Optimization of Dynamic SSVEP Paradigms for Practical Application: Low-Fatigue Design with Coordinated Trajectory and...

Area of Science:

• Neuroscience
• Human-Computer Interaction
• Biomedical Engineering

Background:

• Steady-state visual evoked potential (SSVEP) is a reliable BCI method.
• Static visual stimuli in SSVEP can lead to user discomfort and reduced engagement.
• Novel dynamic stimuli are needed to enhance user experience in SSVEP-based BCIs.

Purpose of the Study:

• To develop and evaluate a dynamic SSVEP stimulation paradigm using periodic motion trajectories and speed control.
• To assess the impact of dynamic stimuli on accuracy, cognitive workload, and user experience.
• To explore the potential for fatigue-resistant and user-friendly BCI applications.

Main Methods:

• Investigated dynamic stimulation with varying frequencies (6-12 Hz) and waveform patterns (sinusoidal, square, sawtooth).
• Modulated stimulus speed relative to base frequencies (1/5, 1/10, 1/20).
• Conducted offline experiments (n=17) for accuracy and cognitive workload assessment, and online experiments (n=12) using a BCI game.

Main Results:

• Low-speed sinusoidal and sawtooth dynamic stimuli achieved accuracy comparable to static stimuli (85.84% and 83.82%).
• Dynamic stimuli reduced cognitive workload by 22% in offline tests.
• Online experiments demonstrated practical application with >82% accuracy and high usability (SUS score 75.96).

Conclusions:

• Coordinated trajectory and speed modulation in SSVEP paradigms maintain signal quality.
• Dynamic SSVEP stimulation enhances user experience and comfort.
• This approach offers a promising direction for developing fatigue-resistant, user-friendly BCI systems.