University of Washington
researchers have taken a first step in showing how humans can interact with
virtual realities via direct brain stimulation. They described the first
demonstration of humans playing a simple, two-dimensional computer game using
only input from direct brain stimulation -- without relying on any usual
sensory cues from sight, hearing or touch. 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 five test subjects
made the right moves in the mazes 92 percent of the time when they received the
input via direct brain stimulation, compared to 15 percent of the time when
they lacked that guidance.
The simple game demonstrates one
way that novel information from artificial sensors or computer-generated
virtual worlds can be successfully encoded and delivered noninvasively to the
human brain to solve useful tasks. It employs a technology commonly used in
neuroscience to study how the brain works (transcranial magnetic stimulation)
to instead convey actionable information to the brain. The test subjects also
got better at the navigation task over time, suggesting that they were able to
learn to better detect the artificial stimuli. The initial experiment used
binary information to let the game players know whether there was an obstacle
in front of them in the maze. In the real world, even that type of simple input
could help blind or visually impaired individuals navigate. Theoretically, any
of a variety of sensors on a person's body -- from cameras to infrared,
ultrasound, or laser rangefinders -- could convey information about what is
surrounding or approaching the person in the real world to a direct brain
stimulator that gives that person useful input to guide their actions.
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