Authors: Milán András Fodor, Ivan Volosyak
Accompanying code repository for our SMC 2025 submission:
Towards Visual-Fatigue-Free BCI with Imperceptible Visual Evoked Potentials (I-VEP)
A Brain–computer interface (BCI) enables direct control of external devices through neural activity. Among BCI paradigms, visual evoked potentials (VEPs) are widely used because they harness the brain’s response to visual stimuli to deliver an intuitive and inclusive control interface. However, these systems typically rely on low-frequency flickering stimuli to evoke strong neural responses, which can cause discomfort and fatigue. While previous work has sought to mitigate this discomfort, eliminating it entirely would be ideal.
High-frequency flickering—operating above the critical fusion frequency threshold and thus invisible to the human eye—has been shown to be distinguishable from low-frequency or non-flickering stimuli, offering a promising alternative. However, reliably differentiating between two high-frequency codes remains challenging.
Our novel Imperceptible VEP (I-VEP) paradigm combines invisible high-frequency flicker segments with static (non-flickering) intervals to create neural response patterns analogous to both steady-state VEPs (SSVEPs) and code-modulated VEPs (cVEPs). We define two variants:
- Imperceptible Steady-State VEP (I-SSVEP)
- Imperceptible Code-Modulated VEP (I-cVEP)
Our initial I-cVEP experiments demonstrate the feasibility of these approaches. The scripts and code used for these experiments are in the process of being uploaded and updated in this repository.