Science, Technology Assessment, SEPTEMBER 2022 and Analytics WHY THIS MATTERS Brain-computer interfaces allow people to control machines using their thoughts. These interfaces can SCIENCE & TECH SPOTLIGHT: help people with disabilities as well as enhance human- BRAIN-COMPUTER computer interactions. For example, warfighters might operate a drone hands-free on the battlefield. However, the technology remains largely experimental, and it INTERFACES raises questions about security, ethics, and equity. /// THE TECHNOLOGY Some implanted BCIs reduce risk by placing electrodes on the surface of the brain, a method called electrocorticography (ECoG). What is it? A brain-computer interface (BCI) enables a person to control an external device using brain signals. BCIs could aid people with Wearable BCIs often require a cap containing conductors that measure disabilities and improve national defense capabilities, among other uses. brain activity detectable on the scalp. A wearable BCI may be appropriate For example, researchers are developing BCIs that allow people with for purposes like augmented and virtual reality, gaming, or controlling an paralysis to spell words on a computer screen or regain control of their industrial robot. Most wearable BCIs use electroencephalography (EEG) limbs. In addition, researchers are developing BCI-controlled robotic limbs to measure the brain's electrical activity. An emerging method-functional that can provide users with a sense of touch. BCIs could also augment near-infrared spectroscopy (fNIRS)-shines near-infrared light through the human capabilities by allowing people to control computerized machinery skull to measure blood flow, which can indicate information such as the using their thoughts, for example (see fig. 1). user's intentions. To enhance mobility, researchers are developing BCIs that use portable methods to acquire data-for example, wireless EEG. These methods allow users to operate a smartphone or other device while moving freely. Figure 2. Examples of implanted (left) and wearable (right) BCIs. Figure 1. Examples of BCI applications include a speller for communication, a smartphone interface, a BCI-operated drone, and a robotic limb. How mature is it? Most BCIs are experimental. Researchers first tested a wearable BCI in the early 1970s and implanted a BCI in a human for the How does it work? New BCI users often undergo an iterative training first time in the late 1990s. BCI research has increased significantly in the process. The user learns to produce signals the BCI will recognize, and 21st century resulting in the publication of thousands of research papers. the BCI translates the signals to operate a device using machine learning. According to one leading BCI company, fewer than 40 people worldwide have implanted BCIs, all of them experimental. One of the main obstacles Generally, BCIs connect to the brain in two ways: through implanted to BCI development is that each person generates unique brain signals. or wearable devices (see fig. 2). Implanted BCIs are often surgically Another is the difficulty of measuring those signals. attached directly to brain tissue. They may be more appropriate for users with severe neuromuscular disorders or physical injuries. For example, Historically, BCI research has focused on biomedical applications, such a person with paralysis could use an implanted BCI that is attached as helping people disabled by a stroke, physical injury, or neurological to specific neurons to regain precise control of a limb. Implanted BCIs disorder. In April 2021, a device that uses a wireless EEG headset to help measure signals directly from the brain, reducing interference from other stroke patients regain arm and hand control became the first wearable tissue. However, they pose surgical risks, such as infection and rejection. BCI for rehabilitation to receive market authorization from the Food and GAO-22-106118 Brain-Computer Interfaces Science, Technology Assessment, and Analytics Drug Administration. A number of other wearable and implanted BCIs for /// CHALLENGES medical uses are currently in clinical trials. ■ Technical and user challenges. Each person generates unique Researchers are also developing applications for military use and for brain signals, which are difficult to measure clearly. Also, learning to systems whose proper operation is critical to safety. For example, use a BCI can require substantial training. researchers at the National Aeronautics and Space Administration have used BCIs to help detect when pilots and air traffic controllers are more ■ Ethical framework. BCIs may raise questions about what likely to make mistakes. The Department of Defense has funded research constitutes consent and about potential unfair advantages conferred on BCIs for hands-free control of drones. And the Federal Aviation by certain human enhancements. Administration has looked into how to medically certify pilots who may one ■ Security and privacy. BCIs could be vulnerable to cyberattacks that day use BCIs to control airplanes. expose brain data or interfere with a device's function. What are some concerns? Some researchers have noted possible /// POLICY CONTEXT AND QUESTIONS legal and security implications of BCIs. For example, cyberattacks are a concern because hackers could use malware to intercept brain signal ■ As BCIs develop toward commercial and patient use, will they be data stored on a smartphone. The Department of Commerce is currently accessible to all, and who will bear the cost? reviewing whether exporting BCIs could pose national security concerns. ■ How should BCIs that augment human capabilities be regulated, if For example, foreign adversaries could obtain a military or intelligence at all? advantage. Its decision could affect how the technology is used and shared overseas. ■ What ethical issues might BCIs raise, and what applications might constitute unethical or controversial use of BCIs? Researchers have also pondered societal and ethical implications. Reported costs of wearable BCIs range from hundreds to thousands ■ What steps might help to mitigate potential security and privacy risks of dollars, which may result in unequal access. Additionally, learning associated with the acquisition of brain signal data? to use some types of BCIs requires training, which may burden users. /// SELECTED GAO WORK Researchers have also suggested that translation of brain signals to speech by a BCI could cause harm if it is not accurate. For example, Science & Tech Spotlight: Extended Reality Technologies, inaccurate translation might indicate legal or medical consent that the GAO-22-105541. person did not intend to give. /// SELECTED REFERENCES /// OPPORTUNITIES RAND Corporation. Brain-Computer Interfaces: U.S. Military Applications and Implications, ■ Help people with disabilities. People paralyzed by physical injuries an Initial Assessment. RR-2996-RC. Santa Monica, CA: 2020. or neurological disorders could use BCIs to communicate and regain control of their limbs. U.S. Department of Health and Human Services. Food and Drug Administration. Center for Devices and Radiological Health. Implanted Brain-Computer Interface (BCI) Devices ■ Augment human capabilities and human-computer interactions. for Patients with Paralysis or Amputation - Non-clinical Testing and Clinical Considerations: BCIs could accelerate and simplify interactions between humans and Guidance for Industry and Food and Drug Administration Staff. FDA-2014-N-1130. Rockville, machines in fields like defense and space. Also, some researchers MD: 2021. have suggested that BCI-controlled robots could assist people in hazardous environments, such as coal mines. U.S. Department of Transportation. Federal Aviation Administration. Office of Aerospace ■ Facilitate brain research. Scientists could use BCIs to improve Medicine. Medical Certification Strategies in Response to Technologically Advanced understanding of the brain. Some researchers have used a BCI Prosthetic Devices. DOT/FAA/AM-18/7. Washington, DC: 2018. to detect the emotions of patients in a vegetative or minimally conscious state. 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This work of the United States may include copyrighted material, details at www.gao.gov/copyright. Staff Acknowledgments: Richard Hung (Assistant Director), Cheryl Harris (Analyst-in- Charge), Nora Adkins, Nicole Catanzarite, Joe Rando, and Ben Shouse. GAO-22-106118 Brain-Computer Interfaces