Abstract
Chronic subjective tinnitus is an audible sound that lacks an external source. A notable number of neuroscientific studies have been conducted applying magnetoencephalography and electroencephalography (MEEG) in resting state paradigms to elucidate neural correlates of tinnitus. In these studies, recordings were usually performed without particular instructions to the participant. Thus, it remains unclear whether resulting MEEG measures may have been affected by attention on the actual tinnitus percept. In order to investigate this potential source of variance in tinnitus MEEG resting state results, we investigated the difference between non-instructed resting state (RS) and active listening to tinnitus (AL) using questionnaires as well as EEG power analysis (n = 45). Questionnaire scores for the two conditions resulted in significant increases in tinnitus distress and presence during AL. Beyond that, no differences in EEG band power were found between the conditions both on the sensor and source levels. Results point to an expected increased tinnitus presence and distress in the AL condition on the behavioral level. These behavioral changes are not reflected in changes in EEG oscillatory power, which is especially surprising when looking at the alpha band related to general external and internal attentional processes. Furthermore, no changes in other frequency bands (delta, theta, beta, gamma) attributed to aspects of tinnitus distress, loudness, and maintenance were observed. In conclusion, the absence of EEG power changes between conditions may be in support of a chronic and invariant state of altered MEEG signatures in tinnitus. Further studies are needed to better elucidate MEEG resting state paradigms in tinnitus.
Neff, Patrick