Awareness Detection and Communication in Disorders of Consciousness

Change in performance accuracy of BCI use pre- and post- training

The main primary outcome measure is BCI performance (e.g., accuracy in % for repeated binary choice selections using the BCI e.g., movement free control of cursor towards one of two targets using EEG-based BCI or accuracy in discriminating different brain responses associated with imagined movement of different limbs. Multiple cross validation will be performed to assess the significance of the difference between a baseline accuracy (pre cue- where accuracy in the response is expected to be around 50% (chance level)) and the peak accuracy (where the accuracy of discriminating event related brain response peaks following the cue).

Change in ability to use imagined movements to consistently communicate yes-no responses to closed questions over multiple sessions by participant with Prolonged Disorder of Consciousness

Accuracy rate when using the BCI system to provide known responses to statements will be used to build evidence to establish that participants could use the technology as an aided communication method. Examples of questions are given below. Yes Questions: Your name is David. You are 25 years old.

Diagnostic utility of BCI data provided through study completion to clinicians

The performance accuracy of the participant in producing consistent cue- induced imagined movements appropriately in timed paradigms will be assessed across sessions, to determine variability and consistency in performance accuracy. The affects of real-time feedback will be looked at, alongside differences in performance accuracy across question subcategories. Performance accuracy per question subcategory will be assessed to evaluate awareness of self versus awareness of environment and understanding of numbers and letters, and logic. Whether this information is in line with the patient's current diagnosis/CRS-R and WHIM scores will be assessed in order to further understand whether the technology can aid feedback/interpretation on assessment outcomes from consultants?

Changes in Wessex Head Injury Matrix and Coma Recovery Scale Scores due to potential therapeutic benefit of engaging in motor imagery

Is there a benefit to intentionally modulating motor cortex regions in response to a command in a timed paradigm over multiple sessions. In participants with a Prolonged Disorder of Consciousness the scores for The Wessex Head Injury Matrix and Coma-Recovery Scale Revised taken at each session will be looked at to seek out therapeutic benefit. Here therapeutic benefit is defined in terms of changes in state of arousal and awareness of self/environment. Therapeutic benefit may also be assessed via performance given as an accuracy percentage of motor imagery trials successfully completed, and how this changes over time.

Change in performance accuracy as a factor of whether feedback was presented as music or broadband noise,

Is there a significant difference in performance as a function of type of feedback participant was receiving - music clips or broadband noise.

Changes in performance accuracy as a results of time of day of research experimentation

Arousability varies with time of day - is this reflected in BCI use performance or do some patients perform more optimally at a particular time? The aim is to perform 5 sessions in the morning and 5 in the afternoon to look at the affects of time of day.