The Electrophysiological Explorations in Tinnitus Over the Decades Using EEG and MEG

Ever since animal studies confirmed a more central origin of tinnitus, there has been a constant search for an objective marker of tinnitus with a thirst to unravel its mechanism of action. Researchers have used sound-evoked and resting state electrophysiological measures such as auditory brainstem responses, auditory steady-state responses, middle and long latency responses and resting state brain activity recorded using both an electroencephalogram and magnetic encephalogram to understand the neural correlates of tinnitus. What started as an exploration of changes in brain activity between tinnitus and non-tinnitus participants has evolved into understanding how networks of brain regions encode different behavioural characteristics of tinnitus and segueing into mobilising big data to build models to predict the same characteristics based on neural data. In the current chapter, we take a deep dive into various electrophysiological studies that have tried to achieve this through the ages and summarise what we know about tinnitus and its neural correlates using EEG and MEG and where we think the field is headed.