Fiction on the threshold
Brain implants today and in the future
Ivan Sychev, Geektimes
Brain implants are classics of science fiction, they are found in films ("Johnny Mnemonic") and books ("Enclaves"). Often in the fantasies of writers and screenwriters, they are designed to replace and expand memory, increase the ability to learn and gain access to the network. In the "Enclaves", an additional processor could be inserted into the port in the cranium, repeatedly increasing the brain's abilities.
There are already examples of brain implants in real life. One of the first devices working inside the skull in order to obtain information was a cochlear implant to compensate for hearing loss with sensorineural hearing loss: in this disorder, hearing is lost due to damage to the sound-receiving apparatus. Neuroprosthesis converts electrical impulses from an external microphone into signals understandable to the human nervous system. The technology has been used since the 1960s.
Prosthetics of the eye works according to a similar system: data from the camera built into the glasses is transmitted to the main device, which converts the image into a signal coming to the electrodes attached to the retina of the eye or implanted in the brain. While all devices from this area allow you to see only the outlines of objects, there is no question of colors.
One of the means of helping patients with epilepsy is invasive monitoring. Electrodes are implanted in the brain of patients, which help doctors determine the zone of the onset of an epileptic seizure and its spread. The precise determination of these parameters allows effective surgical measures to be carried out for the treatment of the patient. Another area that should help people with Alzheimer's disease or depression, in which drugs affect the brain, is implants for direct injection of drugs into the brain, which a team from the Massachusetts Institute of Technology is working on.
There are experiments in the field of rarer diseases. One of the first cyborgs, Neil Harbisson, has not seen flowers since childhood due to achromatopsia. He developed a device that allows him to "hear" color.
Another promising direction is improving memory. Scientists still don't fully understand how the human brain works, but they are already able to restore some of its functions – devices literally imitate its behavior, recreating the received electrical signals by stimulating the right areas in the correct sequence.
Theodore Berger from the University of Southern California has been looking for more than 25 years for a way to improve human memory using devices implanted in the brain. In the early 2000s, a group of scientists under his leadership created one of the first hippocampal prostheses for experimental rodents. This area of the brain is responsible for the transition of short-term memory into long-term memory. Symptoms of the most common form of dementia – Alzheimer's disease – include a disorder of short-term memory, and one of the early signs of the disease is a decrease in the volume of this part of the brain.
In 2010, Berger conducted a series of experiments on rats with implanted electrodes that captured the CA3 and CA1 regions of the hippocampus. Rodents solved problems while in a cell with two levers hiding in the wall. First you had to press the lever, then it was removed into the wall for a certain time, and then the rat chose one of the two levers that appeared. To get water, the rodent had to press the lever opposite to the starting lever, and if he pressed the same one, the test subject was punished by turning off the light. The time to solve the problem was gradually increased from 5 to 60 seconds. The electrodes at this time recorded the signals of neurons when the lever was pressed.
The recorded "code" allowed us to create a stimulation model to improve the performance of solving this problem. On the graph in the lower left part of the image, the orange color indicates the results obtained during brain stimulation using this model, and the blue color indicates the control results recorded at the previous stage of the experiment. At the same time, the stimulation was carried out not at the moment of guessing the lever, but at the moment of the first interaction with it – that is, for memorization.
In 2011, Berger's team demonstrated the ability to turn on and off the animal's memory using sensors in the rat brain. Rodents with the help of drugs blocked the ability to create long–term memories - blocked the work of the CA3 region, and then with the help of electrodes restored it. Artificial signals recreating the activity of neurons improved the percentage of correct responses.
In 2017, experiments began on humans with electrodes implanted in the brain. Twenty volunteers solved memory tasks. First, the implant registered neural signals, and then "helped" the person to remember the answer to the task by stimulating the brain. Then short-term memory was improved by 15%. A new study published on March 28, 2018, raised this figure to 35-37%. Since 2014, the DARPA agency has been interested in the issue of memory recovery: it funded this research, and also provides grants for research work in the field of creating feedback sensors implanted in the brain.
For the new study, a team of scientists from Wake Forest Baptist Medical Center and the University of Southern California recruited eight epilepsy patients participating in a diagnostic brain mapping procedure. Electrodes were placed in different parts of the participants' brains. The study was aimed at episodic memory, which contains information useful for a short period of time – it is with it that the main problems arise in people with Alzheimer's disease, stroke and head injuries.
In one of the tests, patients performed tasks to memorize colored geometric shapes while sensors recorded the activity of neurons in the hippocampus. After viewing a given figure, they had to choose it from four or five options. Brain stimulation in the correct sequence increased the efficiency of solving such tasks by 37%. The second test consisted of guessing the photos an hour after they were shown. This time, the stimulation allowed to improve the indicators by 35%.
"We have proved that we can get into the patient's memory, record the signal and transmit it back. Even in cases where a person's memory is weakened, it is possible to identify patterns of neural signals and separate correct patterns from incorrect signals. Then we can help the patient's brain to form new memories – not to replace the memory function itself, but to strengthen it. Now we are trying to determine how much memory function can be improved, but in the future we hope to help people with recording specific memories – for example, where they live, what their grandchildren look like when their own memory stops working," says Robert Hampson, professor of physiology, pharmacology and neurology at Wake Forest Baptist Medical Center, one from the authors of the study.
The startup KerNEL is working on the commercialization of Berger's technology. The founder of the company, Brian Johnson, wants not just to start selling memory recovery devices, but also to create new implants to improve human attention and creativity, that is, in fact, to go beyond the medical use of devices. In this case, the devices have a chance to get away from having to comply with all the requirements for medical equipment and stand on a par with fitness bracelets.
Johnson has money for the project thanks to the sale of PayPal for $ 800 million in 2013. Another person associated with this project, Elon Musk, registered the company Neuralink in 2016 and hired people related to brain research. In the short term, Musk wants to produce devices for the treatment of various brain diseases, but in the future, just like Johnson, he wants to improve people. Including by giving them telepathic capabilities. In March 2018, it became known that Musk's company had received permission to experiment on animals in San Francisco. Neurlalink continues to look for specialists in the team – vacancies of engineers in the field of robotics, microelectronics, software developers and others are posted on the site. One of the main requirements is the desire to overcome big challenges.
DARPA has been working for the past two years to create implantable neural interfaces to obtain "unprecedented signal resolution and bandwidth for information transfer between the human brain and electronic systems." There are interesting examples of elastic electrodes, such as those developed by scientists from Linkoping University (Sweden) Devices: Based on it, researchers from Lund University in Sweden have developed a solution capable of storing and processing data from more than 1 million neurons in real time and providing feedback at a speed of 25 milliseconds.
Further development of hardware and processing solutions will make it possible to transfer part of brain research into the field of software. To increase efficiency, standardization of all elements of neurocomputer systems is necessary. But for now, this is also science fiction.
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