Gamers blindly navigate a digital maze with input only from brain stimulation

In a new experiment at the University of Washington, test subjects navigated a virtual maze without seeing it. The only input they had were cues delivered in the form of magnetic zaps to the backs of their heads, stimulating particular regions of their brains. From UW Today:

The subjects had to navigate 21 different mazes, with two choices to move forward or down based on whether they sensed a visual stimulation artifact called a phosphene, which are perceived as blobs or bars of light. To signal which direction to move, the researchers generated a phosphene through transcranial magnetic stimulation, a well-known technique that uses a magnetic coil placed near the skull to directly and noninvasively stimulate a specific area of the brain.

“The way virtual reality is done these days is through displays, headsets and goggles, but ultimately your brain is what creates your reality,” said senior author Rajesh Rao, UW professor of Computer Science & Engineering and director of the Center for Sensorimotor Neural Engineering.

“The fundamental question we wanted to answer was: Can the brain make use of artificial information that it’s never seen before that is delivered directly to the brain to navigate a virtual world or do useful tasks without other sensory input? And the answer is yes.”

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Zapping the brain with magnetic pulses boosts libido

In a curious study, researchers at the University of California, Los Angeles showed that transcranial magnetic stimulation (TMS) -- altering brain activity by zapping specific regions with magnetic pulses -- can apparently increase people's libido, at least briefly. Neuroscientist Nicole Prause and her colleagues targeted the left dorsolateral prefrontal cortex (at the left temple), a region involved in reward-seeking. New Scientist explains the curious protocol used by the researchers:

...A vibrator was either connected to a sheath that the penis goes in or a small hood that fits over the clitoris. Electrodes on each participant’s head measured the strength of their brain’s alpha waves, which are weaker when people are more sexually aroused.

During the experiment, 20 people were given TMS for about two minutes, designed to either excite or inhibit the dorsolateral prefrontal cortex. Next, each volunteer was taken to a room where the EEG electrodes were placed on their head. They were then left to attach the vibrator themselves.

Finally, each participant carried out a task that involved pressing a button as fast as possible when shapes appeared on a screen. Depending on how quick they were, they were given a genital buzz lasting between half a second and five seconds – but only after a pause.

Their brainwaves were recorded during this waiting period. “They know they’re about to be sexually stimulated, but it hasn’t actually happened yet,” says Prause. It is the closest analogue for measuring desire in the lab, she adds.

As predicted, after excitatory TMS, participants’ alpha waves were weaker – suggesting they were more sexually aroused – than after inhibitory TMS.

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