20 questions brain-to-brain

In a recent study performed by University of Washington researchers, two participants were asked to play the game of “20 Questions” while sitting in rooms almost a mile apart from one another, with no option to talk. In reality, the participants were part of an experiment testing the ability to link two brains directly via the Internet.

This was accomplished through the first experiment that demonstrates direct brain-to-brain contact via signals over the Internet. The head author of the study, Andrea Stocco, also calls it “the most complex brain-to-brain experiment…that’s been done in humans” (1).

In the traditional game of 20 Questions, one person thinks of an object and the other person attempts to guess the identity of that object by asking up to 20 yes-or-no questions. This variation of the game used the same principles but a different means of communication.

In this case, one participant wears a cap connected to an electroencephalography (EEG) machine, which measures and displays electrical action in the brain. This person – called the respondent – then sees an image of an item on the computer (an apple, for instance) that the other participant then tries to identify.

The second participant is given several candidates for this object along with corresponding questions for each one. This person – deemed the inquirer – then selects and asks a question using a computer mouse. The respondent then sees this question and provides the answer – either “yes” or “no” – by looking at a particular LED light mounted on the computer monitor.

This light is one of two forms of communication system between the participants. One light is termed the “no” light (for when the respondent answers “no”), and the other is termed the “yes” light. Each light has a distinct flashing pattern. By looking at one light, the respondent can provide the inquirer with a signal transmitted first through the Internet and finally into a magnetic coil behind the inquirer’s head (1).

When the signal corresponds to the “yes” light, the coil is triggered to stimulate the part of the inquirer’s brain known as the visual cortex, which results in the inquirer seeing something called a “phosphene,” essentially a burst of light that can take the form of a line, wave, or blob (1). By seeing the phosphene, the inquirer knows that the respondent answered, “yes” to the previous question, and can thus continue the game accordingly.

In total, the participants performed 20 rounds of the game: 10 real rounds and 10 control rounds, where a plastic block prevented the magnetic coil from stimulating the visual cortex (1). In 72% of the real games, inquirers arrived at the correct answer. This was only the case in 18% of the control games (1).

The error that constitutes the remaining 28% of the real rounds could have come from a few different sources, such as the inquirer’s uncertainty about seeing the phosphene or the responder’s failure to solely look at one of the two flashing lights (1).

There are several long-term goals for this novel brain-to-brain connection. “Brain tutoring” is one example, where signals from healthy brains are conveyed to injured brains. Another potential goal is the transmission of “brain states.” Chantel Prat, co-author of the study, describes this concept: “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” (1).

The ultimate goal, however, may be to simplify and revolutionize the way we communicate. As Stocco explains, “What we are doing is…taking signals from the brain and with minimal translation, putting them back in another person’s brain” (1).

References:

1. University of Washington. (2015, September 23). Team links two human brains for question-and-answer experiment. ScienceDaily. Retrieved September 26, 2015 from www.sciencedaily.com/releases/2015/09/150923151359.htm