Tinnitus is the perception of sound in the absence of a corresponding source. It affects around 6% of the New Zealand population, and can have considerable debilitating effects on mental health and quality of life. There are some support options available, such as using a tinnitus masker to offer some relief from the intrusiveness of the tinnitus, or undergoing cognitive behavioural therapy to help the sufferer regulate their emotions concerning their tinnitus. However, a limitation is that these options address the symptoms but don't offer a cure for tinnitus.
Unfortunately, no cure is available yet. However, over recent years there has been much progress in understanding the abnormal brain activity associated with tinnitus. It is thought that a complete understanding will reveal the path towards a cure.
With this in mind, the present research aims to study the brain activity in a group of tinnitus sufferers who have the rare ability to turn their tinnitus on and off. As a side-effect of prior brain surgery, these individuals have a phenomenon called ‘gaze-evoked tinnitus’, which is characterised by tinnitus sounds coming on and off according to the position of the eyes. For example, looking ahead may give no tinnitus, but looking to one side might cause a sound like ringing to be heard. This phenomenon offers us a unique opportunity to compare the brain activity in the same person at different times - either with and without their tinnitus - simply by asking people to look in certain directions. We suggest that this comparison will enable us to pinpoint the tinnitus-related brain activity (both type, and location) in a way that is not open to uncertainty or ambiguity as can be the case when comparing the brain activity between, for example different people (some with tinnitus and some without). This is because when comparing across different people or groups in this way, there can be natural variation that is present anyway. The present study will eliminate this variation. We plan to survey and then invite a group of people with gaze-evoked tinnitus to our lab in the University of Canterbury, to study their brain activity using non-invasive techniques.