Could Facebook one day be Brainbook ? Mark Zuckerberg said in a recent 
Q&A that he predicts people will send thoughts and experiences to 
each other as easily as people text and email today. However, this 
fanciful idea of brain-to-brain communication is still a long ways off, 
neuroscientists say.
 On Tuesday (June 30 2015), in response to a question about the future of Facebook during 
 CEO Zuckerberg replied: "One day, I believe we'll be able to send full 
rich thoughts to each other directly using technology. You'll just be 
able to think of something and your friends will immediately be able to 
experience it too if you'd like. This would be the ultimate 
communication technology."
 Zuckerberg continued, "We used to just share in text, and now we post 
mainly with photos. In the future video will be even more important than
 photos. After that, immersive experiences like VR [virtual reality] 
will become the norm. And after that, we'll have the power to share our 
full sensory and emotional experience with people whenever we'd like."
    
        
    
He is referring to an advanced form of in which people could plug in, similar to a VR headset, perhaps with 
some kind of actual physical connection to the brain itself. Brains 
transmit information between neurons via a combination of electrical and
 chemical signals, and it’s possible even now to see them via electroencephalograms, and implanted electrodes. So theoretically it is
 possible to encode those signals into bits just as we do with digital 
phone signals, and send them to another person for decoding and 
“playback” in another brain.
 
Reading the mind
 From a purely technical standpoint, it's possible to "read" 
 and get a sense of what that person is thinking, said Christopher 
James, professor of biomedical engineering at the University of 
Warwickshire in the U.K. Functional magnetic resonance imaging, 
electrodes attached to the scalp, or implanting electrodes into the 
brain can all work to reveal something about brain activity in 
real-time. But right now the only way anyone knows of to get the 
precision required to pick up thoughts and feelings is with the 
electrodes. Imaging technologies and scalp-mounted electrodes can’t 
resolve areas small enough to know what’s going on at the cellular 
level, and scalp electrodes can only detect relatively "loud" signals 
that get through the skull.
 But reading the signals is only half the battle. Decoding them is 
another matter. There’s no single brain area that governs thoughts of a 
given type; the way a person experiences thinking involves many parts of
 the brain operating simultaneously. Picking up all those signals that 
make up a thought in a real brain would require sticking electrodes into
 lots of different areas.
 "We'd have to eavesdrop in many locations — some of them deep. If we 
did know minutely where to place electrodes there's going to be a heck 
of a lot of them," James told Live Science. "Then we need to make sense 
of those impulses," he added, referring to the electrical signals picked
 up by the electrodes
 With the computing power available today scientists could probably make
 sense of the complex pattern of electrical signals, that is, if they 
knew exactly what those signals meant. However, that's far from clear. A
 person's thoughts are more than the simple sum total of voltages and 
currents. Which impulses come first, and in what pattern, and how 
intense they should be is still a mystery.
 James noted thatwhich is used to treat Parkinson's and epilepsy, involves sending 
simple signals to specific parts of the brain. But even such a 
straightforward treatment doesn’t help every patient, and nobody knows 
why. And thoughts are a far more complex phenomenon than treating 
Parkinson's, he said.
 Andrew Schwartz, a neurobiologist at the University of Pittsburgh, said
 the whole problem with any such concept of brain-to-brain communication
 is that nobody knows
.
 "How would you recognize a thought in the brain if you cannot define 
it?" Schwartz said. "If you replace 'thought' with intention, or 
'intention to act,' then we may be able to progress as there is 
gathering evidence that we can recognize that in brain activity. 
However, this is very rudimentary at this point."
 
Steps to Zuckerberg's vision
 Scientists have conducted several experiments with sending simple bits 
of data from one brain to another. For example, at the University of 
Washington a team demonstrated — a person with electrodes on his head sent brain signals via the 
Internet to the motor cortex of another person in another room. The 
brain information signaled the person receiving the message to move his 
hand and control a video game.
 Starlabs in Barcelona showed that it's possible to send a rudimentary 
 In that case the sender would think of a word, and the receiver would 
have the visual cortex stimulated by a magnetic field as the signal came
 in. The receiver would see flashes and could then interpret the word.
 At Duke University scientists have experimented with motor impulses between rats. They One rat got a reward for hitting one of two levers when a light came 
on, the other had the levers but no light cue. The second rat was able 
to hit the correct lever more often than chance whenever the first rat 
was given the signal to press its lever.
 Neuroscientists have even
;
 That mind-reading method, however, was limited to areas of the brain 
linked to basic visualization and not those areas responsible for higher
 thought.
 James noted that in all these cases the information has been very 
simple, essentially bits of ones and zeros: When a person thinks about 
opening a door, they know what a door is, what a handle is, that the 
hand needs to reach the door handle to open it. That all happens before 
that person gets to moving arms and grabbing the doorknob.
 
Challenges ahead
 Even with those successes — or at least proofs of concept — progressing
 to a technology that could transfer a person's thoughts and feelings to
 another person is still a ways off, said Andrea Stocco, a research 
scientist at the University of Washington who took part in the motor 
cortex experiment. Many brain scientists think similar patterns of 
neural activity should correspond to similar thoughts in different 
people. But beyond that, nobody can predict exactly what patterns might 
be linked to a given set of thoughts. So far scientists can only 
discover these patterns by experimenting
 He added that while the technology is in theory available to record 
impulses in great detail from the brain, in practical terms placing that
 many wires into a brain to "see" that activity is quite risky. "We do 
not currently have the technology to record from enough cells in the 
brain to decode complex thoughts," he said.
 The other problem is an ethical one, James said. An experiment 
involving hundreds of electrodes inserted into a brain isn't something 
any institution would be likely to approve, even with volunteers. He 
noted such experiments with inserted electrodes tend to be done on 
people who already have some kind of problem – epilepsy or Parkinson's 
disease. (The University of Washington and Starlabs experiment didn’t 
involve invasive surgery).Those patients are getting electrodes inserted
 into their brains already. Even then, the data they yield is often 
crude.
 "It's a bit like having a football stadium with a crowd of people, and 
putting a microphone outside the door and trying to pinpoint one 
conversation. The best I can hope for is to get half of them to shout in
 unison."
 And unfortunately, the only way to know whether such a brain-to-brain 
interface is working is to work with a sentient creature — a person. In 
an experiment done on a rat the rat can’t tell us what it is feeling 
except in simple ways like having the rat hit one lever or another. That
 isn’t anything close to what humans experience. And it’s important 
because there’s a very real question of whether such stimulation induces
 experiences (known as qualia) in the rats, said Giulio Ruffini, CEO of 
Starlab, 
 It's also far from clear what the long-term effects on the brain would 
be — scarring from electrodes would be just one problem. "The brain 
doesn't like getting things stuck into it," James said. 
 Schwartz added that motor impulses are one thing — there have been some successes there with ,
 for instance. But that is nothing like the "rich experiences" 
Zuckerberg describes. "There is no scientific data showing that it can 
be extracted from brain activity," James said. "Despite many claims 
about activating particular brain 'circuits,' this is almost all wishful
 thinking and has not been done in any deterministic manner to product a
 perceived experience. We simply haven't done the science yet."
 Stocco, though, was somewhat optimistic about Zuckerberg's vision. "His
 scenario is far, but not unreachable," he said, as the kinds of 
advances necessary are at least imaginable. "We could get there, given 
adequate work and knowledge."