current (250 μA peak to peak) was applied through a battery-operated CE-certified stimulator (NeuroConn Stimulator Plus) to induce frequency-specific alterations of the EEG. Specifically, four electrodes (3.5 × 4 cm2, connected pair-wise) were attached to the scalp at positions close to F3 and F4 and over the mastoids close to TP9 and TP10 (Supplementary Fig. 2a–c), resulting in a maximum current density of 18 μA cm–2 at the scalp.

THE DATA ARE IN PEAK TO PEAK values if i unedrstand it right it is 2x than peak value . If i compare it to vaues you mesured in normal mutimetter is 80uA .Electrodes are 3,5*4 = 14 cm2 and are connected to pairs , one pair have 28 cm 2 . The current desity on electrodes is only 9uA/cm2 peak to peak , 4,5uA/cm2 peak , 3,12 uA/cm2 RMS , 2,86uA/cm average . Device have constant current so we dount need know resistance of elelectrodes and head.

This is my current setup:

http://i.imgur.com/SVvKgA7m.jpg

You can see the two trimmed tACS electrodes sticking out of the same holes as the two EEG electrodes on the left. The original size was roughly the size of the spare electrodes that are awaiting their turn in the top-right corner. They are worn pretty much as they are placed here. The middle / ground electrode is positioned in the center of my forehead just below my hairline. The two tACS electrodes slightly lower and to the sides of it. And then the other two EEG electrodes just above my eyebrows.

@SearcherTMR, thanks for getting me back on DV! My machine died and I wasn't able to reset my password as I wasn't receiving the reset password email. I might have missed some PMs as my inbox was full... the last one was from 2014-10-07.

This is how intense it was at 2mA... it got uncomfortable after just a minute:

https://lucidcoder.files.wordpress.c...ng?w=640&h=320

I have now turned it down to 1mA or just below:

https://lsdbase.files.wordpress.com/...ng?w=640&h=320

I have not yet had an LD, but believe that I came close last night... the tACS was supposed to turn off after a minute, but it kept getting turned back on by the EEG because it was stuck in REM. I was subjected to two doses of 8 minutes each when the staging went from REM to Awake and back to REM:

https://lsdbase.files.wordpress.com/...ng?w=640&h=320

I imagine that is what the signature of lucidity would look like, but I can't remember a thing so it doesn't mean much. After that I received a fifteen-minute-long dose of electricity which gave me a headache and woke me up. I had to turn off the EV-806 manually (it beeps when it is on for longer than 15 minutes) and then I disabled the plug-out and went back to sleep. I exported the logs to LSDBase for anyone who wants to take a closer look.

I will update the code to only run for one minute every ten minutes if I am in REM that long.

Thanks for the post

like i wrote i previous post TENS device is not very good for plication is use biphasic rectangular pulses about 200micro seconds not the sinus wave .TENS waveform is designed to stimulate nerve endings in skin this can increase discomfort. I dount found any study that use this type of waveform for brain stimulation is hard to predict effects. Also current infomation from device is almoust useless it cam be compared only to same type of device with same type of elctrodes in same place and still be very unprecize becouse of different head and head-electrode resistance.Best way to figure out actual current is measure peak voltage in oscilloscope.

Can you write size of your electrodes ?
Size by probably similar to my 4cm2 electrodes , if you be making new electrode in future make it circular it reduce edge effect (current spikes in corners of electrode)
I use for similar size of elecdrodes and max 320uA (average current) it is 530uA in peak current , values in your deviceare in paek current . Still is very hard to compare your wavefrom to sinus one.In stimulation i use 55uA/cm2 , output form device 220uA (bouth values in average current) in peak value it is about 350uA.

If we try coparation by effective current my setup give output 250uA efective end yours if you use 4cm2 electrodes and 1mA on the device 160uA effective current but to 500Ohm load in real condition will be probably lower.

Can you export RAW values from EEG ?
Use scoring by sleep stages dont give almoust any usefull data it be better look to RAW signal in Brainbay BrainBay
*update i found CSV on your site i plan to look at it brainbay

The size is 3.8 cm. Thanks for the tip, I might grind off the edges of these. The tENS device is all I have to work with for now.

The CSV doesn't contain the RAW EEG data. I exported to EDF and uploaded that. Let me know if it works for you - the EDF exporter is still relatively new.

