In a world first experiment using non-invasive technology, researchers out of the University of Washington have set up a working brain-to-brain interface that allows one participant to identify what is in the mind of another.
[Image source: University of Washington]
Using a game of question and answer, participants are able to transmit signals over the Internet using only their minds.
Lead author, Assistant Professor Andrea Stocco, said “This is the most complex brain-to-brain experiment, I think, that’s been done to date in humans. It uses conscious experiences through signals that are experienced visually, and it requires two people to collaborate.”
The experiment uses caps connected to electroencephalography (EEG) machines, allowing for the detection of electrical activity in the brain. Participant A, the ‘respondent’, looks at an object on their computer screen while the ‘inquirer’, participant B’s, screen lists potential objects and related questions. The inquirer may then select a yes/no question to send to the respondent.
The means of answering this question is the clever part: the respondent focuses their gaze on one of two lights, each flashing at different frequencies, to indicate a positive or negative response.
Both answers send a signal back to the inquirer through a magnetic coil behind their cap, but only the ‘yes’ answer is detectable. The two responses differ in intensity, with the positive answer stimulating the inquirer’s visual cortex, resulting in a visible flash of light called a ‘phosphene’. The inquirer then knows the respondent answered ‘yes’ to their question and the game continues.
The researchers performed the experiments using a random combination of an equal number of real and control games, using five pairs of participants housed in labs over a kilometre apart. Stocco affirmed, “We took many steps to make sure that people were not cheating.”
The results were significant. The right object was identified in 72 percent of cases in the real games. Inquirer’s guessed correctly only 18 percent of the time in the control games. Researchers put incorrect guesses down to inquirer uncertainty about the appearance of a phosphene.
Co-author of the team’s PLOS ONE paper, Chantel Prat, said “They have to interpret something they’re seeing with their brains. It’s not something they’ve ever seen before. While the flashing lights are signals that we’re putting into the brain, those parts of the brain are doing a million other things at any given time too.”
Future work for the team includes the transmission of brain states, such as sending signals from a focused student to a student with attention difficulties. Prat clarified, “Imagine having someone with ADHD and a neurotypical student. When the non-ADHD student is paying attention, the ADHD student’s brain gets put into a state of greater attention automatically.”
Traditional methods of communication using technology require the addition of tools to the mix; according to UWToday, these innovations seek to reduce the instruments that separate us. Stocco explained:
“Evolution has spent a colossal amount of time to find ways for us and other animals to take information out of our brains and communicate it to other animals in the forms of behavior, speech and so on. But it requires a translation. We can only communicate part of whatever our brain processes. What we are doing is kind of reversing the process a step at a time by opening up this box and taking signals from the brain and with minimal translation, putting them back in another person’s brain.”