How we reviewed Neuralink

At the end of August, Elon Musk held the second presentation of the Neuralink technology – a neurointerface for reading brain activity. The first version of the device was presented by Max in July 2019. Then the editors of J Med Internet Res magazine turned to scientists from the Laboratory of Neuroscience and Cognitive Technologies of Innopolis University for a review. Alexander Pisarchik, Vladimir Maksimenko and Alexander Khramov gave expert comments on a new method of implanting electrodes into the brain. In this article, university staff take apart Musk’s new technology.

Own comment on technology Neuralink we published in October 2019. Compared to last year’s presentation, the appearance of the device has changed – now it is a miniature round tablet the size of a coin and a tongue made of a bundle of electrodes, which, by the way, have become smaller. Initially, 3072 electrodes were announced, now there are 1024 left.

It can be assumed that the change in the number of electrodes is associated with the tasks of the device. The device aims to recognize specific brain activity. The presentation showed how it is used to read physical activity. For this task, a chip must be implanted into the motor cortex. This is a small area and 1000 electrodes are likely sufficient.

If we want to solve another problem – to stimulate the visual or auditory centers, then it is necessary to implant the chip in other areas of the brain. Moreover, to control complex cognitive activity, the electrodes must cover multiple areas at the same time. This is not a question of the number of electrodes, but of the safety of such an operation.

There are also new features. When asked by journalists whether it would be possible to control Tesla using Neuralink, Max answered positively, adding that all senses: sight, hearing, touch are electrical signals that are sent by neurons to the brain. Given the above, it can be assumed that the technology is applicable to control smart home and the Internet of things. The presentation also said that the chip can broadcast music and work with various devices via a Bluetooth connection, and a mobile application will be developed to control Neuralink. Musk likened the new prototype to Fitbit’s fitness bracelets with only small wires in the skull.

Let’s take a look at why the technology is new and why Neuralink could be a breakthrough in the treatment of cognitive impairment. To do this, we abstract from marketing taglines about chip-based control in StarCraft and conversations about chipping people.

Device prototype a year ago and now

Why the Mask project is promising

The idea behind Neuralink is based on a computer brain interface. The term “brain-computer interface” (BCI) appeared in the early 1970s, and the first attempts to study neural activity in monkeys were carried out as early as the 1960s. Today, work in this direction is promising for rehabilitation in case of motor dysfunction.

Neuralink enables the next generation of invasive techniques. The device contains up to 1024 electrodes, distributed over dozens of threads, with the help of which it is connected to the brain. To overcome the surgical limitation, the developers have created a neurosurgical robot that injects up to six threads per minute with micrometer precision.

The technology can serve as a prototype for an invasive neurointerface for clinical applications. Multi-electrode neurointerfaces can become the basis for new technologies and medical solutions for paralyzed people. The development of technology will make it possible to interact with the external environment without restrictions through integration into a smart home and the Internet of Things.

Neuralink has no analogues in terms of the number of registered channels. Existing BCIs, which use invasive recordings from several dozen neurons, already allow monkeys and humans to control the movements of the manipulator with the power of thought. The journal Nature published works that demonstrate how a monkey is eating robotic arm and how completely paralyzed patients grasp and move objects with manipulator

Device strands interact with the brain

BCIs are promising for detecting hidden information about the work of the brain, which cannot be obtained using conventional communication channels. The use of non-invasive BCIs is limited by the small number of recognizable commands. This limitation arises from the noise and non-stationarity of non-invasive EEG or NIR spectroscopy recordings.

In this regard, invasive electrodes are more resistant to interference and artifacts, and allow obtaining high-quality records of neural activity. However, invasive recording requires more electrodes to cover the distributed areas of the brain. With the help of Neuralink methods, this problem can be solved.

How to Invasively Predict Epilepsy Seizures

For us, the Mask’s technology is interesting, including from the point of view of our own developments. At the Laboratory of Neuroscience and Cognitive Technologies, we are working on a project to prevent epileptic seizures.

We have developed a BCI that, using three electrodes implanted in the rat’s brain, can predict epileptic seizures with an accuracy of 90%. However, there are problems associated with the large number of false predictions. When it comes to a seizure prevention system using electrical stimulation, false predictions lead to a lot of unnecessary stimulation. Our interface was able to minimize the number of false predictions, but the seizure prediction accuracy dropped to 50%.

Read more about the developments of Innopolis University in the field of prevention of epilepsy attacks

Neuralink expands the ability to read brain activity signals. Most likely, using 1000 channels instead of three will significantly improve the accuracy of predictions of an epileptic seizure and reduce the number of false predictions.

To predict epileptic seizures, neural activity must be recorded in predetermined focal areas of the brain, where activity is manifested first of all, and pathology is most pronounced. In this case, you can quickly detect an approaching attack.

The next-generation BCIs that Neuralink could bring about involves stimulating the brain to interrupt or even prevent epileptic seizures in drug-resistant people.

The irreplaceable robot surgeon

Back in the first presentation last summer, Musk showed a prototype of a neurosurgical robot for implant placement. This is a very important advantage, because BCIs are not used in clinical practice, including due to surgical difficulties and biocompatibility problems. The robotic surgeon is very fast – sets up to six electrodes per minute. The Neuralink team aims to reduce the implantation time to an hour and perform the operation under local anesthesia to send the patient home the same day.

According to the idea of ​​the developers, the problem of biocompatibility will be solved by the use of biocompatible polyimide with a thin film of gold. Impedance and biocompatibility must be considered when selecting materials. The Neuralink team tested a polymer doped with polyethylene dioxythiophene with polystyrene sulfonate and iridium oxide. As a result, we achieved a lower impedance for the former, but better biocompatibility for the latter. The developers promise to continue research in this direction and test hypotheses on other types of conductive electrode materials and coatings.

Neuralink Robot Surgeon

Our questions to Neuralink

It would be interesting to know if it is possible to deliver electrical impulses to cells and simultaneously record neural activity. In other words, does stimulation retain the ability to simultaneously record neural activity with minimal artifacts.

If this functionality is implemented, it will solve another important problem in the field of BCI – the ability to continuously adjust neural activity. For example, by preventing an epileptic seizure by electrical stimulation, it will be possible to control the effectiveness of this process. It will be possible to select the optimal intensity of stimulation to prevent an attack while minimizing the negative effect on the brain.

Looking far ahead, among the undesirable effects of BCIs with electrodes implanted in the human brain, one can note the potential to control and manipulate human behavior not only through the media, but also to send commands directly to the brain. This places increased demands on encryption and protection of data and protocols used in BCI. Now it seems fantastic, but in the future this question will surely arise.

There is much debate about the ethics of such methods. It is interesting how the public position on this matter will be formulated in the end. Would the majority want to voluntarily install neuroimplants? Write in the comments what you think about this, would you agree to such a thing to find Tesla in the parking lot or turn on the light in the apartment by the power of thought?

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