Brain–computer interface (BCI) technologies are making headlines. In November, for example, IEEE Spectrum pointed to in-situ use of interface devices that let paralyzed patients control tablets with their thoughts alone.
Let’s tackle the basics of this mind over matter machinery — How does a BCI work? What else can this technology do? — and consider the key challenges of unlocking human potential.
Interface in Action
There’s capital for the BCI market; Medgadget notes a predicted 11 percent compound annual growth rate over the next five years as medical technology companies look for ways to translate evolving brain science into marketable devices.
But what exactly is a brain–computer interface? How does a BCI work? The National Center for Biotechnology Information (NCBI) offers a concise explanation: “Brain–computer interfaces (BCIs) acquire brain signals, analyze them, and translate them into commands that are relayed to output devices that carry out desired actions.” The primary goal of these devices? To assist patients with neuromuscular disorders by enhancing or replacing useful motor functions and other actions.
Once the realm of science fiction, an improved understanding of brain pathways and functions makes it possible for BCIs to “translate” simple commands that are then relayed to output devices via microelectrode arrays and sensors installed into specific areas of the brain related to hand movement, hand-eye-coordination or speech. Initial efforts allowed users to select letters from a screen to spell simple words, which were spoken aloud by a synthesizer — as noted by Scientific American, famed cosmologist Stephen Hawking used a system of this type. First-generation BCIs were often unwieldy, requiring multiple cables, large signal receiver boxes and substantial user training to ensure accuracy and reliability. More investment in BCI is now driving greater patient uptake and improvements to device functionality.
A new research initiative from Stanford University, known as “BrainGate,” recently demonstrated that BCI devices can be used by tetraplegic people to control commercial tablets. According to Discover, this brain–computer interface can decode brain activity associated with hand movement, which is then transmitted to a Bluetooth interface controlling a virtual mouse. Trial subjects said the BCI-tablet connection became “second nature” — one participant shopped for groceries online, another texted friends and family and the third was able to create music on a digital keyboard.
Also in development? Speech BCI. As Scientific American points out, electrode degradation and technology limitations hampered previous attempts, which often struggled to interpret the “silent” speech of brain connections with more than 40 percent accuracy. New research out of Columbia University and the Feinstein Institute for Medical Research, however, has been able to reliably achieve 75 percent intelligibility.
So what’s holding BCI back? According to the NCBI, there are three main challenges:
- Hardware: BCIs need hardware “that is convenient, portable, safe, and able to function in all environments.”
- Testing: Brain–computer interfaces must be validated across long-term studies using real-world patients to develop viable new use models.
- Reliability: Interface technology must develop to a point where performance “approaches the reliability of natural muscle-based function.”
Other challenges include the invasive nature of implanting microelectrode arrays (MEAs) into brain tissue, the natural degradation of these MEAs over time — within a year, most begin to fail — and the potential for bacterial or viral infection after repeated MEA surgeries.
Despite the challenges, however, optimism in the field remains high, and new research continues to produce results. According to Science Daily, current areas of focus for BCI include “brain-controlled, computer-guided hand movements” that may empower electrical-stimulation–based prosthetics, visual and electronic feedback for stroke patients to help recover motor function and the use of new techniques such as “dynamic current steering,” which can restore limited vision to blind people.
Mobile device control, artificial limb movement and adaptive speech translation were the stuff of science fiction ten years ago. Now, new brain–computer interface technologies are harnessing the power of the mind over matter to deliver untapped human potential.