Evaluation of Different Types of Stimuli in an Event-Related Potential-Based Brain-Computer Interface Speller under...

Area of Science:

• Neuroscience
• Biomedical Engineering
• Human-Computer Interaction

Background:

• Rapid serial visual presentation (RSVP) is a gaze-independent paradigm for visual brain-computer interfaces (BCIs).
• Gaze-independent BCIs are crucial for users with limited eye movement control.
• Less research exists on optimal visual stimuli for gaze-independent BCIs compared to gaze-dependent ones.

Purpose of the Study:

• To investigate the influence of stimulus color on event-related potential (ERP)-based BCI performance under RSVP.
• To compare the effectiveness of grey letters versus colored famous faces as visual stimuli.

Main Methods:

• Fifteen participants completed an RSVP-based ERP-BCI task.
• Four conditions were tested: grey letters (GL), red famous faces with letters (RFF), green famous faces with letters (GFF), and blue famous faces with letters (BFF).
• Performance accuracy and user comfort ratings were recorded for each condition.

Main Results:

• Significant accuracy differences were found only between the grey letters (GL) and green famous faces with letters (GFF) conditions.
• Grey letters (GL) yielded higher user comfort ratings than face-related stimuli.
• Unlike gaze-dependent studies, colored faces did not consistently outperform grey letters.

Conclusions:

• Stimulus type significantly affects both performance and user comfort in gaze-independent ERP-BCIs.
• Grey letters may be a more suitable stimulus for RSVP-based gaze-independent BCIs, offering better performance and comfort.
• Future ERP-BCI designs should carefully consider stimulus selection for optimal user experience.