Abstract
BackgroundCurrently, it is challenging to detect the awareness of patients who suffer disorders of consciousness (DOC). Brain-computer interfaces (BCIs), which do not depend on the behavioral response of patients, may serve for detecting the awareness in patients with DOC. However, we must develop effective BCIs for these patients because their ability to use BCIs does not as good as healthy users.MethodsBecause patients with DOC generally do not exhibit eye movements, a gaze-independent audiovisual BCI is put forward in the study where semantically congruent and incongruent audiovisual number stimuli were sequentially presented to evoke event-related potentials (ERPs). Subjects were required to pay attention to congruent audiovisual stimuli (target) and ignore the incongruent audiovisual stimuli (non-target). The BCI system was evaluated by analyzing online and offline data from 10 healthy subjects followed by being applied to online awareness detection in 8 patients with DOC.ResultsAccording to the results on healthy subjects, the audiovisual BCI system outperformed the corresponding auditory-only and visual-only systems. Multiple ERP components, including the P300, N400 and late positive complex (LPC), were observed using the audiovisual system, strengthening different brain responses to target stimuli and non-target stimuli. The results revealed the abilities of three of eight patients to follow commands and recognize numbers.ConclusionsThis gaze-independent audiovisual BCI system represents a useful auxiliary bedside tool to detect the awareness of patients with DOC.
Highlights
It is challenging to detect the awareness of patients who suffer disorders of consciousness (DOC)
In summary, a gaze-independent audiovisual brain-computer interface (BCI) was developed for detecting the awareness of patients with DOC in this study
Multiple Event-related potential (ERP) components, including the P300, N400 and late positive complex (LPC), were enhanced by the semantically congruent and incongruent audiovisual stimuli, which might be useful for improving audiovisual BCI performance
Summary
It is challenging to detect the awareness of patients who suffer disorders of consciousness (DOC). BCIs can potentially detect the awareness of patients with disorders of consciousness (DOC), such as unresponsive wakefulness syndrome (UWS, formerly known as the vegetative state [6]) and minimally conscious state (MCS). Keystones in diagnosis lies in recovering the voluntary response, such as the ability to follow commands and functional use two different objects, which indicates emergence from the UWS and the MCS, respectively [7]. Lule et al [13] proposed an auditory oddball EEG-based BCI paradigm based on data from 16 healthy subjects, 3 patients with UWS, 13 patients with MCS, and 2 patients with locked-in syndrome (LIS). The use of BCI for detecting awareness of patients with DOC remains in primary stage These patients exhibit a generally weak BCI performance as they have a much lower cognitive ability than healthy individuals. Many efforts should be taken for developing novel BCIs to enhance the performance of awareness detection
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
