Neural Prosthetics

Today a faculty candidate gave a talk on his research and I had little intention of sitting and listening until I read the caption "Neural Prosthetics" as he reviewed his slides. Now this would catch most peoples and make many wonder what exactly that means, so I listened.

The essence of the discovery was relatively simple. What the speaker, Dr. Opris, had done is to measure the action potentials produced by a particular group of neurons then measure the effect in a lower layer of the cortical tissue. Now the key was that according to Granger Causality the action of B, given A, is causally related if the probability of B eliciting some action is greater if A acts first. This concept is commonly used to determine neural connectivity in small arrays of neurons. So by "listening" to the neurons he was able to determine how they work together to allow the subject to accomplish a task.

The experiment consisted of a monkey equipped with the electrode implanted in his head, and trained to move a cursor to a target. Once the cursor is moved to the target he is presented with an image. Then the monkey must select the image which was presented previously, and correct selection was positively reinforced.

The portion of the study related to prosthetics devices was brief but had broad implications. Simply put, Dr. Opris, discovered he could interfere with the monkey's ability to successfully perform his task by electrically biasing the neurons involved in performing said task. The success rate dropped significantly in the study. Now this result seems like nothing special, but there are two key points of interest. The first is through modification of the initial state of the neuron he was able to achieve successful modulation of the monkey's cognitive abilities.

Although this simple application seems like just another way of messing with a monkey's head, quite literally. If you consider that one of the major symptoms of autism is hyper-sensitivity to stimulus, a treatment that can modulate stimulation can go a long way to restoring functionality. Further, if neural function can be blocked, what is to say the process can't be reversed and have function restored; hence providing treatment to diseases such as Alzheimer's.