- Brain-Computer Interfaces (BCIs) have emerged as a fascinating field with immense potential to revolutionize human-machine interaction. By directly linking the human brain to external devices, BCIs hold promise for a wide range of applications, from assisting individuals with disabilities to enhancing virtual reality experiences. However, realizing the full potential of BCIs requires addressing significant challenges and harnessing cutting-edge technologies. In this article, we explore the future of BCIs, highlighting the key challenges faced and the exciting technologies paving the way for groundbreaking advancements.
Understanding Brain-Computer Interfaces (BCIs)
Every action our body performs begins with a thought, and with every thought comes an electrical signal. The electrical signals can be received by the brain-computer interface, consisting of an electroencephalograph (EEG) or an implanted electrode, which can then be translated, and then sent to the performing hardware to produce the desired action. BCI is an alternative system built on artificial mechanisms and acts as a bridge between the brain and external devices. The aim of BCI is to convey human intentions to external devices by directly extracting brain signals. Eventually, the brain and computers would be highly integrated.
The brain-computer interface (BCI) allows people to use their thoughts to control not only themselves, but the world around them. BCI enables a bidirectional communication between a brain and an external device, bidirectional generally includes direct neural readout and feedback and direct neural write-in.
Over the last few decades, several neuroengineering and neuroscience studies have demonstrated how Brain Computer Interface (BCI) technology can uncover the neural mechanisms underlying various tasks and translate them into commands that control an application or device
Brain-computer interfaces are being applied in neuroprosthetics, through which paralyzed persons are able to control robotic arms, neurogaming where one can control keyboard, mouse etc using their thoughts and play games, neuroanalysis (psychology), and in defense to control robotic soldiers or fly planes with thoughts.
BCIs may replace lost functions, such as speaking or moving. They may restore the ability to control the body, such as by stimulating nerves or muscles that move the hand. BCIs have also been used to improve functions, such as training users to improve the remaining function of damaged pathways required to grasp. BCIs can also enhance function, like warning a sleepy driver to wake up. Finally, a BCI might supplement the body’s natural outputs, such as through a third hand.
While many studies have demonstrated the theoretic potential of BCI, especially by deploying novel machine learning methods for detecting distinct task-specific attributes of the brain, a point of concern that remains is that the studies are still confined to lab settings and mostly limited to healthy able-bodied subjects. A few case-studies using invasive and non-invasive BCIs have demonstrated the application of BCI as a motor assistive technology for survivors of spinal cord injury (SCI).
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Brain-Computer Interface technology
BCIs aim to establish a direct communication pathway between the brain and external devices, allowing individuals to control devices or communicate solely through their thoughts. To measure brain activity, different tools and technologies are utilized, each with varying levels of accuracy and invasiveness.
There are three fundamental techniques to interface with the brain; non-inasive such as electro-encephalography (EEG), invasive through direct connections and electro-corticography (ECoG), also known as intracranial EEG – a sort of half-way house involving electrodes placed on the brain’s exposed surface, rather than hardwired into the brain itself.
Invasive BCIs involve the use of electrodes placed directly within or on the surface of the brain. This technique provides high resolution and precise neural recordings. However, it requires neurosurgery, making it more invasive and necessitating regulatory approvals, which can pose challenges in funding and conducting clinical trials.
Non-invasive BCIs, on the other hand, measure brain activity through external means, typically by placing electrodes on the scalp using electroencephalography (EEG). Some BCIs have been based on metabolic activity that is measured noninvasively, such as through functional magnetic resonance imaging (fMRI). Non-invasive techniques offer convenience and reduced risk of infection compared to invasive methods. They have gained popularity in recent years due to their ease of use and wider accessibility.
In terms of implantable devices used in invasive BCIs, there are limitations to their performance. The mechanical, chemical, and physical properties of these devices often do not match well with the surrounding tissues. This mismatch can lead to tissue damage, decreased information density, and local inflammation and scarring due to the body’s response to foreign materials.
