Prosthetic device restores and improves impaired decision-making ability
September 19, 2012
MIMO-based neural prosthetic. Application of MIMO model detects increased “weak code” firing (1) of neurons associated with error trials following cocaine exposure. Output of the MIMO model is then utilized to stimulate (2) other neurons with a “strong code” pattern associated with correct performance. (Credit: Robert E Hampson et al./Journal of Neural Engineering)
Imagine a prosthetic device capable of restoring decision-making in people who have reduced capacity due to brain disease or injury. by simply recording brain signals during correct actions and playing them back.
This may sound like science fiction, but researchers at Wake Forest Baptist Medical Center, the University of Southern California, and the University of Kentucky have proven for the first time that such a device is possible in non-human primates.
One day it will be possible in people, the scientists say.
In essence, the scientists used an electronic prosthetic system to tap into existing circuitry in the prefrontal cortex of the brain at the cellular level and record the firing patterns of multiple neurons in the prefrontal cortex, the part of the brain involved in decision-making.
They then “played” that recording back to the same brain area to electrically stimulate decision-based neural activity. Not only did it restore function, in some cases, it also improved it.
“The prosthetic device is like ‘flipping a switch’ to turn on a decision in real time,” said Sam Deadwyler, Ph.D., professor of physiology and pharmacology at Wake Forest Baptist, and senior author of the study.
In the study, the scientists trained five monkeys to match multiple images on a computer screen until they were correct 70 to 75 percent of the time. First, an image appeared on the screen, which the animals were trained to select using a hand-controlled cursor. The screen then went blank for up to two minutes, followed by the reappearance of two to eight images, including the initial one, on the same screen.
When the monkeys correctly chose the image they were shown first, the electronic prosthetic device recorded the pattern of neural pulses associated with their decision by employing a multi-input multi-output nonlinear (MIMO) mathematical model, developed by researchers at the University of Southern California. In the next phase of the study, a drug known to disrupt cognitive activity, cocaine, was administered to the animals to simulate brain injury.
When the animals repeated the image-selection task, their decision-making ability decreased 13 percent from normal. However, during these “drug sessions,” the MIMO prosthesis detected when the animals were likely to choose the wrong image and played back the previously recorded “correct” neural patterns for the task. According to the study findings, the MIMO device was exceedingly effective in restoring the cocaine-impaired decision-making ability to an improved level of 10 percent above normal, even when the drug was still present and active.
“The basis for why the MIMO prosthesis was effective in improving performance was because we specifically programmed the model to recognize neural patterns that occurred when the animals correctly performed the behavioral task in real time, which is a unique feature of this particular device,” said Robert E. Hampson, Ph.D., associate professor of physiology and pharmacology at Wake Forest Baptist, and lead author of the study.
“Based on the findings of this study, we hope in the future to develop an implantable neuroprosthesis that could help people recover from cognitive deficiencies due to brain injuries,” Hampson said.
Co-authors of the study are: Ioan Opris, Ph.D., and Lucas Santos, Ph.D., Wake Forest Baptist; Greg A. Gerhardt, Ph.D., University of Kentucky; and Dong Song, Ph.D., Vasilis Marmarelis, Ph.D., and Theodore W. Berger, Ph.D., University of Southern California.
The study was supported by the National Institutes of Health grants DA06634, DA023573 and DA026487; by National Science Foundation grant EEC-0310723; and by the Defense Advanced Research Projects Agency (DARPA), contract N66601-09-C-2080 to S.A.D.
Comments (8)
by Glen Lincoln
Whenever I read, “One day it will be possible in people, the scientists say,” in a science article (paragraph 3 in this one) what it actually means is not only is this merely possible, it is inevitable, and likely will be ordinary within an astonishingly short period of time.
by David Ullery
Yet another cyborg machine part. We will merge with our machines.
by Joe
Cool tech!!
by melajara
I’m surprised this article didn’t trigger any comment yet.
I find it very troubling. At once, I thought about internal Pavlovian conditioning or behavioral induction tampering.
This could be used as a more or less subtle weapon agaisnt the still unhacked albeit illusory “free will” of any individual (welcome Clockwork Orange and neo-neuromarketing) .
IMHO, much to discuss here for philosophers or ethicists.
by Bri
I’d say the movie The Manchurian Candidate, or more of the modern remake, than A Clockwork Orange, which was more about depravity in society, and the forces that foster it. The potential for abuse is extremely high. A toltarian state like North Korea could mandate implants at birth, and down load commands as they deem fit. Like all double edge swords, the potential for good is tremendous. This and other brain implants could alter diseased and healthy brains in radical ways. We talk of mental upgrades and transhumanist desires to go beyond what the human brain is capable of. This is clearly a step in that direction. The big question is morals and ethics. Who gets to decide those issues. It’s a sticky wicket. The forces that drive the behaviors of the characters in A Clock Work Orange have been around long before humans evolved. Check out Jane Goodals work with chimps in the wild. Although it escapes most people, as to why these behaviors evolved, they are conserved for very important reasons. They increase evolutionary pressures. They accelerate social development. Those same forces are still at work today and are mirrored in our political thought. Hopefully we will learn our lessons. As it stands now we haven’t changed much from the days we swung from tree branches. Brutes, tyrants, thugs, you name it. They still abound. Very high potential for misuse and abuse.
by Glen Lincoln
My understanding of the article is that this device is successful in creating a clearer, cleaner process of the subject’s own mind, perhaps by filtering out “noise”. (my interpretation). The researchers record and playback the subject’s OWN, best-of, result. I imagine we could do the same, say, in archery, record and store the mind state of bullseyes, then subsequently replay those more ideal mind states as the archer is performing. It’s not able to swap out your own impulses. But let’s just say we could upload new, external mind software; we do this already when we read a book or see a play, but we still have our wits intact, and we don’t act on suggestions or even orders that are criminal. Well, sometimes we do, but we still know right and wrong. Nobody makes us or brainwashes us without our consent.
by GAUSS
“At once, I thought about internal Pavlovian conditioning or behavioral induction tampering.”
I think of those things too, but when encountering any implant technology, especially those focused on the brain. It’s a double-edged sword, to be sure.
by asiwel
Improve/restore “decision-making ability” in a task/context situation? How do the researchers know that “playing back” the recording did not simply “force” the subjects to make the same – presumably “correct” – decision? I thinking of decision-making ability as something that can go one way or another based on an awareness and analysis of “clues” guided by attitudes (predispositions to act) defined in terms of values. The “best” decision is not always the objectively “correct” one. (rather it can be, e.g., the best I can do with what I’ve got in the particular situation at hand.) Does the subject experiencing the playback have any slack here for volition?