Brain Mapping: From the Basics to Science Fiction
Get ready for the year – or the decade – of the brain.
President Obama recently announced what he called the next “Great American Project”: $100 million, plus private investment, to study what he called “that matter between our ears.”
Much of this work is already happening here in the Bay Area, where neuroscientists are starting small and dreaming big.
Cracking the Code
There's an idea about the brain that you hear a lot: That it’s akin to a language. If you could just figure out the meaning of every letter, you could read it and say – or do – anything.
“Think about what we could do once we do crack this code,” said President Obama in announcing his BRAIN initiative, which he’ll also have to sell to Congress.
“Imagine if no family had to feel helpless watching a loved one disappear behind the mask of Parkinson’s or struggle in the grip of epilepsy. Imagine if we could reverse traumatic brain injury or PTSD for our veterans who are coming home.”
But before any of that can be achieved – even if it can be achieved – we have to understand the brain first.
“The human brain is the most complicated known entity in the universe,” says William Newsome, a Stanford University professor of neurobiology and co-chair of the president’s BRAIN Initiative.
It's Newsome’s job to figure out what this mapping plan is all about.
"The most complex entity in the universe"
He says consider the numbers. There could be close to a hundred billion neurons, or nerve cells, in the human brain. And somewhere in the neighborhood of a thousand trillion connections, zapping little jolts of information back and forth from cell to cell.
Mapping at that level is not going to happen anytime soon, Newsome says.
“We are not going to solve and completely understand the human brain in ten years, or probably not even in 100 years," says Newsome. “It may take us a couple hundred years."
That’s a long time, which is one reason the project has been criticized as too vague.
If the goal of the BRAIN initiative isn't to fully map the brain or to cure a specific disease, what is it? And without a specific goal, how do you decide what kind of research to focus on?
It’s like trying to understand a beach. Do you count the grains of sand? Or study satellite photos of the entire coastline?
Somewhere near the satellite level is the work happening in UC Berkeley psychology professor Jack Gallant’s lab.
A graduate student named James is trying to stay as still as possible inside a functional MRI machine. When James squeezes a ball, the machine beeps steadily.
“It’s the sound of data,” Gallant says.
Mind Reading, Circa 2013
Gallant points to a computer monitor where, every two seconds, another crisp, black and white image of James’ brain refreshes itself.
“Here’s the cortex, the cerebellum back here. This is the brain stem, the thalamus,” Gallant says.
Using the fMRI, Gallant’s lab has been able to record what happens inside subjects’ brains while they watch movies, and then translate those responses into images.
These reconstructed videos are blurry but remarkable, about as close to mind-reading as we get in 2013. Gallant says in theory, this is just the beginning.
“In principle, it’s probably possible to reconstruct any activity in your brain that reflects ongoing conscious brain processes,” he said.
Any conscious thought could, one day, be visible to the outside world: a memory, a dream or your private, internal dialogues.
“We have this little person in our head that talks to us all the time,” says Gallant. “There’s no reason we shouldn’t be able to reconstruct that.”
As amazing – and scary – as this is, Gallant and others are quick to point out that the fMRI is full of limitations. For example, it doesn’t actually show neurons, let alone the connections between them. To be able to easily watch human neurons in action would take a machine that hasn’t been invented yet.
“If we knew what that technology will be, we would invent it today,” Gallant said.
So the BRAIN Initiative is almost certainly going to involve engineers building better machines.
It’ll also involve work that has seemingly very little to do with humans at all. This work is a lot closer to the grain of sand level.
Starting Small, Dreaming Big
John Ngai, director of UC Berkeley’s Helen Wills Neuroscience Institute, studies the olfactory system of – among other things – zebrafish.
Ngai wants to understand what happens in the brain of a zebrafish when it detects pheromones that signal danger. When the fish smell this pheromone, they dive to the bottom of the tank and hide.
Which of the zebra fish’s 100,000 or so neurons are driving this reaction and how?
If Ngai’s lab can figure this out, they’d have a working model for how information in a brain translates into behavior. And eventually not just for zebrafish.
Newsome, the head of the BRAIN Initiative, says fast-forward this line of work a generation or a few, and maybe you're closer to curing diseases like Alzheimer’s. Maybe you’ve even started to answer bigger questions.
Questions like, says Newsome, “why do I make so many mistakes that I know perfectly well are avoidable? Why do I hurt people that I love? Why do I turn left at some corner when I knew perfectly well that I should have turned right? What is it up there inside our head that produce emotions?”
Big questions that will have to start with very small answers.