Non-invasive BCIs, particularly EEG-based systems, have seen significant progress in recent years. Advances in recording technology and signal processing techniques have allowed for the identification of new brain signal patterns and more complex control strategies. These developments have been tested in clinical and non-clinical settings, showcasing the potential of non-invasive BCIs in various applications.
Non-invasive BCI has found multiple uses in the areas of medicine such as motor restoration, wheelchair assistance, and treatment of neurological disorders. However noninvasive BCIs suffer from poor efficiency and accuracy, are slow and somewhat uncertain at present, they also tend to make high cognitive demands on the user.
In summary, BCIs utilize different techniques to measure brain activity, ranging from invasive approaches that provide high resolution but require surgery and regulatory approvals, to non-invasive methods that offer convenience and accessibility. Advances in both invasive and non-invasive BCIs continue to push the boundaries of this technology, opening up new possibilities for human-machine interaction and assisting individuals with disabilities.
Advances in BCI technology
In recent years, there has been significant progress in non-invasive BCI research and development, particularly in the field of electroencephalography (EEG)-based BCIs. Researchers and innovators have focused on identifying new brain signal patterns that can be used to infer user intent and enable more complex control strategies.
One of the most promising new BCI technologies is the use of optogenetics. Optogenetics is a technique that uses light to control the activity of neurons. This technique has the potential to greatly improve the accuracy and reliability of BCIs.
Another promising new BCI technology is the use of neural dust. Neural dust is a tiny, implantable device that can record brain activity. Neural dust is much smaller and less invasive than traditional BCI implants, which makes it a more attractive option for many people.
Advancements in recording technology and signal processing techniques have played a pivotal role in driving the progress of non-invasive BCIs. These developments have allowed for more accurate and reliable extraction of meaningful information from brain signals, facilitating improved control of external devices.
Advancements in Neural Signal Acquisition:
To enhance the usability and accuracy of BCIs, significant progress is being made in the field of neural signal acquisition. New electrode technologies, such as flexible and implantable electrodes, offer improved signal quality and longevity, enabling long-term, reliable brain signal recordings. Additionally, wireless and non-invasive techniques, such as electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS), are being developed, allowing for more comfortable and portable BCI systems.
Invasive BCI have greater application in neuroprosthetics compared to non-invasive BCI since in order to understand/regulate the neural connectivity of specific brain areas, it becomes necessary to introduce neural implants (electrodes). One of the critical technologies is material used to make electrodes used to make Brain Computer Interfaces.
Neural Implants and Brain-Machine Interfaces:
Implantable neural devices are on the forefront of BCI research. These devices, placed directly in the brain, offer high-resolution neural recordings and precise control of external devices. Advancements in neural implants include the development of biocompatible materials, miniaturized electronics, and wireless communication, all contributing to long-term functionality and reduced invasiveness. Neural implants hold great promise for restoring sensory perception, treating neurological disorders, and enabling novel cognitive enhancements.
DARPA Brain Modem
Instead of invasive brain surgery, DARPA has developed small brain modem that enters the bloodstream via a catheter and then transmits data. The US military recently successfully implanted and tested its first ‘brain modem’ on an animal subject. Neurologists injected tiny sensors into livestocks’ veins and then recorded the electrical impulses that control the animals’ movements for six months.
The tiny, implanted chip, developed by the Defense Advanced Research Projects Agency (Darpa), uses a tiny sensor that travels through blood vessels, lodges in the brain and records neural activity. The sensor, called a ‘stentrode’, a combination of the words ‘stent’ and ‘electrode’, is the first step in the military’s desire to allow soldiers to control machinery with their minds. The stentrode is the size of a paperclip, flexible and injectable.
“The original goal of the neural dust project was to imagine the next generation of brain-machine interfaces, and to make it a viable clinical technology,” said neuroscience graduate student Ryan Neely. “If a paraplegic wants to control a computer or a robotic arm, you would just implant this electrode in the brain and it would last essentially a lifetime.”
BCI in form of Artificial Skin
John Rogers at the University of Illinois at Urbana-Champaign and his team have built a Brain Computer Interface, in the form of flexible electronic skin that conforms to the body. The interface comprising just of small patch of gold electrodes sticks to the skin through van der Waals forces like a digital tattoo. The patch applied behind the ear, falls off when the build-up of dead skin beneath it loosens its grip.
