Hybrid / multimodal wearable BCI

A system that fuses more than one information source to gain robustness or complementary information the single stream cannot provide. The fusion can be across neural modalities (EEG with fNIRS, exploiting the electrical signal's speed and the optical signal's motion tolerance), across paradigms (combining a P300 response with steady-state visual evoked potentials or motor imagery), or across neural and non-neural sensors (adding inertial units, heart rate, eye tracking, or electromyography to catch artefacts or provide an auxiliary control channel).

The rationale is that failure modes are often uncorrelated: when contact degrades on the EEG, the optical or inertial channel may still be informative, and a confidence measure can arbitrate. Multimodality is one of the more credible routes to out-of-the-lab reliability, but it is not free — more sensors mean more setup, more power, tighter synchronisation, and more ways for a component to fail, so the added modality has to earn its place with a measured gain, not merely be present.