Memory response is improved to better than natural levels

"Say hello to my li-ttle friend."

We're not talking about Tony Montana's beloved multifunctional machine gun/grenade launcher.  The "little friend" we are talking about is a futurists wet-dream or cyberethicist's worst nightmare -- a cybernetic implant that could one day improve cognitive function in humans.

I. Learning and Injury

The implant consisted of an electrode prosthesis which attached to two areas of a Rhesus macaque monkey's neural cortex.  Monkeys are closely related to humans and shared a great deal of neural physiology, hence they are ideal for testing of brain activity or studying implants prior to human trials.

The implant showed the ability to not only restore damaged memory function in the monkey test subject -- it actually improved the monkey's memory above the original baseline.

Rhesus macaque
Rhesus macaque monkey [Image Source: Mark Snelson]

The first step was learning.

In this phase monkeys were shown an image and then encourage to move a motion-activated cursor by moving their arms.  If the monkeys selected the image on a second screen that they had just seen, they were rewarded with a drop of juice.  The monkeys were typically 70-75 percent accurate at the memory test.

During the test a variety of inputs to the L2/3 and outputs to the L5 brain regions were recorded.  Lead author, Wake Forest University Professor Robert Hampson describes, "Inputs to that pattern may be blood flow, temperature, the electrical activity of other neurons, and even the prior electrical activity of the same cell."

The next step was impairment.

To simulate a brain injury or cognitive degeration, the monkeys' L2/L3 region -- which acted as the inputs to the L5 output region -- were doped with cocaine, a dopamine modifier.  Cocaine impaired the learning.

II. Cybernetic Improvement

The final phase was replacement with artificial brain signals.

When the electrodes detect L2/3 inputs, they applied them to a "multi-input multi-output nonlinear" (MIMO nonlinear) model -- which translated them to a desired output.  The tuned algorithm stimulated the L5 region of the brain, producing recollection.

The results were remarkable -- the monkeys not only regained their cocaine-suppressed ability to remember -- it actually was improved.  Comments senior author, Wake Forest Professor Sam Deadwyler, "The reason the MIMO model was effective in improving performance in the task was because we specifically 'tuned' the model to analyze the firing of neurons that occurred when the animals correctly performed the behavioral task; the brain doesn't always produce the full 'correct' pattern on every trial."

Monkey Brain
The memory improvement involved the use of a dual-mode implant capable of learning I/O and restoring it (with improvements). [Image Source: IOP Science]

The impressive results encourage Professor Deadwyler that the system may soon be applicable to humans with brain injuries.  He comments, "In the case of brain injury or disease where larger areas are affected, the system would record the inputs to that area from other areas and, when they occur, program the delivery of the appropriate output patterns to brain regions that normally receive signals from the injured area, thereby restoring lost brain function."

But the fact that the study improved neural function over the normal baseline raises an even more intriguing possibility -- someday people may be able to use neural implants to improve their memory and response, as desired.  Of course such an application would likely produce an intense ethics debate.

The research was published [full-text PDF] in the peer-reviewed journal Journal of Neural Engineering.  All of the animal experiments in the study were reviewed and approved by the Institutional Animal Care and Use Committee of Wake Forest University, in accordance with U.S. Department of Agriculture, International Association for the Assessment and Accreditation of Laboratory Animal Care (IAAALAC), and National Institutes of Health guidelines.

Source: Alpha Galileo Foundation

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