The beginner’s guide to how to get your own EEG brain-computer interface (BCI)
Opportunities to get, configure, and use an EEG-based BCI are better than ever. Wireless EEG-based systems that use dry electrodes are increasingly practical. Price, cosmesis, wearability, and signal quality in noisy real-world settings are improving. Manufacturers have recently begun selling systems that are meant to be used by people without prior experience with EEGs or BCIs. Many online mechanisms to learn like discussions, exercises, walk-throughs, lectures, technical guides, and support fora are available (e.g., Allison et al., 2020 [Psychophysiology]).
Scope of this guide
1. This is not an intro to BCIs in general. This is for people who want to obtain their own working BCI. This will require several hours and more commitment than just learning about BCIs.
2. BCIs are devices that read from, not write to, the brain. Many of us recognize this acronym can be misleading, but that’s the canonical definition (e.g., Kuebler et al., 2001; Wolpaw et al., 2002; Allison et al., 2007; Pfurtscheller et al., 2010; Wolpaw and Wolpaw, 2012; Nijboer et al., 2013; Nam et al., 2018).
3. This is not a journal-quality document — for example, I provide only parenthetical references.
4. This is a friendly guide is for non-invasive BCIs for casual use. I hope that some readers develop ideas that could help patients, but that entails challenges beyond this guide.
5. I present disclaimers at the end. I’m involved with various entities and references here. I avoid mentioning specific companies and products but instead provide info to help you choose.
Practice online first
You can practice many BCI activities online before spending money. You can download sample EEG data, use different tools to view and analyze the data, explore the effects of different band-pass and spatial filters, artifact detection and removal algorithms, classifiers, and outputs including cursor control, spelling, web browsing and gaming. You can also find tools to manage stimulus presentation, time-locking, and BCI-based user interfaces. Online guides and chatrooms also have examples of introductory-level exercises you can perform with pre-recorded data. Try tasks like identifying power at different frequencies, creating ERP epochs, identifying P300s, comparing offline classification accuracy with different approaches, developing clever user interfaces, and controlling different outputs. Look at examples of how other people solved similar problems with BCIs. Is this fun for you? Do you want more? Then get a BCI. Otherwise, don’t.
There are many different online options with free EEG data and BCI software tools. Examples include BCI2000, EEGLab, OpenBCI, OpenVibe, and BCI++. While dated, Brunner et al. (2013) overviews different software platforms that are still good options today. Many companies also have software tools and guides for their BCI systems, some of which are online for free. Classic papers that reference BCI data analysis competitions include Sajda et al. 2003, Blankertz et al. 2006, and Tangermann et al. 2012. Prof. Gao’s group did very well in these early BCI competitions, and her group published some good papers with their methods.
Buy your own BCI
There are many guides to this decision, most written by someone who (unlike me) expects to profit from that guide. Consider:
1) Who wrote the other guide? There’s a lot of hype out there. If they stand to profit from selling the BCI, that doesn’t disqualify them; there are reputable companies who sell BCIs. But, you should try to find some objective sources as well. A proven track record of success making working BCIs means a lot to me. If you never built a working BCI, you should do so before writing a guide.
2) Peer-reviewed papers in good journals. The methods section of these papers will mention the system and manufacturer they used. This means that experts in the field, who were able to get a paper published in a good journal, chose that system.
3) Price. Many systems in journal papers are medical-grade systems that cost thousands of dollars. If you just want to tinker with a BCI at home, you can use a much expensive system. On the other hand, systems that cost around $100 are often single-channel devices that rely largely on EMG and make iffy promises. No, you cannot make an EEG system with your stereo amplifier.
4) EMG. Are you sure you’re buying a system that records your EEG? Some manufacturers claim their system provides EEG when they know they are lying. A system that relies only on indirect measures is not a BCI, though it may be called a BNCI. See, for example, http://bnci-horizon-2020.eu/images/bncih2020/FBNCI_Roadmap.pdf.
