This Brain Prosthesis Could Improve Memory Loss

IRA FLATOW: This is Science Friday. I’m Ira Flatow.

KATHLEEN DAVIS: And I’m SciFri producer Kathleen Davis.

IRA FLATOW: When you hear the word “prosthetic,” you might think of an arm or a leg, right? But what about a prosthetic for your brain? Yeah, your brain. A device that can kind of zap the brain into remembering information better, like for people with memory loss.

Well, there are people working on that. And here to tell us more is a leader in this brain prosthetic research, Dr. Robert Hampson, a neuroscientist at Wake Forest University School of Medicine in Winston-Salem, North Carolina.

Welcome to Science Friday.

ROBERT HAMPSON: Well, thank you, Ira. I’m very happy to be here.

IRA FLATOW: Nice to have you. Let’s start with the basics. Why can’t people with degenerative brain disease or brain injuries remember things? What’s going wrong in the brain?

ROBERT HAMPSON: There are generally two things that go wrong in the brain. One is the ability to recall information. That’s to access a memory that’s already stored. The second thing that goes wrong is the inability to create those memories in the first place. And it’s this latter part that I’ve been working with.

The issue is that when we store memory, we have to create a code for it. We have to lay down a pattern in the brain that says, this is something to be remembered. And in particular, it’s that function which is impaired in people who have memory loss.

IRA FLATOW: You mean the code is bad? It’s not working?

ROBERT HAMPSON: That’s correct– the code is bad. We had the idea to strengthen the code that the brain is creating. A lot of times what we find is that it’s either weak or incomplete.

IRA FLATOW: That’s interesting. So how do you figure out the code?

ROBERT HAMPSON: That goes back to a development by several colleagues of mine. We’ve been working on this for about 20 years. Drs. Ted Berger and Vasilis Marmarelis and Dong Song at University of Southern California came up with some mathematical models of how a particular part of the brain works when it’s creating these codes for memory. That part of the brain is the hippocampus. We used their model to determine what codes are being generated when a subject is actively creating and laying down new memory.

IRA FLATOW: And you published your research that tested the memories of people with the prosthetic. How did you do that?

ROBERT HAMPSON: What we do is to have a subject sitting in front of a computer screen and looking at pictures. We generally show them one picture at a time. And then, after a short delay, we show them eight different pictures and say, OK, touch the one that you just saw.

Then we also ask the patient to say, how familiar are these pictures? Do you recognize it? Do you remember them? And we’re recording from the hippocampus. We’re recording the neural activity while they see the pictures, they make their initial response, and then later when they’re doing the recall and recognition function.

The model is designed to discriminate between those times when the person correctly remembered and those times when they did not correctly remember. They may have said, oh, I recognize this picture, and it’s one they had never seen before. So we first made that distinction. Then we created the mathematical model. And then, as we were testing the patient on some of the instances where they first see a picture, we would turn on stimulation that was based on that model.

So that what was happening is, as the brain was processing the information, we’re saying, OK, let’s take this prediction of the model into a pattern of electrical stimulation that we can apply. Up to half of the trials would get stimulation and half the trials would not. And then we would test it later to say, OK, now, in the recognition phase, which ones were remembered better– the stimulated or the non-stimulated trials?

IRA FLATOW: And what did you find after you stimulated the patient’s brains?

ROBERT HAMPSON: The first time we demonstrated this, we saw about a 35% improvement in how well they did. We’ve also very recently published another study with more patients in which we also looked at whether there were some other factors affecting memory. And we have seen improvements of up to 55%.

IRA FLATOW: Wow. Now, just to be clear, you did not implant this prosthetic in people, correct? They already had this brain implant in them already?

ROBERT HAMPSON: These are epilepsy patients who are undergoing a study to localize their seizures. So they do have electrodes placed in areas where the doctors can monitor their seizure activity. We don’t implant the electrodes. At present, we don’t have a fully implantable memory prosthetic device. We use a number of computers hooked up to those electrodes.

Our initial target will be to see if we can, if not reverse, at least slow down the degradation that is seen with Alzheimer’s disease. So that’s our very first target, is what can we do for patients with Alzheimer’s disease? We also are looking at, will this be effective in cases of traumatic brain injury, stroke, epilepsy of course, Parkinson’s disease, any of the brain conditions in which memory starts to fail?

IRA FLATOW: This whole concept is amazing. Where did you get the idea for a brain prosthetic?

ROBERT HAMPSON: A lot of this stems from about 40 years of research into how the hippocampus actually is involved in memory research. But as far as making this a prosthetic, I’m a big fan of science fiction, and I was heavily inspired by the Six Million Dollar Man. So I like to say that science fiction inspired me to do science, and the science I do is an awful lot like science fiction.

IRA FLATOW: That’s cool. Let’s just wrap up by trying to understand when this might be available for the public. We all hear this stuff. We say, I know somebody who could use this. But we’re talking many years away, aren’t we?

ROBERT HAMPSON: We are, although some of the initial trials will probably start within a year. But it’s like any other development that we say, it’s five years out, it’s 10 years out, it’s 20 years out. I like to think that the first implementations are within five years.

IRA FLATOW: Is that right? And how would you then choose who gets this?

ROBERT HAMPSON: Oh, that is actually a very good question. Number one, these would have to be volunteers. And number two, we would be looking at probably Alzheimer’s patients and those who are just in the early stages of losing their memory. When the memory function gets very bad, we don’t yet know how well this is going to work. But if we can slow down the progress, then those would be the patients we would work with first.

IRA FLATOW: All right. I want to thank you very much for taking the time to be with us today.

ROBERT HAMPSON: And thank you, Ira. Very happy to be here.

IRA FLATOW: Dr. Robert Hampson is a neuroscientist at Wake Forest University School of Medicine in Winston-Salem, North Carolina.

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