7 Mind-Bending Mysteries That Neuroscientists Are on the Verge of Solving

This partner story is part of BrainMic, a collaboration with GE to share the latest advances in brain research and technology.

At one point or another, whether during a showing of The Matrix or sitting in a freshman existentialism seminar, we've all pondered life's eternal questions: Why do we dream? Are we just living in a computer simulation? Do you see the same blue that I see? 

Usually we come to the same conclusion: We have no idea, and we never will.

But it turns out that brain scientists like to get just as meta as we do, and unlike us, they have the tools to answer these questions. Brain-mapping enterprises, such as the Human Connectome Project and the White House BRAIN Initiative, are simulating a model of the whole human brain and the roughly 86 billion neurons firing inside it. Excavating the brain has allowed scientists to delve into the big-picture ideas that we've all spent some time pondering. And with many, they're making great headway.

Here are seven of life's eternal mysteries that brain scientists are figuring out: 

1. Whether we have free will

Credit: TED Talk via YouTube

You're rushing to work in the rain and see a puddle covering the sidewalk in front of you. It looks shallow enough to walk through. But just when you're about to step on in, you realize the puddle is deceptively deep, so you leap across to stay dry. Spontaneous decision, right?

Maybe, but cognition experts are at odds. Some scientists believe that what seem like real-time choices are actually predetermined by unconscious neural activity that occurs seconds before decisions play out.

But even if some snap decisions are preordained, plenty of philosophers and scientists insist that free will is alive and well. Personal autonomy, critics of neuroprediction say, exceeds what electroencephalograms can measure. No one should really shout "Free will is an illusion!" from the rooftops until they can use brain signal analysis to augur ethical arguments and emotional breakdowns.

Still, a few scientists are intent on disrupting the free will debate, and arguably are making progress. One MIT neuroscientist is searching for a free will neuron. Neuroscientist and philosopher Sam Harris, among the most famous contemporary deniers of free will, argues that morality and political freedom can exist even if free will doesn't.

2. Why we dream

Credit: Why Do We Dream documentary via YouTube

It's one of our most basic functions, and yet we still don't quite know why our unconscious mind races after we hit the sack.

Despite what Freud thinks, brain experts dispute that dreams are a gateway into the subconscious, or mean much of anything at all. One, Harvard psychiatrist Allan Hobson, thinks our dreams are a byproduct of attempts by one brain region to make sense of biochemical changes and neural impulses originating in another region.

According to another theory, dreaming is the way we purge extra, useless thoughts collected throughout the day. We make so many unnecessary connections and observations that they gunk up our brains. At night, some argue, we need to clear the decks so we're only holding on to what's important.

A few theories also posit that, in one way or another, we dream for the sake of preserving memories. Some psychiatrists see dreams as a place to store short-term memories before we convert them into long-term memories. Other research suggests that dreaming primarily strengthens the initial memory encoding process.

3. Whether time is real

We measure time with clocks based on planetary revolutions, but according to many experts, the way our brains perceive time shapes our sense of reality more than conventional measures of time.

For example, when we're paralyzed by mortal fear, a blink-and-you'll-miss-it accident may seem like slow-motion torture. And there's a cross-cultural phenomenon that suggests time moves faster as people get older. One theory is that, as we get older, the rate at which our brains beat or pulse actually slows down, Duke University neuroscientist Warren Meck told Radiolab. 

Another explanation is that novel childhood experiences seem to take longer in retrospect, which is the gist of neuroscientist David Eagleman's theory of dense memory. Eagleman studies warped perceptions of time through unorthodox experiments, like having people measure time passage while free-falling during an amusement park ride. Volunteers reported their falls lasting more than two times the actual duration.

Absorbing sensory information sparks a chain reaction among neural networks that leaves something like a time stamp on the brain to help us understand the world, according to research. 

4. The line of consciousness

These images show brain networks in two behaviorally similar vegetative patients (left and middle), but one of whom imagined playing tennis (middle panel), alongside a healthy adult (right panel).

Does comatose equal unconscious? How many and what kind of neurons need to fire to produce all those thoughts running through our minds? What constitutes awareness? Scientists, doctors and even philosophers are still trying to figure it out.

For many years, people in persistent vegetative states were thought to lack the capacity for conscious thought. But researchers have discovered that some entirely unresponsive coma patients still have "robust" neural activity.

Cambridge scientists asked vegetative patients to imagine playing tennis and found previously undetected signs of awareness. Their findings, published in October in PLOS Computational Biology in October, build on previous research challenging our understanding of the level of brain functioning necessary for mental awareness.

5. How our thoughts come about

We can implant electrodes in the brain to measure the activity of a single neuron. But we still don't completely understand how neuronal activity, especially on such a small scale, affects thinking and behavior.  

"We know what neurons are, and we know what thoughts are, but we still have almost no idea how to connect the two," said Gary Marcus, a New York University cognitive psychologist and co-editor of the new book The Future of the Brain. "What neuroscience needs, desperately, is a theory of how to connect behavior and the language of cognitive psychology to the dynamics of individual neurons. Until then, we will just have data, not true understanding.

That true understanding is that scientists are working on now.

6. The possibility of inception

Credit: YouTube. Ellen Page's character Ariadne learns to build memories.

We're pretty susceptible to forming false memories. The neural basis of reinventing the past remains murky, but scientists have been working on the Inception-like feat of implanting false memories into the brain.

MIT scientists have successfully implanted false memories into mice brains, and found that the neurological traces of false memories, called engrams, are the same as real memories. 

A cognitive neuroscientist at Northwestern University, Ken Paller, is working on a project to implant false memories into the human brain during sleep, which his lab partially funded through experiment.com.

In a 2013 study, scientists found that people with highly superior autobiographical memory, the closest thing to photographic memory that really exists, are just as prone to memory distortions as anyone else. 

7. Whether we can ever make a computer as strong as the human brain

Credit: Ray Kurzweil TED Talk via YouTube

The general concept of a brain as a computer comes from MIT philosopher Hilary Putnam, who pioneered the computational theory of mind in 1961. Many (perhaps most) neuroscientists will quickly bat down the idea that a computer can ever successfully replicate the human mind in all of its intricacies. But there are some vocal holdouts.

Futurist Ray Kurzweil wrote How to Create a Mind and now works at Google, where he's leading efforts to build software that understands text as well as the human mind can. The software would be less like Siri, who can produce a list of links, and more like something out of Her — a virtual assistant capable of connecting new and old information, and synthesizing original ideas without prompting.

GE Scientists and Mic are partnering to share the latest advances in brain research and technology through BrainMic, a Spotlight Series that explores the universe in our heads, now through December 2014. Click here to read more from this series on BrainMic >>