A Novel Audiovisual Brain-Computer Interface and Its Application in Awareness Detection

Area of Science:

• Neuroscience
• Biomedical Engineering
• Rehabilitation Medicine

Background:

• Detecting awareness in patients with disorders of consciousness (DOC) is challenging, often relying on behavioral scales.
• Brain-computer interfaces (BCIs) offer an alternative but face challenges with reduced patient capability.

Purpose of the Study:

• To develop and evaluate a novel audiovisual brain-computer interface (BCI) for detecting awareness in patients with DOC.
• To assess the efficacy of temporally, spatially, and semantically congruent audiovisual stimuli.

Main Methods:

• Developed a BCI system using congruent audiovisual stimuli (visual and spoken numbers).
• Tested the system on 10 healthy subjects, comparing audiovisual, auditory-only, and visual-only conditions.
• Applied event-related potential (ERP) analysis to examine neural responses.
• Validated the system on 7 patients with DOC.

Main Results:

• The audiovisual BCI system significantly outperformed auditory-only and visual-only systems in healthy subjects.
• Evidence of audiovisual integration effects was observed, enhancing target stimulus discrimination.
• Five out of seven DOC patients demonstrated command following and number recognition using the BCI.

Conclusions:

• The proposed audiovisual BCI system demonstrates superior performance in detecting awareness compared to unimodal BCIs.
• Audiovisual integration enhances the brain's discriminability of stimuli, improving BCI accuracy.
• This system holds potential as a supportive bedside tool for assessing awareness in patients with DOC.