Saturday, August 23, 2014

Thought Implants – Is This The Future Of The Mind?

With incredible technology at our fingertips, scientists are now more than ever before striving to understand the mind, looking to answers questions such as: “How quickly can the brain think?” and “How does the mind work?” Are we getting any closer to having these questions answered?

The basic structure and function of neurons – brain cells that process and transmit information through electrical and chemical signals – were discovered by Santiago Ramón y Cajal in Spain in the late 19th century. From that point forth, humanity has made amazing strides in creating and using technologies to record brain activity and understand its patterns – from magnetic resonance scanners to recording neural communication using electrodes on the scalp and the brain.

The mystery of what brain patterns really mean – often referred to as the “neural code” – continues to bewilder neuroscientists, although they have made considerable progress, particularly over the last couple of decades. We now understand which parts of the brain are responsible for some specific tasks, for example the hippocampus is known to be important for spatial navigation. Now, some researchers are realizing the challenge in decoding the “neural code”, so they are writing their own by studying which patterns correspond to which actions. Albert Lee and Matthew Wilson, of the Massachusetts Institute of Technology (MIT) established this approach in 2002, analyzing patterns in the brain of a rat as it runs through a maze:

“While the rat runs the maze we record where it is, and simultaneously how the cells in the hippocampus are firing. The cell firing patterns are thrown into a mathematical algorithm which finds the pattern that best matches each bit of the maze. The language of the cells is no less complex, but now we have a Rosetta Stone against which we can decode it. We then test the algorithm by feeding it freshly recorded patterns, to see if it correctly predicts where the rat was at the point that pattern was recorded.” (source)

This technique comprised of highly-specialized measurement systems and exceedingly complicated algorithms, won’t give us all the answers today because many rules exist in the brain. In the specific example above, Lee and Wilson were only studying patterns from the hippocampus and can’t distinguish patterns that aren’t about maze running. Yet, they discovered that a specific sequence of neural activity was repeated in the rat’s brain while it slept after running the maze, when compared to the absence of this sequence when the rat slept prior to the experiment. The sequence during sleep was about 20 times faster than the same sequence during the actual activity.

These types of experiments are helping us gain insight into the idea of sleep learning: the ability of the unconscious mind to absorb new information and consolidate information you’ve gathered throughout your day. Studying accelerated replay of thought patterns may also help us gain insight into the capabilities of the subconscious brain that is not restrained by the five senses and the constant bombardment on these senses that is modern society.

“I don’t think there’s any doubt we’ll eventually understand the brain. The big question is how long it’s going to take.” ~ Gary Marcus, New York University, editor of The Future of the Brain: Essays by the World’s Leading Neuroscientists (source)

These types of new techniques may provide the keys to stopping cognitive decline, helping patients who are mentally aware but unable to move or speak, and even decode the brain activity of patients in a vegetative state. Here is an example:

“First, the doctors ask the patients to imagine activities which are known to active specific brain regions – such as the hippocampus. The data is then decoded so that you know which brain activity corresponds to certain ideas. During future brain scans, the patients can then re-imagine the same activities to answer basic questions. For instance, they might be told to imagine playing tennis to answer yes and walking around their house to answer no – the first form of communication since their injury.” (source)

Further research and innovation is also taking place in practical domains such as brain-computer interfaces, including transcranial direct current stimulation (TDCS) where the brain is stimulated with electricity, as well as implant technologies. According to Michael Weisend, a neuroscientist at Wright State Research Institute, TDCS shows promise as a means of treating depression, epilepsy, and other drug-resistant brain disorders, although many questions remain about long-term effectiveness of this technique. “TDCS is more of a shotgun approach than a scalpel approach,” Weisend says. A small dose of electricity will affect a broad range of brain cells, in addition to the region targeted.

Neural implants show potentially far more promise, if you are willing to put a computer chip or sensor inside your skull. Implants are already being used to transmit sound and provide a type of “hearing” for certain deaf persons, while others capture images and transmit them to the brain, providing “vision” for certain blind patients. Paralyzed or quadriplegic patients will see more opportunities for an interface with robotic limbs, where a sensor in the brain reads neural activity and puts it into action. Other future applications include neural enhancements developed for improving memory, but in this scenario, researchers are still trying to understand how the brain codes and stores memories. Seems like a huge hurdle, yet scientists believe we’ll solve many of the brain’s mysteries within the next 50 years.

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