So, after reading this account, I felt compelled to wire up my current-limited power supply at 1mA and ranges from 6-9V using saline-soaked paper towels.
Got some mild phosphenes during the first try by putting the anode too far forward -- although not in my entire visual field like the author, instead just at the top, and the phosphenes stopped once the electrode was securely connected.
OP, what duration do you use? http://www.ncbi.nlm.nih.gov/pubmed/17940759 indicates that "short-term" is <1s and "long-term" is 10m. It's hard to say objectively, but I think after about 1m I can feel increased concentration and wakefulness.
Initially 5 min, increased to 20 min. Phosphenes are not uncommon if the anode is too far forward and if the circuit is intermittent. Ramping the current up and down is a good idea. I would only use a battery powered supply myself. The video http://www.jove.com/video/2744/electrode-positioning-and-mon... mentioned above is excellent, incidentally (wooden acting aside).
Interesting video -- watching it made me realize that my ad-hoc "electrodes" were too small (2x2 cm), explaining the mild skin irritation. I wonder if it's common also to have a temporary, very moderate blurred vision in the right eye (only during stimulation)? It would make sense considering the cathode inhibits depolarization there. I'll keep reading.
Thanks for posting, this has been an interesting experience.
for 1mA 35cm2 50uA/cm2 i use 30 min (L-DLPFC and right orbital)
for 2mA 9cm2 in higher current density work much faster efect is precivable after few second (aplication 3min) bud ther is a problem - skin iritation and is little itchi
(early expediments)
in publication is recomandet current density under 60uA/cm there was much more but still under tishue damge limit
Got some mild phosphenes during the first try by putting the anode too far forward -- although not in my entire visual field like the author, instead just at the top, and the phosphenes stopped once the electrode was securely connected.
OP, what duration do you use? http://www.ncbi.nlm.nih.gov/pubmed/17940759 indicates that "short-term" is <1s and "long-term" is 10m. It's hard to say objectively, but I think after about 1m I can feel increased concentration and wakefulness.