Naturalistic paradigms for neuroimaging and bedside measures of conscious awareness
Abstract
Complex, naturalistic stimuli can test for covert awareness in behaviourally non-responsive patients. For patients with poor visual function, this thesis aimed to identify an auditory-only stimulus that could evaluate executive function. Also, it assessed if Galvanic Skin Response could be a suitable bedside testing method. Healthy individuals listened to 4 auditory stimuli in the fMRI scanner. During Galvanic Skin Response recording, an independent group of controls listened to an audio narrative and watched a movie. Behaviourally non-responsive patients were also tested during movie viewing. Using fMRI, an audio narrative was identified that produced widespread brain synchronization between healthy participants, critically in the frontoparietal network. Healthy controls showed highly similar GSR to a suspenseful movie. A locked-in syndrome patient had a similar GSR to controls during movie viewing. The audio narrative can be used for future patient testing, and GSR can be used to test for consciousness at the bedside.