An optimized facial stimuli paradigm for hybrid SSVEP+P300 brain computer interface

Area of Science:

• Neuroscience
• Biomedical Engineering
• Human-Computer Interaction

Background:

• Hybrid brain-computer interfaces (BCI) merge event-related potentials (P300) and steady-state visual evoked potentials (SSVEP) to improve performance.
• Integrating human facial stimuli aims to enhance cortical responses in hybrid SSVEP+P300 BCI systems.
• Investigating the feasibility of eliciting distinct potentials using face and non-face stimuli is crucial for hybrid BCI development.

Purpose of the Study:

• To enhance a four-choice command system using a hybrid BCI merging P300 and SSVEP.
• To compare the effectiveness of facial stimuli against non-face stimuli in evoking cortical responses for hybrid BCI.
• To evaluate novel paradigms for simultaneous P300 and SSVEP elicitation.

Main Methods:

• Developed and tested four paradigms: non-face, neutral face, emotional face, and a combined emotional face with flickering stimulus.
• Utilized an LCD screen (60 Hz refresh rate) in a darkened room for stimulus presentation.
• Collected data from ten healthy volunteers (seven male, aged 22-28 years).

Main Results:

• The face-emotional and flicker paradigm demonstrated superior performance compared to other tested paradigms.
• This paradigm achieved the highest information transfer rate (ITR) and user comfort.
• Facial expression changes and flickering stimuli proved effective in eliciting stronger cortical potentials.

Conclusions:

• The face-emotional and flicker paradigm is the most effective for hybrid SSVEP+P300 BCI systems.
• This approach significantly enhances system accuracy, information transfer rate, and user comfort.
• Further research into stimulus parameters is needed to optimize simultaneous multi-potential BCI.