I just hacked my brain (2015)

Cool, but LinkedIn is probably the worst place to document this...

Damn, that's really cool.

My concern with doing this with more than a demo setup would be elecrolysis injury due to long-term exposure to direct current. Humans are basically big bags of electrolyte solution, so applying DC for long periods of time results in ions bunching up at the electrodes and all sorts of nasty chemical effects. This is the main danger when children inadvertantly swallow coin cell batteries: it's not actually the heat that causes GI damage (heat generation from a shorted coin cell is minimal), it's the electrolysis-induced chemical burns that result when the battery pumps a few tens of mA through GI tissue.

Is it possible to achieve the same effect using an AC waveform? That would likely be safer since it won't result in polarization.

EDIT: also, I wouldn't do this to myself, at least not with a 9V battery and a couple of pieces of aluminum foil...

Yeah... reading it in further detail, he applies current across his head between the mastoid processes. I thought it was local stimulation between two surface electrodes under the ear. A quick look at the literature shows that the targeted structures are too deep for an approach like that, so they have to go across the head.

Style points for bravery, I guess, but I certainly wouldn't want to pump over a milliamp of direct current right underneath the squishy mass of goo that contains my conscious self. Especially not with an uncontrolled source like a battery - any sort of stimulator really ought to be current limited.

A milliamp is an awful lot, IEC 60601 specifies a 0.1 mA patient leakage current and I'm pretty sure they weren't expecting even that small leakage current to be applied to the head.

It's still cool, but yeah, nobody try this at home.

Going on a tangent but upon reading about vestibular reflexes I recalled something I used to do as a kid:

When in bed, ready to sleep, I could condition myself to believe the bed was tipping over to the side, up to the point where I would have the reflex of grabbing the sheets to keep myself from falling, similar to jolting awake up after falling in a dream.

I wonder if something could be done to manipulate these perceptions without actually zapping the brain.

Incredible that this guy is building is own electrodes and sending electricity to his body, but what you are noticing is that he might, potentially, get a head injury because he was standing!

I'm sure some injuries were to be counted on in this case.