Could human memories be uploaded and stored -- just like data -- in a computer? Scientists say not now, but in the coming decades it's likely we'll be able to store our memories in a way that allows us to retrieve them later. Long the stuff of science fiction novels, this kind of merger between computer technology and the human brain is being pushed by new findings in neuroscience, as well as advances in computer science and artificial intelligence.
Two new high-profile scientific projects are also giving impetus to this idea. President Obama announced a $1 billion effort in February to map the brain, while the European Union announced it would fund a $1.3 billion effort to build a human brain in a silicon substrate. But before anything so ambitious as uploading ourselves to a computer is possible, neuroscientists say they have to figure how and where our memories exist.
"It's clearly beyond the capabilities of what we have today," said Ted Berger, a neuroscientist at the University of Southern California. "But it's also true that we are starting to see how we could approach replicating the properties of the brain and replicating the properties of particular brains. In a couple of decades, we will have answers to those questions."
Berger and Sam Deadwyler at Wake Forest University are doing experiments in which they are actually inserting memories into the brains of rats by stimulating certain parts of the hippocampus with electrical signals.
"What we can see is there are particular patterns and activity in space and time that are specific to the object," Berger said. "If an animal has to remember a Red Bull can instead of a can of Coke, there's a particular space-time activity that is different. We've been able to find for the first time these memory patterns."
Berger said they have also been able to disable the hippocampus, in effect blocking the memory, and then electronically stimulating certain areas to create a "new" memory.
"We've already shown that the strategy will work in monkeys and in rats," he said. "I do think we can do this in humans."
At the Massachusetts Institute of Technology, Ed Boyden leads the Synthetic Neurobiology Group, which is building new tools to explore the brain.
In recent year, Boyden and his colleagues have found a protein in algae that is able to convert light into electricity. When the protein, called channelrhodopsin, is introduced into certain neurons, it allows them to be triggered by light. The patterns can they be translated into electrical impulses and then mapped – resulting in a computer code of a memory.
By using this light-electricity protein to turn neurons on and off with light, Boyden is hoping to soon make an on-off switch for brain cells, which would be a huge advance to help patients with brain disorders.
"Our past work has been shutting down neurons in the brain," Boyden said. "We could play back activity patterns and see how it responds. You need to do more than add a control, you should be able to read out, to build and map at the molecular level at the brain. We've opened a whole number of fronts on these technologies."
USC's Berger says there's one big obstacle for actually copying and uploading a complete set of human memories. They seem to disappear when they aren't being used.
"We can go to a microchip and say here are a few bytes of memory, we can see them anytime they want," he said. "It's like buying a Sears catalog of memories and you look through these bins and see what's there. But that's not the way it works with humans or animals. When we use the memories, that's when they appear. But when we don't we don't know where they are."