In recent years, the neuroscience world has looked towards brain-to-computer interfaces (BCIs), which allow brains to communicate directly with computers, as the new leader of neurotechnology. But the future may actually lie in the BCI’s lesser known relative: the brain-to-brain interface (BBI). A brain-to-brain interface allows signals from one person's brain to be transmitted through a computer and directly into another person's brain. This process allows the second person's brain to fire in a similar pattern to that of the first.
In a 2014 study, Rajesh Rao and colleagues at the University of Washington transferred movement signals from one participant to the motor area of another participant. Rao used an electroencephalography cap (EEG) on the former, who was called the encoder, and transcranial magnetic stimulation (TMS) apparatus on the latter, who was called the decoder. This allowed the decoder to receive the This caused the decoder to receive brain signals for basic motor functions that the encoder performed--for example, pressing a button.
With the ability to transfer basic motor functions, the University of Washington researchers quickly began developing a way to transfer information. They devised a game of 20 Questions between pairs of participants, in which encoders received an object and could only communicate answers to the decoder’s questions by looking at lights that corresponded to “yes” or “no” responses. The visual response produced in the encoder’s brain was transmitted to the visual areas of the brain of the decoder, who saw flashes of light corresponding to the encoder's response.The BBI allowed the participants to guess the object in 72% of the games, compared to only 18% in control groups.
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