Their solution does away with the cumbersome electrodes, annoying gels and wires of conventional EEGs described by Rogers as a “rat’s nest of wires attached to devices that interface to the skin with tape and gels and bulky metallic objects”. The team is now working on wireless transmission of data and power, allowing it to work even if the wearer is moving.
Lund University’s Breakthrough for electrode implants
Researchers at Lund University have made a breakthrough in the development of electrode implants for recording neuronal signals from the brain. The success of these electrode implants depends on two crucial factors: bio-friendliness and flexibility.
The brain is surrounded by cerebrospinal fluid (CSF) and housed within the skull. The CSF acts as a protective cushion, allowing the brain to float and move slightly within the skull. This movement occurs during various activities, including breathing, head movements, and even normal physiological processes.
The fact that the brain moves within the skull poses a challenge when designing electrode implants for recording neuronal signals. The electrodes need to be flexible and able to adapt to the brain’s movements without causing damage or disrupting the surrounding tissue. This flexibility is crucial to ensure stable and accurate recordings over an extended period.
The Lund researchers, Professor Jens Schouenborg and Dr Lina Pettersson, have created unique electrodes called 3-D electrodes that are remarkably soft and flexible in all three dimensions. This flexibility allows for stable recordings from neurons over an extended period.
To implant these electrodes, the researchers have devised a technique that involves encapsulating the electrodes in a dissolvable gelatin material, which is gentle on the brain. The electrodes, made of gold leads and insulated with parylene, are designed to follow the brain’s movements, ensuring that they maintain their shape within the brain. The technology, both the electrodes and implantation technique, has been patented by the researchers in Europe and the US.
Previously developed flexible electrodes were unable to maintain their shape after implantation, leading to limited flexibility and irritation of brain tissue. In contrast, the Lund University’s technology allows for the implantation of highly flexible electrodes while preserving their shape within the brain. This breakthrough opens up new possibilities for understanding brain activity and developing more effective treatments for conditions like Parkinson’s disease and chronic pain.
The researchers believe that this technology will provide a deeper understanding of the functioning of the brain and enable the development of improved treatments for various neurological disorders. By eliminating the damage caused by rigid or poorly shaped electrodes, this breakthrough has the potential to revolutionize our ability to study and interact with the brain.
Electronic dura mater for long-term multimodal neural interfaces
A team of researchers at a Swiss technology institute has developed a groundbreaking technology called the electronic dura mater (e-dura). The e-dura is an ultra-flexible electrode implant that mimics the properties of the dura mater, the protective membrane surrounding the brain and spinal cord. This innovative implant can both stimulate and record neuronal activity.
Conventional electrode implants are rigid and have a high elastic modulus, which creates a mechanical mismatch with the soft neural tissues. This mismatch can lead to long-term performance issues with neuroprostheses. To address this problem, the researchers designed and fabricated soft neural implants that closely resemble the shape and elasticity of the dura mater.
The e-dura implant consists of a transparent silicone substrate, stretchable gold interconnects, soft electrodes coated with a platinum-silicone composite, and a compliant fluidic microchannel known as a chemotrode. The interconnects and electrodes enable the transmission of electrical signals for stimulation and recording, while the microfluidic channel allows for localized drug delivery.
In a study involving healthy rats, the researchers compared the long-term biointegration of the soft e-dura implants with rigid plastic implants over a six-week period. The rats with the rigid implants experienced walking difficulties within a few weeks, along with inflammation and deformation of their spinal cords. In contrast, the rats with the e-dura implants did not display motor problems or physiological degradation. Additionally, the e-dura electrodes demonstrated accurate recording and stimulation capabilities in both the brain and spinal cord.
This development represents a significant advancement in neural interface technology. The e-dura implant’s flexibility and biocompatibility make it more compatible with the body’s neural tissues, allowing for improved long-term performance and reduced adverse effects. The e-dura holds great promise for the development of advanced neuroprosthetic devices and treatments for various neurological conditions.