Seventh night on stimulation yesterday.
I tried a stronger stimulation signal this time (not barely noticeable but quite uncomfortable).
No lucitidy again, but I was awoken by the stimulation, so I know for sure that it triggered during REM (because I was dreaming, and I remember quite clearly the dream) - confirming my observation that when the app runs the whole night it does a good job - at least for me...
Attachment 7888
Also, when I woke for WBTB, I was also dreaming (I remember some of that dream as well) and the app also indicated correctly that I was in REM.

Regarding Petr's reading and researching of current strength and measurements, my opinion is that the subjective feeling is more important. I would classify the intensity as sub-sensory (as in Dr Voss studies), barely noticeable, comfortable, uncomfortable and painful. I think that this would help more in getting consistency between different devices and setups - as current measurements can be quite problematic...
As for the signal type, as I have already noted (post 193), official studies like dr Vosse's used sinus waves but Jeff (whose results we are basically trying to duplicate) used TENS and EMS devices that produce square signals - and that is what we are doing.
For me, if I continue not getting results, I will also try sine waves using Petr's easy setup.

Unfortunately use subjective fealing for device setup comparation is quite useless and is it a bad idea. If we not measure quality data we dount get in research anywhere.
Setup is best from sub-sensory to barely noticable range if it is uncomfortabale someting is wrong it can be current density, skin preparation , electrodes...
If someone use wrong electrode the fealing can be unconfortable but current can by few hundred % different form normal uncomfortable current.

----------
I look at EEG files from IAmCoder

stimulation:
Wavefrorm is very different than i expected.
Stimulation have gap for 1s every 2,5minutes

stimulation signal from 2014-11-04 file
Attachment 7890
This is definitly not 40Hz signal i have hard time to name it
The "waveform" main cycle is 1s it has 2positive pulses and one longer negtaive one they are repeated in about 7Hz
* signal can looks like very different in reality sampling rate of ZEO is only 123,16Hz and its ampyfiler is probably very oversaturated
* sampling rate value is strange

second file :
sampling rate 126,6Hz is also strange and more strange is it is diffrent from first file

Attachment 7891
this signal look much better porblably becouse EEG amplifiler is not to overstaurated
but still are there are 1s cycles nad also show 7Hz modulation wthout testin signal on oscilloscope is imposible tell how really looks like

signal have very low quality and many artefact to do some good EEG analisis

Quote:

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Originally Posted by ATA

Unfortunately use subjective fealing for device setup comparation is quite useless ... If someone use wrong electrode the fealing can be unconfortable but current can by few hundred % different form normal uncomfortable current.

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Hi,
Technically I agree with you (what you say is correct), but for practical reasons I think that the subjective feeling is quite valuable.
That is because :
1. It is super easy to measure and report
2. Lets you know if you are within safety limits (sup-sensory to comfortable as you said quite correctly)
3. It is consistent for the same experimenter, using the same device over time (that means if I get the same just noticeable signal, I practically get similar signal strength).
4. It can be quite consistent for different users, provided - as you noted - they have similar (gel) electrodes, so, similar feeling most likely will equal a comparable current.
Now, if we need to make a strictly scientific research or publish a paper, of course that would not be enough (although subjective feeling is noted in papers - and as Petr noticed, even Dr Vosse's paper has mistakes regarding accurate current measurements).
So, what I propose, is to use subjective feeling for between-us communication of signal strengths and respective results in a basic - but practical way.
That, of course, is just my opinion.

From luciding :

Our device can make 6 - 80uA by programming it right now.

We have very stable current, for 6uA it's okay without gel. We are testing new electrodes, like I already told, made with carbon cloth.

We will post update soon, as our tests are going well and will be finished this week.

* current values are probably in average crurrent (62% of peak value)

The 2014-11-04 file was definitely over-saturated. The second file has 40 spikes in each second... although the first few aren't very impressive - no idea what I can do about that with the device. Also not sure about that break every 2.5 minutes.

http://i.imgur.com/FXC3w6T.png

I managed to get it to run for one minute with ten minute breaks in-between without waking myself up, and administered over a dozen doses in a new recording that I uploaded with EDF data. I had exceptionally vivid and long dreams again. The mA might have been too low this time, will turn it up a notch and maybe keep it on for two minutes at a time.

Regarding my trial, eighth night with stimulation yesterday.
The device triggered three times but I had the amplitude quite high, so it awoke me every time, no LD again....
As a matter of fact, from my tests, 4 - 5 stimulations awoke me or happened while I was awake and from the rest, some might have missed REM. So, only 1-2 realy failed - so more are needed if I am to conclude that it is useless. Nevertheless, no more trials for now because of my upcoming exams...

