In the new movie "Self/less," which comes out Friday, July 10, a wealthy man dying of cancer (played by Ben Kingsley) cheats death by transferring his consciousness to the body of a younger man (Ryan Reynolds).
Thanks to the help of a secretive doctor and a lot of money, all the procedure requires is going for a short spin in a device that looks like an MRI machine.
Of course, t
mind that originally belonged to the younger body still exists —
which creates some problems for the mind that has now taken up
residence there — but the new body's original mind can be
"suppressed" by taking special pills.
At first glance, this sounds like a pretty sweet deal. But just how far off is this kind of technology? Do we know enough about the brain to even begin to undertake such a procedure?
In recent years, scientists have been making impressive strides toward understanding and manipulating the brain: We have rudimentary technologies for listening in on, and even altering, the mess of complex activity in the three-pound hunk of flesh in our skulls. Scientists have even developed methods for probing the brain using light , a technique that has been used to implant or erase memories in mice.
But as far as transferring the brain's consciousness, a concept scientists still have yet to completely understand or define, we've got a pretty long way to go.
Problem #1: Everybody has a different brain
While the movie makes it seem like we could simply swap memories between two people, it's not that simple: We'd have to also transfer the process our brains use to generate thoughts, Wolfgang Fink, a n euroscientist and roboticist at Caltech and the University of Arizona, told Business Insider.
"The reason why [the "Self/less"-style body-swapping procedure] isn't really possible is that everybody has a different brain," says Fink. "Y ou would have to transfer not just the memories, but the same thought-generating process."
In other words, it comes down to not just what we think, but how we think. Each of us has unique mental hardware, which is why it's likely not possible to simply download your consciousness onto another person, or to a computer, for that matter.
Scientists have developed computer systems modeled on this hardware called a rtificial neural networks, some of which can flip back and forth between two different "mental" states. "That is sort of the closest to what we saw in the movie," Fink said — which is why the main character had to take pills to suppress the other personality coming through. You have these two competing personalities, and we can mimic this competition in software. But a computer may not be able to reproduce you.
Which brings us to our next problem.
Problem #2: We can't just implant memories
For much of its history, neuroscience has been confined to passively studying the brain. But i n recent years, a technique has been developed that allows scientists to actively manipulate its activity using light.
Known as optogenetics, the technique involves injecting a harmless virus (containing DNA found in glowing algae) into neurons in the brain, which causes them to produce a protein that makes the cells active in response to light.
By shining a laser onto these cells, scientists can essentially turn them on or off.
In 2013, scientists at MIT used this method to implant a false memory in the brains of mice. In the study, the researchers placed the animals in a chamber where they received mild foot shocks, creating a fearful memory stored in a brain region called the hippocampus. Then, by shining light on the neurons that encoded the shock memory when the mice were in a different environment, scientists made the mice "remember" getting shocked in the new place even though it hadn't happened.
The same researchers took things a step further in a study this past June, when they activated happy memories in mice that were behaving as if they were depressed. They lost their usual appetite for sugar water, and didn't put up a struggle when picked up by their tails, for example. But when the experimenters shone light on the mice's neurons that activated a memory of a happier time (which they'd found by peering into their brains while allowing them to enjoy some time with female mice) , it "cured" the animals' depression, the researchers said.
Of course, the studies were in mice, not humans. And implanting or altering a simple memory is a long way from transferring the entire set of thoughts and memories from one brain to another.
That brings us to our next problem.
Problem #3: There's an alternative, but it's even trickier
Rather than transferring someone's mind to a different brain, it's more likely we would transplant your entire head to a new body, said Fink.
An Italian neurosurgeon hopes to do just that. Sergio Canavero of Italy’s Turin Advanced Neuromodulation Group announced his plans earlier this year to perform the world's first head transplant as early as 2017. He has already secured a volunteer for the procedure, a Russian man with spinal muscular atrophy, a disease that causes the muscles to waste away and is ultimately fatal.
Canavero's proposed procedure, which he calls the HEad Anatomosis VENture, or “Heaven,” involves finding a brain-dead donor whose body is intact, severing the heads of both the donor and the patient, and attaching the patient's head and spine to the donor's body.
While Fink thinks the head transplant may actually happen on schedule, critics say there are a lot of challenges to overcome.
For one thing, the new body's immune system could reject the head, just as your body can reject a transplanted organ.
In addition, once the patient's spinal cord is severed and attached to the donor body, the body may end up paralyzed. Canavero has claimed he can get around this problem by using a very sharp knife to make a clean cut that would allow remaining nerve fibers to repair the incision, but this has yet to be demonstrated. (In the past, s cientists have performed head transplants with monkeys, but the animals only lived for a few days.)
Even if the procedure were technically possible, it brings up a host of ethical and philosophical issues. Should you be able to inhabit another person's body? Would you still be you? Furthermore, any life-extending technology would undoubtedly be very expensive, so would it be fair that only the rich could have access to it?
For now, it's all just speculation. But you can check it out for yourself on Friday.
Check out the trailer for "Self/less" on YouTube :