University of Melbourne scientists develop BCI which gets implanted in the brain without surgery
Scientists from the University of Melbourne, in collaboration with the Royal Melbourne Hospital and the Florey Institute of Neuroscience and Mental Health, have developed a breakthrough Brain-Computer Interface (BCI) called a stentrode. This matchstick-sized device is flexible enough to be implanted into the brain’s motor cortex through blood vessels, eliminating the need for invasive brain surgery.
The stentrode captures and decodes brain signals, enabling users to control an exoskeleton attached to their limbs simply by thinking about it. This wireless transmission of commands through the skin opens up possibilities for individuals with paralysis to regain mobility and independence.
The applications of the stentrode extend beyond mobility assistance. It has the potential to benefit people with conditions such as Parkinson’s disease, motor neurone disease, obsessive-compulsive disorder, depression, and even help predict and manage seizures in epilepsy patients.
In late 2017, a select group of paralyzed patients from the Royal Melbourne and Austin Hospitals in Australia will be chosen to participate in a trial, where they will be implanted with the stentrode. If the trial is successful, this groundbreaking technology could be commercially available within six years.
This development represents a significant advancement in the field of BCIs, offering a minimally invasive approach to implanting devices directly into the brain. The stentrode has the potential to revolutionize the lives of individuals with paralysis and various neurological conditions, paving the way for future advancements in neuroprosthetics and enhancing the quality of life for many.
Researchers demonstrate first human use of high-bandwidth wireless brain-computer interface in March 2021
In March 2021, researchers achieved a significant milestone in brain-computer interface (BCI) technology by demonstrating the first human use of a high-bandwidth wireless BCI system. This breakthrough, part of the BrainGate clinical trial, enables individuals with tetraplegia to use an intracortical wireless BCI with an external wireless transmitter, eliminating the need for physical cables that connect the brain sensors to decoding systems.
The wireless system utilizes a small transmitter placed on top of the user’s head, connecting to an electrode array within the brain’s motor cortex through the same port used by wired systems. In a study published in IEEE Transactions on Biomedical Engineering, two participants with paralysis successfully used the BrainGate system with the wireless transmitter to control a standard tablet computer. The study revealed that the wireless system transmitted brain signals with comparable fidelity to wired systems, resulting in similar accuracy for pointing, clicking, and typing tasks.
The researchers emphasize that the wireless BCI system achieves functionality equivalent to wired systems, enabling the use of existing decoding algorithms. The elimination of physical tethers opens up new possibilities for BCI applications. This development represents an early but crucial step toward the ultimate goal of a fully implantable intracortical BCI system that restores independence for individuals who have lost motor function.
Previously, wireless BCI devices with lower bandwidth had been reported, but this is the first system capable of transmitting the full spectrum of signals recorded by an intracortical sensor at high broadband fidelity. The high-broadband wireless signal opens doors for advanced clinical research and human neuroscience studies that are challenging to conduct with wired BCIs.
Overall, this achievement paves the way for further advancements in wireless BCI technology and brings us closer to developing fully implantable systems that can significantly improve the quality of life for individuals with motor impairments.
Enhancing Communication and Restoration of Function:
BCIs have the potential to restore communication and motor function for individuals with disabilities. Future developments aim to expand the capabilities of BCIs, enabling more natural and expressive communication, as well as finer control of prosthetic limbs. Researchers are exploring ways to decode complex movements and intentions from brain signals, allowing for more intuitive and seamless interactions between the brain and external devices.
In recent years, advances in machine learning (ML) have enabled the development of more advanced BCI spellers, devices that allow people to communicate with computers using their thoughts. In the next few years, we might be able to control our PowerPoint presentation or Excel files using only our brains. Some prototypes can translate brain activity into text or instructions for a computer, and in theory, as the technology improves, we’ll see people using BCIs to write memos or reports at work.
Signal Processing and Machine Learning:
Effectively processing and interpreting neural signals is a critical challenge in BCI technology. Machine learning algorithms are playing a crucial role in decoding brain activity patterns and translating them into meaningful commands. Advances in deep learning and artificial intelligence have shown promising results in improving the accuracy and speed of signal processing, enabling more efficient and precise control of external devices through BCIs.
A major proportion of BCI literature has focused on improving performance of BCI applications by enhancing the decoding performance of signal processing and machine learning algorithms. While this is an important contributing factor, research has also demonstrated that mutual learning of the machine and the user is critical for a successful closed-loop implementation of BCI.
In any case, the fundamental deciding factor for the efficiency of a BCI system is how well the end-user can generate distinct and consistent brain activity corresponding to each mental task. This in turn results in well-calibrated BCI decoders that can offer better real-time performance. However, the calibration paradigms for data collection, often involve time-consuming, monotonous and non-engaging visual interfaces.
Semantic decoder brain-computer interface (BCI) system developed by researchers at the University of Texas at Austin.
The study, which was published in the journal Nature Neuroscience in May 2023, involved 10 participants who were unable to speak due to amyotrophic lateral sclerosis (ALS). The participants were trained to imagine reading a story while their brain activity was recorded using functional magnetic resonance imaging (fMRI). The fMRI data was then used to train a semantic decoder AI model.
The semantic decoder was able to successfully translate the participants’ brain activity into a continuous stream of text. The accuracy of the system was 94%, which is significantly higher than previous BCI systems that have been developed.
The research, published in the journal Nature Neuroscience, was carried out by Jerry Tang, a doctoral student in computer science, and Alex Huth, an assistant professor of neuroscience and computer science at UT Austin. Their innovative work relies in part on a transformer model, a technology similar to the one employed by OpenAI’s ChatGPT and Google’s Bard.
The semantic decoder system has the potential to revolutionize communication for individuals who are conscious but physically unable to speak. The system could be used to help people with ALS, stroke, and other conditions that affect speech. The system could also be used to help people who are in a coma or vegetative state.
The semantic decoder system is still in its early stages of development, but it has the potential to make a significant impact on the lives of people who are unable to speak. The system could help people to communicate with their loved ones, to express their thoughts and feelings, and to regain a sense of independence.
The semantic decoder system is based on a transformer model, which is a type of AI model that is known for its ability to process long sequences of data. Transformer models are made up of a stack of self-attention layers, which allows them to learn long-range dependencies in the data.
The semantic decoder system was trained on a dataset of fMRI data from participants who were imagining reading stories. The fMRI data was used to train the transformer model to associate different patterns of brain activity with different words and phrases.
The semantic decoder system has the potential to be used to help people with ALS, stroke, and other conditions that affect speech. The system could be used to help people who are unable to speak to communicate with their loved ones, to express their thoughts and feelings, and to regain a sense of independence.
The semantic decoder system is still in its early stages of development, but it has the potential to make a significant impact on the lives of people who are unable to speak. The system is currently being tested with a larger group of participants, and the researchers are working to improve the accuracy and reliability of the system.
However, the system is not yet practical for use outside of a laboratory setting due to its reliance on time-consuming fMRI machines. The researchers believe that their work could be adapted to more portable brain-imaging systems, such as functional near-infrared spectroscopy (fNIRS).
The researchers addressed concerns about the potential misuse of their groundbreaking semantic decoder technology. The artificial intelligence system, which translates brain activity into a continuous stream of text, has raised questions about the possibility of unauthorized access to individuals’ thoughts.
However, the researchers stressed that decoding was only effective with cooperative participants who willingly participated in training the decoder. When tested on untrained individuals or those who actively resisted by thinking other thoughts, the results were unintelligible and unusable.
Breakthrough AI Tech Enables Brain Stroke Survivor To Communicate Through Avatar
Researchers at the University of California, San Francisco (UCSF) and the University of California, Berkeley (UC Berkeley) have developed a new technology that allows people who have suffered a stroke to communicate through an avatar. The technology uses a combination of brain-computer interface (BCI) and artificial intelligence (AI) to translate brain signals into speech.
The technology has been tested on a woman named Ann, who suffered a stroke at the age of 30 that left her paralyzed and unable to speak. Ann was implanted with a BCI device that consists of a thin array of electrodes placed on the surface of her speech cortical regions of her brain. The BCI device records Ann’s brain signals as she attempts to speak.
The researchers then used AI to train a computer model to translate Ann’s brain signals into speech. The computer model was trained on a large dataset of speech and brain signals from healthy individuals.
Once the computer model was trained, the researchers developed a digital avatar that could be controlled by Ann’s brain signals. When Ann thinks about speaking a word, the computer model translates her brain signals into speech and the avatar speaks the word.
The technology is still under development, but it has the potential to revolutionize the way that people who have suffered a stroke communicate. It could also be used to help people with other communication disorders, such as cerebral palsy and amyotrophic lateral sclerosis (ALS).
The researchers believe that the technology could be available for clinical use within the next five years.
New use cases
As BCI technology continues to develop, we can expect to see a number of new and exciting applications for these devices. BCIs have the potential to help people with disabilities regain lost function, and they could also be used to improve our cognitive abilities.
But new use cases are being identified all the time. For example, BCIs can now be used as a neurofeedback training tool to improve cognitive performance. For example, your BCI could detect that your attention level is too low compared with the importance of a given meeting or task and trigger an alert. BCIs can detect the mental state of a worker and adjust nearby devices accordingly (smart home utilization). for example, It could adapt the lighting of your office based on how stressed you are, or prevent you from using your company car if drowsiness is detected.
A Toronto-based startup called “Muse” has developed a sensing headband that gives real-time information about what’s going on in your brain. The startup already has a “Corporate Wellness Program” to “help your employees lower stress, increase resilience, and improve their engagement.” Other headbands on the market also use proprietary sensors to detect brain signals and leverage machine learning algorithms to provide insights into the engagement levels of users/workers. They can track whether someone is focused or distracted.
Researchers are also experimenting with “passthoughts” as an alternative to passwords. Soon, we might log into our various devices and platforms using our thoughts. As described in this IEEE Spectrum article, “When we perform mental tasks like picturing a shape or singing a song in our heads, our brains generate unique neuronal electrical signals. A billion people could mentally hum the same song and no two brain-wave patterns generated by that task would be alike. An electroencephalograph (EEG) would read those brain waves using noninvasive electrodes that record the signals. The unique patterns can be used like a password or biometric identification.”
U C Berkeley engineers have built the first dust-sized, wireless sensors that can be implanted in the body without surgery, bringing closer the day when a Fitbit-like device could monitor internal nerves, muscles or organs in real time.Because these batteryless sensors could also be used to stimulate nerves and muscles, the technology also opens the door to “electroceuticals” to treat disorders such as epilepsy or to stimulate the immune system or tamp down inflammation.
Here are some of the potential applications of BCIs:
- Restoring lost function. BCIs could be used to help people with disabilities regain lost function. For example, BCIs could be used to help people who are paralyzed control prosthetic limbs.
- Improving cognitive abilities. BCIs could be used to improve our cognitive abilities. For example, BCIs could be used to help us learn new things faster or to improve our memory.
- Augmenting our senses. BCIs could be used to augment our senses. For example, BCIs could be used to give us night vision or to allow us to see in the infrared spectrum.
- Creating new forms of communication. BCIs could be used to create new forms of communication. For example, BCIs could be used to allow people to communicate telepathically.
Ethical Considerations and User Acceptance:
As BCIs progress, ethical considerations surrounding privacy, data security, and informed consent become increasingly important. Balancing the potential benefits with concerns about personal autonomy and data ownership is crucial. Engaging users in the development process and ensuring transparency are essential for gaining public trust and widespread acceptance of BCIs.
The future of Brain-Computer Interfaces is filled with exciting possibilities. Overcoming challenges in neural signal acquisition, signal processing, and user acceptance will unlock the full potential of BCIs. With advancements in neural implants, machine learning algorithms, and ethical considerations, BCIs have the potential to significantly improve the lives of individuals with disabilities and open up new avenues for human-machine interaction. The future holds great promise for BCIs, and as technology continues to advance, we can expect remarkable breakthroughs that will shape our understanding of the human brain and transform the way we interact with the world around us.