What is a Brain-Computer Interface (BCI)?

From the Guidelines

A Brain-Computer Interface (BCI) is a technology that enables people to control devices with their thoughts, using brain signals detected through methods like electroencephalography (EEG) or invasive electrodes, and has significant applications in helping individuals with motor disabilities regain independence. BCIs work by processing brain signals into commands for connected devices, allowing people to control computers, prosthetic limbs, or other machines using only their thoughts 1. The technology relies on the electrical impulses that neurons in the brain use to communicate, creating detectable patterns that correspond to different thoughts or intended movements. While current BCIs are primarily used in medical and research settings, future developments may expand their use to enhance human capabilities or create new forms of human-computer interaction in everyday life.

Key Points

• BCIs have significant applications in helping people with paralysis, ALS, or other motor disabilities regain independence by controlling wheelchairs, communication devices, or robotic limbs.
• The technology works because neurons in our brain communicate through electrical impulses, creating detectable patterns that correspond to different thoughts or intended movements.
• Current BCIs are primarily used in medical and research settings, but future developments may expand their use to enhance human capabilities or create new forms of human-computer interaction in everyday life.
• There is insufficient evidence to recommend for or against the use of non-invasive brain-computer interface to improve upper extremity motor outcomes and activities of daily living, as stated in the 2024 U.S. Department of Veterans Affairs and U.S. Department of Defense clinical practice guidelines 1.

Considerations

• The development of BCIs should incorporate co-design principles, engaging intended users in the design and development of products to meet patient and therapist needs and maximize therapeutic outcomes.
• The use of BCIs in rehabilitation settings, such as for stroke or acquired brain injury, may have potential benefits, but the current evidence base is limited and more research is needed to fully understand their effectiveness.

From the Research

Definition of Brain-Computer Interface

• Brain-Computer Interfaces (BCIs) are systems that acquire brain signals, analyze them, and translate them into commands that are relayed to output devices to carry out desired actions 2.
• BCIs aim to help paralyzed patients interact with their environment by controlling external devices using brain activity, thereby bypassing the dysfunctional motor system 3.
• The main goal of BCI is to replace or restore useful function to people disabled by neuromuscular disorders such as amyotrophic lateral sclerosis, cerebral palsy, stroke, or spinal cord injury 2.

Types of Brain-Computer Interfaces

• Invasive BCIs use electrodes implanted directly into the brain to record brain activity 4.
• Non-invasive BCIs use techniques such as electroencephalography (EEG), functional near-infrared spectroscopy (fNIRS), and electrocorticography to record brain activity 3, 4, 5, 6.
• Partially invasive BCIs use electrodes implanted into the skull but not directly into the brain 4.

Applications of Brain-Computer Interfaces

• BCIs can be used to provide a means of communication for patients with severe motor disabilities, such as those with amyotrophic lateral sclerosis (ALS) or locked-in syndrome (LIS) 3, 4, 5.
• BCIs can be used to control external devices such as cursors, robotic arms, prostheses, wheelchairs, and other devices 2.
• BCIs may also prove useful for rehabilitation after stroke and for other disorders 2.

Techniques Used in Brain-Computer Interfaces

• Electroencephalography (EEG) is a non-invasive technique that records brain activity through electrodes placed on the scalp 3, 4, 5.
• Functional near-infrared spectroscopy (fNIRS) is a non-invasive technique that measures localized cortical brain activity using near-infrared light 5, 6.
• Electrocorticography is a partially invasive technique that records brain activity through electrodes implanted into the skull 4.