Transcranial Direct Current Stimulation – or tDCS – is the technique of applying electrodes to the skull and running a small but perceptible current through them. It’s not much current – usually on the order of 1 or 2 mA, but the effect of either increasing or decreasing neural activity has led to some interesting studies. [Theo] over on Instructables wrote a tutorial for making his own tDCS suppy that will supply 2 mA to electrodes placed on the skull for everyone to experiment with.
The basic idea behind tDCS is to put the positive electrode over the part of the brain to be excited or the negative electrode over the part of the brain to be inhibited. This is a well-studied technique that can be used to improve mathematical ability. It’s not electroshock therapy (although that is a valid treatment for depression and schizophrenia) in that a seizure is induced; tDCS just applies a small current to specific areas of the brain to excite or inhibit function.
[Theo]’s device is a simple circuit made of a transistor, resistors, and a few diodes to provide about 2 mA to a pair of electrical contacts. With this circuit and a few gel electrode pads for your head, you too can experiment with direct current stimulation of your brain.
Of course we need to warn you about putting electricity into your head. In any event, here’s a quadcopter / stun gun mashup we made. Don’t do that, either. You might get a takedown request.
[Bruce] sent us another fantastic final project from the ECE4760 class at Cornell. What you see above is an array of 36 near infra red LEDs shining into this young man’s brain for the purpose of spectroscopy. Light bounces back differently based on brain activity (blood flow). For this project, they are mapping their motor cortex and displaying it on a PC using a java app. You can see the entire rig, as well as the readings in the two videos after the break.
When this tip came in, one of our writers,[Jesse Congdon], chimed in as well.
hey I actually used to work in this as an intern, at Upenn. two frequencies of near infrared light are used that both penetrate skin and bone, one bounces off of blood in general and the other bounces off oxygenated blood. Since your brain actually regulates the flow of blood to parts that are in use you can see brain activity by looking at blood flow, but then you also need to see if the brain is actually using that blood, so oxygenation gives you a full picture. The frontal cortex is a nice place to measure cause there is no hair on that portion of the skull, and it gives you emotional responses and the “aha!” moment when you figure out a problem.
One article from way back said the system was going to be used as a lie detector, since when you lie you think about the truth and the lie simoltaneously and show an increase in activity.
It’s tough though to categorize a response since you can’t really establish “base line” activity by turning off the brain
Continue reading “Mapping the motor cortex”
This overly large magnet certainly completes the mad scientist look (for an even crazier look, take a jar of water with red food coloring and place in one large cauliflower, instant brain in a jar).
The base of the magnet is painted foam cut with a makeshift hot-knife; to get the magnet sparking [Macegr] laser etched acrylic with a fractal pattern and embedded LEDs in the ends of the acrylic. An Arduino handles the flashing LEDs and also produces a 60Hz PWM pulse for the spark’s hum. The end result is satisfyingly mad, and while practicing your evil ominous laugh catch a video of the magnet after the jump.
Continue reading “Large magnets spark on Halloween, who knew?”
Our little red-eyed friend can drive this vehicle around with his mind. WITH HIS MIND, MAN!
This is the product of research into adaptive technologies. The process is pretty invasive, implanting neural electrodes in the motor cortex of the brain. The hope is that some day this will be a safe and reliable prospect for returning mobility to paralysis victims.
We found it interesting that the vehicle was trained to react to the rats’ movements. They were allowed to move around a test space under their own power while brain signals were monitored by the electrodes. Video tracking was used to correlate their movements with those signals, and that data is used to command the motors for what the Japanese researchers are calling RatCar.
We can see the possibilities opening up for a mechanized cockroach v. RatCar free-for-all. Something of a battlebots with a live tilt. But we kid, this is actually quite creepy.
[via Neatorama and PopSci]
Reader [Eric] sent us a powerfully informative, yet super simple hack for the MindFlex toy. Don’t worry, it’s not another worthless shock ‘game’, And it’s using an actual interface instead of the built-in LEDs.
With two wires for the serial protocol, and an Arduino, you’ll be able to view “signal strength, attention, meditation, delta, theta, low alpha, high alpha, low beta, high beta, low gamma, high gamma” brainwaves. While it’s not medical grade, it’s a lot more intuitive than previous interfaces.
The original intent was for a system called MentalBlock, but we’re wondering what would you do with brainwave data?
Here’s another video demo of [Eric]’s Besmoke interactive fluid simulation that we covered earlier. It was put together for the BIL Conference last weekend. This time around he’s strapped the iPhone to his head (complying with California’s handsfree laws). To make things interesting, he’s also added OCZ’s Neural Impulse Actuator to provide brainwave input.