Measurement of the Hippocampal Theta Rhythm From the Outer Ear Canal

New technologies are needed to help diagnose anxiety disorders. EVestG has facilitated the identification of numerous possible biomarkers of several psychiatric disorders. Some EVestG features seem to be caused by differences in low-frequency modulation that is consistent (both in frequency and behaviour) with the hippocampal rhythm (theta), which is known to play a role in anxiety. Critically, there is ample support in the literature for an anatomical and functional basis for the modulation of vestibular signals via theta. If anxiety could be measured continuously, perhaps throughout a patient's day, or throughout a task, it might be able to confirm an anxiety disorder. However, current techniques for measuring theta are highly invasive, performed rarely, and only in epilepsy patients. EVestG technology, however, is non-invasive, and could potentially record anxiety levels in any subject for extended periods of time. The proposed study will attempt to identify hippocampal theta in vestibular signals in healthy participants through a double-blind administration of two different drugs that are dissimilar both pharmacologically and in acute clinical effects but which are known to reduce the theta rhythm.