Kim Renfro/Tech Insider
Not the only means of going back to the future.
Or do we?
In a way, our brains take us on a journey through time and even space continuously, the neuroscientist David Eagleman explains - and this is something that speaks to the very core of who we are as a species and as individuals.
"We're constantly living unanchored in time," Eagleman, host of the upcoming PBS show "The Brain With David Eagleman," tells Tech Insider.
In other words, in order to live our everyday lives, our minds help us consider what each decision means for our future. It may seem mundane, but it's anything but: We wouldn't be the individuals that we are without our mental capacity to comprehend past and future.
As an example, Eagleman says that in any afternoon, he might have to decide between writing a grant, going to the park with his son, or going grocery shopping.
When choosing between courses of action, we think about what they mean not just for our present desires but also for our future selves. Writing a grant might be boring in the short term but could pay off in the long term. Playing with your child could feel good immediately and also have long-term positive impacts on your life and theirs. And stocking up on groceries may be tiresome, but future you could be rather upset if there's nothing for dinner.
We're "simulating possible futures and evaluating them," Eagleman says. This doesn't just give us the ability to plan for an immediate future, but also to make a ten-year plan for our lives, to embark on writing a novel, or to plan an expedition across Antarctica.
PBS/YouTube
As part of the same process, our brains take us through space too, as we imagine different locations and what it would be like for us to be in a different place. We know that we're "here" now, but we think about how later we'll be at the movies or at a bar with our friends. We use these visualizations of not just time, but also space, to process the world.
We even journey to the past, remembering fond moments or ruminating - sometimes to our own detriment - on past decisions.
This powerful ability to imagine yourself in possible futures and to evaluate the choices you make is "fundamentally right at the center of who we are," says Eagleman.
It's what has driven humanity to explore the world, establish societies, create art, and even reach for an understanding of the stars.
A unique ability
PBS/YouTube
We don't know that no other species does this. Animals engage in some rudimentary forms of planning, can learn and remember, and even feel emotions and grieve for other members of their family groups.
But as far as we can tell, we plan further into the future than all the other creatures on the planet, and we're the best at simulating possibilities, imagining what we could do and where we could be, and making plans based on that information. That's all due to the power of our brains and for better or worse, it's given us the ability to reshape the world.
Eagleman thinks that this ability to mentally travel through space and time could be the key to what human intelligence really is - though he's quick to point out that the exact basis of what in the brain constitutes intelligence is still a mystery. "If you ask three neuroscientists," he says, "you'll get four opinions."
But that's the thing about the brain. We know more than we've ever known about it, and we know that it gives us the incredible abilities that we have as humans, yet we're just scratching the surface in understanding how it works.
Eagleman says that when he walked into his first Society for Neuroscience meeting, "I saw all these high I.Q. people and thought, 'by the time I'm done with grad school, this is all going to be solved ... but it turns out that 20 years later, the big questions that drew me into neuroscience are still there."
"The Brain With David Eagleman" airs Wednesdays from Oct. 14 to Nov. 18, starting tonight, on PBS. Check out the trailer below: