Podcast Summary
Brain-computer interfaces: Brain-computer interfaces (BCIs) have advanced significantly, enabling paralyzed patients to control computer cursors with their thoughts and explore the possibility of controlling prosthetic limbs directly with their brains. Practical challenges and ethical questions remain as researchers continue to explore the potential uses and limitations of BCIs.
Brain-computer interfaces (BCIs) are a type of technology that directly interact with the brain, either sending information in or receiving information out. These interfaces have advanced significantly in recent years, enabling paralyzed patients to control computer cursors with their thoughts and explore the possibility of controlling prosthetic limbs directly with their brains. The technology works by recording brain signals, which the computer then translates into actions. Dr. Nicholas Hatzopoulos, a behavioral neuroscientist and professor at the University of Chicago, explained that BCIs can encompass a wide range of devices, and he has been working on using them to help patients control devices with their body movements encoded in the brain. However, practical challenges and ethical questions remain as researchers continue to explore the potential uses and limitations of BCIs. For example, how can BCIs be made more reliable and efficient? And what are the ethical implications of directly accessing and manipulating the brain? As we delve deeper into the world of BCIs, it's clear that this technology has the potential to revolutionize the way we interact with computers and the world around us. But it also raises important questions about the nature of the mind, the brain, and what it means to be human.
Brain-machine interfaces: BMI involves implanting electrodes in brain areas to decode neuron signals into device control, with two approaches: biomimetic, mimicking natural responses, and non-biomimetic, using arbitrary algorithms requiring learning
Brain-machine interfaces involve implanting electrodes in specific brain areas to pick up electrical signals from neurons, amplify them, and decode them into useful information for controlling devices like cursors, robotic limbs, or robots. This process is similar to a digital computer as neurons fire pulses, which are then decoded into commands. Two approaches exist: biomimetic, which mimics natural biological responses, and non-biomimetic, which uses arbitrary decoding algorithms requiring learning. The biomimetic approach requires no learning, while the non-biomimetic one necessitates patient or animal adaptation.
Neural prosthetics training: Training the brain to control artificial limbs involves creating electrical activity patterns, researching other brain areas, and overcoming engineering challenges for reliable and long-lasting electrodes and accurate signal translation.
The development of neural prosthetics involves training the brain to control artificial limbs through practice, similar to how infants learn to reach and grasp objects. This process involves creating the right patterns of electrical activity in the brain to move the limb. Research is also being conducted on other areas of the brain, such as the parietal cortex, which carries movement information earlier than the motor cortex. However, the biggest challenges in the field are engineering-related, including developing reliable and long-lasting electrodes for recording electrical signals from the brain. These devices need to last at least a decade without needing replacement. Another challenge is ensuring that the signals from the brain are accurately translated into actions by the prosthetic limb. Overall, the field of neural prosthetics is making significant progress, but there are still many technical hurdles to overcome before these technologies can be widely available to patients.
Neural implants and immune responses: Researchers are developing softer materials for electrodes to reduce immune responses, but limitations exist such as inability to undergo MRIs with implant in place. Users often report feeling neural implants as part of their body over time.
The interaction between the brain and neural implants can trigger immune responses, which can weaken the signals and make it harder for the device to function effectively. Researchers are working on developing softer materials for electrodes to reduce these reactions. However, there are limitations to what can be done, such as the inability to undergo MRIs with the implant in place. The phenomenon of phantom limb sensations, where amputees feel their missing limb, does not typically interfere with using a prosthesis controlled by a neural implant. Instead, users often report that the device feels like a part of their body over time. Early users described controlling a cursor on a computer screen as if it were an extension of their own limb.
Brain and tongue movements: The cortex, often considered the higher area of thought, encodes information about the tongue's shape and movement with high precision, challenging the assumption that feeding and swallowing are primarily controlled by lower brain areas.
Our brain learns to control complex movements, like moving a cursor with a mouse or controlling the tongue, without consciously thinking about the intermediate steps. This is similar to how we learn a foreign language, where we initially translate every word into our native language, but over time, we speak and understand it directly. This discovery was made in a recent study that explored mapping the movements of the tongue, a soft and flexible body part with infinite degrees of freedom, which we can control with great precision. The researchers were surprised to find that the cortex, often thought of as the higher area of thought, encodes information about the tongue shape and movement with high precision. This discovery has potential applications for people with speech or swallowing disorders, as it could lead to better understanding and treatment of these conditions. The researchers were initially skeptical that they would find any significant information in the cortex, as they believed that feeding and swallowing were primarily controlled by lower brain areas. However, their findings challenge this assumption and provide new insights into the complex relationship between the brain and the body.
