A Brain-computer Interface Based on Three-dimensional Stereo Stimuli for Assisting Clinical Object Recognition Assessment in Patients with Disorders of Consciousness.

The Coma Recovery Scale-Revised (CRS-R) behavioural scale is commonly used for the clinical evaluation of patients with disorders of consciousness (DOC). However, since DOC patients generally cannot supply stable and efficient behavioural responses to external stimulation, evaluation results based on behavioural scales are not sufficiently accurate. In this study, we proposed a novel brain-computer interface (BCI) based on three-dimensional (3D) stereo audiovisual stimuli to supplement object recognition evaluation in the CRS-R. During the experiment, subjects needed to follow the instructions and focus on the target object on the screen, whereas EEG data were recorded and analyzed in real time to determine the object of focus, and the detection result was output as feedback. Thirteen DOC patients participated in the object recognition assessments using the 3D audiovisual BCI and CRS-R. None of the patients showed object recognition function in the CRSR assessment before the BCI experiment. However, six of these DOC patients achieved accuracies that were significantly higher than the chance level in the BCI-based assessment, indicating the successful detection of object recognition function in these six patients using our 3D audiovisual BCI system. These results suggest that the BCI method may provide a more sensitive object recognition evaluation compared with CRS-R and may be used to assist clinical CRS-R for DOC patients.