Causal Reasoning in Brainwave Modeling: Advancing BCIs from Lab Research to Real-World Use

Significance 

Brain-computer interfaces (BCIs), are paving the way toward a future where people might control devices just by using their thoughts. The possibilities are thrilling—think about someone with a disability regaining control of their limbs, or even a world where we can communicate with machines in entirely new ways. But despite the excitement, getting BCIs to work outside of the lab has proven tricky. One big issue is that brainwaves are complex, and making sense of them in real-world settings is far from easy. Machine learning and deep learning have propelled fields like image recognition and natural language processing forward, yet these techniques don’t entirely solve the unique challenges that BCIs face. BCIs have a few major stumbling blocks right now. First, the quality of brainwave data isn’t always consistent. This makes it tough to build models that can work reliably for different people and environments. Plus, there’s a shortage of well-labeled datasets, which are critical for training these models. Brainwaves are incredibly individualized; subtle differences like age, gender, and the EEG device used can cause big variations. This means that what works well for one person might not work at all for another. Brainwave data also tends to be noisy, which complicates things further. If these issues aren’t tackled, there’s a real risk that BCIs will stay stuck as a research project, rather than becoming tools that people can actually use day-to-day.

Seeing these obstacles, in recent research paper [1] published in Journal of Neural Engineering and led by PhD candidate Konstantinos Barmpas, Yannis Panagakis, Georgios Zoumpourlis, Dimitrios Adamos, Nikolaos Laskaris, and Professor Stefanos Zafeiriou from the Department of Computing at Imperial College London and Cogitat (an Imperial spinout company), the researchers are exploring how something called causal reasoning might offer a way forward. They’re curious if understanding the deeper cause-and-effect relationships in brainwave data could help overcome some of the limitations that standard machine learning approaches face. While machine learning can be excellent at spotting patterns, it often struggles when conditions change, like when data from one group needs to be applied to a different group or when the environment isn’t exactly the same. By bringing causal reasoning into the picture, the researchers hope to make models that aren’t just good at finding patterns but are also better at adapting to new situations.

Their study is driven by the hope that causal reasoning can bridge the gaps where machine learning alone falls short. By digging into how different factors actually cause changes in brainwave patterns, they’re aiming to create a framework that doesn’t just improve accuracy but also lays the groundwork for future progress in BCI technology. Ultimately, they want to make BCIs more versatile and reliable, so they can step out of the lab and into the real world where they could truly make a difference. The research team set out to see if adding causal reasoning could actually make brainwave models for BCIs smarter and more reliable. To do this, they started by breaking down BCI tasks into two main categories: those involving external stimuli (like visual or auditory signals) and those that don’t rely on any outside triggers. They also looked at whether the brain activity in each task was something the user consciously controlled or if it just happened naturally. This setup helped them see how different BCI types work and where causal links could make a difference. In their experiments, they looked at both types of tasks: ones driven by outside stimuli and others that come purely from internal thought. For example, the authors analyzed motor imagery, where someone imagines moving their hand (an internally controlled task), and P300 responses, which happen when the brain reacts involuntarily to something it sees or hears. They wanted to see how these different tasks shape brainwave patterns and how understanding the underlying causes might help make sense of the data in new ways. One thing they found right away is that traditional machine learning models often stumble when they’re faced with data collected under different conditions. This is a common problem since brainwave data can vary a lot depending on things like the person’s age, the device used, or even the time of day. By drawing out cause-and-effect maps of the relationships between the task, the brainwave signals, and any outside stimuli, they could anticipate these data shifts. They found that when models take these causal relationships into account, they become much better at adapting to different settings, which is a big deal for making BCIs usable in the real world. Another important part of their research was dealing with noise in the data. Brainwave signals are easily affected by all kinds of interference, whether it’s from muscle movements or outside factors like lights or sounds. They also found that including causal factors helped the models handle differences between people more effectively. Every person’s brain works a little differently, and even slight variations in brain structure or function can throw off standard models. But by accounting for these individual differences, the causal models were able to adjust to new subjects without having to start from scratch [2]. This adaptability is crucial if we want to move BCIs from labs to everyday use. In the end, their research suggests that by understanding the cause-and-effect behind brainwave data, we could make BCIs more resilient, versatile, and ready for real-world applications [3].

