Physiological regulation of chronic tinnitus: A new methodological approach

Abstract

Decrease of auditory alpha-rhythm might lead to tinnitus which it calls a rehabilitation strategy using training to increase auditory alpha in chronic tinnitus patients. A novel auditory alpha monitoring method was devised to circumvent the inverse problem of standard EEG source localization methods. To prevent projection of alpha from somatosensory and occipital cortex, alpha-blockade of these two regions using tactile and visual stimulations is integrated in an EEG neurofeedback set-up. The monitoring online source method’s results showed rigorous tracking of auditory alpha activity purely from the sensor-level while the up-regulation of auditory alpha activity was very difficult for tinnitus patients. Therefore, only contingent feedback was applied instead of using a control condition or control group. Although the neurofeedback training exerted a positive effect on the tinnitus symptoms, this effect was not a consequence of neurophysiological changes, but it was probably the effect of positive expectancy and the reduction of cognitive dissonance related to the attribution of concentration and effort. Different reasons could be responsible for this lack of covariation between neurophysiology and behavior like short training time for up-regulation of alpha activity or permanent neuronal reorganization. However, the developed on-line neurofeedback of localized alpha allows systematic replication and variation of the determining variables of neurofeedback training in tinnitus in future larger clinical trials.