Brain-computer interfaces (BCIs) enable communication between the brain and the external environment, showing significant potential in restoration, rehabilitation and movement enhancement. However, neural drift causes BCI performance to degrade substantially over time, compromising their long-term reliability. A fundamental limitation of current methods is their failure to account for a key insight from neural preference theory that the magnitude of neural drift depends on specific motor parameters (e.g., velocity, direction, and speed), ultimately compromising performance. To overcome the limitation, we introduce a novel framework named ComplementaryDisentangled Neural Generalization (CDNG) inspired by neural preference theory. Specifically, we first conduct pre-experiments about the neural decoding preference, revealing that neural drifts differ across velocity, speed and direction. Then we adopt CDNG, which captures invariant neural representations through an ensemble of three specialized neural decoders after disentangling velocity into speed and direction. Extensive experiments on several datasets demonstrate that our method achieves state-of-the-art performance and significantly enhances cross-day generalization.

Brain-computer interfaces (BCIs) offer a means to convert neural signals into control signals, providing a potential restoration of movement for people with paralysis. Despite their promise, BCIs face a significant challenge in maintaining decoding accuracy over time due to neural nonstationarities. While current recalibration techniques address this issue to a degree, they either fail to adequately exploit the limited labeled data, fail to perform conditional alignment in regression tasks, or overlook the signal correlation between data from two days. This paper proposes a novel Speed-enhanced Subdomain Alignment (SeSA) framework, integrating semi-supervised learning with domain adaptation techniques in regressive neural decoding. Specifically, SeSA carries out two alignments (i.e., global alignment and conditional speed alignment) to achieve recalibration. Our comprehensive set of experiments, both qualitative and quantitative, substantiate the superior recalibration performance and robustness of our proposed SeSA.

Neural signals are typical nonstationary data where the functional mapping between neural activities and the intentions (such as the velocity of movements) can occasionally change. Existing studies mostly use a fixed neural decoder, thus suffering from an unstable performance given neural functional changes. We propose a novel evolutionary ensemble framework (EvoEnsemble) to dynamically cope with changes in neural signals by evolving the decoder model accordingly. EvoEnsemble integrates evolutionary computation algorithms in a Bayesian framework where the fitness of models can be sequentially computed with their likelihoods according to the incoming data at each time slot, which enables online tracking of time-varying functions. Two strategies of evolve-at-changes and history-model-archive are designed to further improve efficiency and stability. Experiments with simulations and neural signals demonstrate that EvoEnsemble can track the changes in functions effectively thus improving the accuracy and robustness of neural decoding. The improvement is most significant in neural signals with functional changes.