The study of Konstantinos Barmpas et al is really something different for BCIs. Instead of sticking with the usual machine learning methods, which can often fall short when things get messy, the researchers are using causal reasoning to make BCIs better at handling real-world unpredictability. Traditional models often struggle when faced with the kinds of variability you find in day-to-day life, like changes in environment or differences between people’s brain patterns. By bringing in causal reasoning, this research opens up a new way to create BCIs that don’t just work in a lab but can actually adapt to all those real-world quirks. We believe one of the most exciting parts of the new study is how it could make BCIs more useful in practical settings, like clinics or assistive technologies. Picture a BCI that can actually adjust to help someone with a disability communicate or control a device, no matter where they are or what’s happening around them. The framework they’re proposing could even pave the way for BCIs that are personalized [4], so they respond to each person’s unique brain patterns. It’s the kind of advancement that could make BCIs feel a lot more intuitive and, honestly, a lot more usable in everyday situations. What’s also interesting is that this work isn’t just limited to BCIs. By showing how causal reasoning can make these models more robust, the researchers are hinting at a broader impact on artificial intelligence in general. This method could be useful in any field where data changes rapidly and unpredictably, like healthcare or self-driving cars. The approach might inspire others to try similar techniques, especially in areas where being able to predict and adapt is critical but really hard to get right. And beyond the immediate results, this study gives a roadmap for where things could go next. It’s not just about making BCIs more reliable now; it’s about setting the stage for further exploration. As technology advances, this framework could get even more sophisticated, maybe even letting us understand brainwave patterns in ways we haven’t been able to before. In the long run, it’s a step toward making BCIs more versatile, so they’re actually ready to face the challenges of the real world. And that could mean a big leap forward in how we think about using BCIs in all kinds of practical applications.

About the author

Konstantinos is a final year PhD student in Machine Learning / Brain-Computer Interfaces (BCIs) at the Department of Computing, Imperial College London, under the supervision of Prof. Stefanos Zafeiriou. His main research interests lie in the intersection of Deep Learning and Brain-Computer Interfaces (e.g., Differentiable Signal Processing, Geometric Deep Learning, Causality).

He has also been working as a Machine Learning Engineer at Cogitat where he has been developing novel deep learning methods for EEG-based Brain Computer Interfaces (BCIs). Their groundbreaking decoding brainwave technology was featured by British Computing Society, Sky News, BBC, The Times, Telegraph, New Statesman, Sifted, and Business Insider among others.

During his PhD, he is also an Academic PhD Student Representative for the Department of Computing (Imperial College London), Main Organizer of Imperial Computing Conference (ICC), Co-Organizer of London Geometry and Machine Learning (LOGML) Summer School, Member of the Equity, Diversity and Culture Committee (EDCC) for the Department of Computing (Imperial College London), a Lakera AI Student Momentum Ambassador and a Microsoft Student Ambassador.

Prior to joining the Department of Computing as a PhD student, he completed my Master of Engineering at the Department of Electrical and Electronic Engineering, Imperial College London. He undertook his Master’s year at ETH Zürich as a visiting student where he conducted his Master Thesis at the Data Analytics Lab under the supervision of Prof. Thomas Hofmann.

References

[1]: Barmpas K, Panagakis Y, Zoumpourlis G, Adamos DA, Laskaris N, Zafeiriou S. A causal perspective on brainwave modeling for brain-computer interfaces. J Neural Eng. 2024 May 3;21(3). doi: 10.1088/1741-2552/ad3eb5.

Go to J Neural Eng.

[2]: Barmpas K, Panagakis Y, Adamos DA, Laskaris N, Zafeiriou S. Improving Generalization of CNN-based Motor-Imagery EEG Decoders via Dynamic Convolutions. IEEE Transactions on Neural Systems and Rehabilitation Engineering, 2023 doi: 10.1109/TNSRE.2023.3265304

Go to IEEE Transactions on Neural Systems and Rehabilitation Engineering

[3]: Cogitat Demo | Mind Controlled Games at Imperial College Lates Event: https://www.youtube.com/watch?v=4TgGcINt1SM

[4]: Barmpas K, Panagakis Y, Adamos DA, Laskaris N, Zafeiriou S. BrainWave-Scattering Net: A lightweight network for EEG-based motor imagery recognition. Journal of Neural Engineering, 2024. doi: 10.1088/1741-2552/ad3eb5

Go to Journal of Neural Engineering

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