5) Hybrid BCIs. Maybe you’re interested in non-EEG signals. Many BCIs have been combined with other devices that sense activity from the eyes, heart, muscles, etc., and I am as bullish on hybrid BCIs as ever. Choose whether non-brain signals are important and consider this when buying a system. Can the amplifier work with non-EEG signals?
6) Objective online evidence of system usage. Do other people like you post questions online? Do they get helpful replies — and if so, who answers (e.g., the manufacturer, students, professors, other users, etc.)? What do other users say about their experiences? Have you seen examples of “success stories” with students or others who developed a working BCI with that system?
7) Websites with BCI hackathons. These are (or were, before COVID) public, interactive events where teams of students got a BCI system and built a working BCI in 24 hours or so. We often have a jury that judges the resulting BCIs, and then we give the winning team a certificate. From the websites, you can find out which systems they used, what kinds of BCIs they developed, what the jury thought was the best project, etc. I really miss BCI hackathons.
8) Nearby (or remote) available experts. If you’re a student, ask your TA, professor, or a friendly expert for advice. If you see people posting online who seem knowledgeable and tend to reply to questions, ask for advice. Look at other guides.
9) Try before you buy? Your university might have a BCI in a lab on campus, or a nearby maker lab might have one. This leads to the next section.
Use a BCI that you don’t own
This section was more feasible before COVID, and I hope that options to try out someone else’s BCI return after pandemics are less of a concern. Using someone else’s BCI can be a great way to find out if you like a specific BCI system, and whether you want to devote more time to tinkering with BCIs. Here are some options:
1) University systems meant for BCIs. Universities often have labs with devices, systems, chemicals, etc. that are meant for student use. Someday, there will be BCI systems that students can use in most universities just like a microscope with slides, Arduino kit, chemistry set, etc. Departments like neuroscience, psychology, computer science, and various engineering departments might get a BCI if many students are interested. Right now, there aren’t many systems dedicated to BCI use at universities. However, turning a brain imaging system into a BCI might be easy….
2) University brain imaging courses and internships. Your university might have an EEG system or other device for imaging the brain such as fNIRS or MRI. Find out who works with the system. Look at their research, the people in their lab, and courses they teach. Some manufacturers have student interns as well, usually PhD students. Maybe they aren’t primarily focused on using their tools and people for BCI applications, but they would be if they had a good student with sound ideas.
a. Please don’t contact labs or companies unless you’ve really taken time to study them and think you are a good fit for them. We get generic emails all the time.
b. If your request involves them paying for flights and housing, they’ll probably say no. They probably have great choices from nearby universities and don’t have extra money for these costs.
c. Getting angry at us won’t help. I presently have no: funding whatsoever; grant applications under review; lab; in-person students; available BCI; personal money.
3) Maker spaces. BCIs are not currently prominent there, but could be in several years. Like universities, owners should and will get a BCI if they think many people will use one.
4) Non-profit entities. Some chapters of local BCI-friendly non-profit entities such as NeuroTechX may have one or more BCIs. They might let you try out their system.
5) Ask for a free system. I’ve seen this hundreds of times. It very rarely works. I’ll be more specific. I’ve never seen it work with a university or hospital. Manufacturers might provide a loaner if they really think you are a likely future buyer.
I am an author on many of the papers referenced here. I don’t receive royalties from any source.
I have consulted for g.tec and NCAN (Natl. Center for Adaptive Neurotech). I visited Facebook HQ in Jan 2019 and gave an in-person talk for Microsoft in Feb 2020, but wasn’t paid for either of these. You can find other information about my affiliations online.
Nobody paid me for this article. I haven’t been paid by UCSD in over 15 years. I just wanted to encourage people who want to tinker with BCIs and use them to help people. Like me.
This is a single-author document. I alone am responsible for its content. I have never submitted this document for peer-reviewed publication. I may post updated versions here or elsewhere.
Brendan Z. Allison, PhD.
“The BCI Guy”