Background: A brain-computer interface (BCI) may be broadly defined as a computer-based system that acquires brain signals, analyzes them, and translates them into commands that are relayed to an output device to carry out a desired action. BCI technology was initially envisioned as a health care technology that could increase individuals' mobility and independence. However, the research applications of BCI technology have evolved significantly over the years, expanding to include various commercial applications. The rapid development of BCIs for larger target audiences raises concerns about the ethics, safety, security, and privacy of devices. Key Questions: 1) What brain-computer interface technologies are available or in development and what are their potential benefits? 2) What challenges could affect the development and use of these technologies? 3) What options could policymakers consider to enhance the benefits or mitigate the challenges associated with this technology?