Good work on the trials. And good luck with the exams!

Here the Zeo classified from REM to Awake after 30 seconds of tACS, but I remained asleep the whole time:

https://lsdbase.files.wordpress.com/...ng?w=640&h=320

So it looks like it can work from an EEG signature level in theory at least...

Hi guys.
This is the question I just asked on the Luciding FB page.
Maybe you guys have some informations and Ideas about the issue it underlines

"I have a tecnical question about EOG/EEG and Stimulation timing.
I have just learnt that there are two kinds of paradoxal sleep (REM sleep) : Phasic REM and Tonic REM
From what I understood, on Phasic REM the dream is deep, Rapid Eye Movements are noticable (EOG) but external stimulations are barely noticed bye the dreamer within the dream. it is not so easy to wake up the dreamer at this stage.
On Tonic REM, the dream is less deep, there is no Rapid Eye Movements, but external stimulations are easily noticed in the dream, and wake up is easy.
A REM stage consists of several occurrences of these two kinds of REM sleep, I don'k know exactly the sequences.
My question: does your device take these facts in account?"

Edit: I also asked it to the Iwinks staff on their FB;

Arousal thresholds during human tonic and phasic REM sleep
Arousal thresholds during human tonic and phasic REM sleep - ERMIS - 2010 - Journal of Sleep Research - Wiley Online Library

I suppose that stimulation in luciding will begin in phasic-REM becouse is based on EOG and EOG are mainly in phasic-REM. Is hard to say if luciding device can
tell the difference between phasic and tonic REM from its low quality EEG signal but definitly it not doing it right now.

We even dount know lenght of stimulation in luciding.

tACS is not sensory stimulation so situation is very different but effect willl be problay the same risk of awakening will be grateher in tonic REM . This is simplified becouse stimulation have affter effects that can be very different from effects in stimulation in theory even reverse.

Device does not take these facts in account , it is useless now becouse we dount have enought info about tACS effects.

thanx for the link.
What would be also interesting to know is how the Phasic and Tonic phases are sequenced within a REM sleep stage, how long they are, and how is the evolution of these changes during the whole night.
It is not exactly the subject, but it could give understanding about WILD, DEILD and other LD technics, and also how other LD devices are supposed to work with this kind of biphasic REM structure.

inspired by this forum i decided to build my own tACS
i use a XR 8038 functiongenerator to generate the 40Hz square waveform
i use two pregelled Ag/AgCl electrodes ( 10mm) on position Fpz and Fp2
i have to my surprise a light phosphene reaction with a resistor of 180K
next time : interfacing the tACS with my novadreamer

Nice job!

Quote:

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Originally Posted by poolster

next time : interfacing the tACS with my novadreamer

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I was also thinking about connecting my tACS setup to my REM Dreamer (for better REM detection than the DreamZ app) but I simply don't know how ( basically I have an idea, but it's quite complicated). If you come up with a simple solution that will work with REM Dreamer too, please, let us know!

Try to use larger electrodes and better electrode position.Measure current during stimulation.

for the interface with the novadreamer :
remove LED from NOVAdreamer board and replace with a optocoupler 4N27 ( see foto's)
connections 5 and 4 from the optocoupler go with two fine wires to module
setting novadreamer : dial 2
if novadreamer see movement of the eye : relais close and you get a "phosphene cue" for 10 seconds (if C = 10uF),
for easy datalogging :
i use a webcam in combination met a free time lapse program
place LED 1 in front of the webcam
if novadreamer see movement of the eye : LED goes on for 60 sec and captured with the webcam
Now it is time to play....

more foto's ...

@ Poolster

Ref: DIY tACS - NOVADREAMER.PDF

Going from your schematic I notice that the 8038 waveform generator stays on where you switch the OUTPUT of the 8038 via a SINGLE pole relay rather than a dual.

What would happen for example if your body completed the 0v circuit in regard to the (unswitched) +pulse output at pin 9?

I'd have thought maybe a better and a safer option would be to switch the supply input to the 8038 rather than the output, plus a relay switching might put more noise in the signal.

Did you consider using or ever experiment with the sine wave output @ pin 2 as the 8038 is quite versatile.


Ref: tACS module.jpg

I presume that you have isolated the power supply module shown in the photo?

BTW what is your final load current via the electrodes?