Swallowing aid prosthetic: Researchers are developing a prosthetic device to aid swallowing and feeding for dysphagia patients by stimulating muscles electrically based on cortex signals, highlighting brain's plasticity and ability to learn new skills
Researchers are exploring the development of a prosthetic device to aid in swallowing and feeding for individuals with dysphagia. This device would not replace the tongue but rather stimulate the muscles electrically to create proper swallowing behavior. The trigger for this stimulation would be a signal from the cortex indicating the person's intention to swallow. This research not only has the potential to improve the quality of life for those affected by dysphagia but also provides valuable insights into the brain's plasticity. The discovery that both animals and humans can learn to control the device despite it not being a natural process highlights the brain's ability to adapt and learn new skills. This research not only holds significant practical applications but also sheds light on the intricacies of the brain's functioning.
Brain Plasticity and BMIs: Despite challenges, brain plasticity allows for potential in creating non-invasive brain-machine interfaces (BMIs) for enhancing abilities, but advanced technology is needed to access signals at the single neuron level
The brain's plasticity and flexibility are remarkable. Researchers have shown that even areas of the brain not typically associated with movement can be trained to perform new tasks using a non-biomimetic approach. This flexibility is intriguing, and some visionaries like Elon Musk envision a future where brain-machine interfaces (BMI) are used for enhancing abilities rather than just aiding those with disabilities. However, we're not quite there yet. To create an effective non-invasive BMI, we need to access signals at the level of single neurons or small groups of neurons, which requires advanced technology that doesn't currently exist. While there are companies working on minimally invasive solutions, the idea of widespread non-invasive brain surgery remains a significant hurdle.
Brain-machine interfaces: Researchers are investigating minimally invasive methods for creating brain-machine interfaces, including direct skull implants and blood vessel implants. While the latter shows promise, its effectiveness is uncertain, and current research focuses on enhancing BMIs with sensory feedback to improve user experience.
Researchers are exploring minimally invasive approaches to develop brain-machine interfaces (BMI) by using electrodes. One method involves making a small incision in the skull to place electrodes directly on the brain, while another approach, by Synchron, attempts to implant electrodes through blood vessels and record signals from the brain. However, the latter method's effectiveness is uncertain as it doesn't get electrodes close enough to neurons. Current research priorities focus on enhancing BMIs with sensory feedback, particularly touch and proprioception, to improve interaction with objects and normal movement for individuals with motor disabilities.
Brain-Computer Interfaces: Researchers are developing bi-directional brain-computer interfaces that can restore both motor function and the sense of touch for individuals with motor injuries, allowing realistic interaction with objects and preventing damage.
Researchers are making significant strides in developing bi-directional brain-computer interfaces that can restore not only motor function but also the sense of touch for individuals with motor injuries. Currently, two human subjects at the University of Chicago and the University of Pittsburgh have electrodes implanted in their motor and somatosensory cortices, allowing them to feel tactile sensations on their fingertips as they control robotic hands. This technology, which goes both in and out of the brain, opens up possibilities for subjects to experience a realistic interaction with objects, preventing damage or breakage. Additionally, there are ongoing efforts to develop prosthetic eyes, with several approaches under exploration, including stimulating the retina, cortex, or thalamus. While a commercial product is not yet available, progress is being made.
Neural prosthetics: Researchers are developing neural prosthetics to restore sensory functions through direct brain communication, offering significant benefits for individuals with disabilities, despite slower progress compared to technologies like cochlear implants.
Neural prosthetics, while still in development, hold great promise for individuals with disabilities. Researchers like Dr. Hatsapalis are working to create devices that can restore sensory functions, such as touch and hearing, through direct communication with the brain. Although progress has been slower than with technologies like cochlear implants, the potential benefits are significant. If you're interested in learning more about this exciting field, check out the July issue of APA's Magazine Monitor on Psychology at www.apa.org. Remember, Speaking of Psychology is available on various platforms including our website, Apple, Spotify, YouTube, and wherever you get your podcasts. Don't forget to leave a review if you enjoy the show. And if you have ideas for future episodes, feel free to email us at speakingofpsychology@apa.org. Speaking of Psychology is produced by Lee Weinerman. Thanks for tuning in, and stay curious!