Abnormally enhanced temporal correlations of alpha oscillations across multiple timescales in tinnitus patients.

Tinnitus is a phantom auditory perception that occurs without an external stimulus. Increasing evidence suggests that it is associated with abnormal predictive coding, in which overly strong priors may give rise to hallucinatory perception, as proposed by the "strong priors" hypothesis. Neurodynamic analysis, by characterizing the temporal evolution of brain activity, can further test the "strong priors" hypothesis in tinnitus, specifically whether tinnitus patients' brain activity is more influenced by past activity. However, the neurodynamic characteristics of tinnitus remain poorly understood. Therefore, we examined long-range and short-range temporal correlations in resting-state Electroencephalography (EEG) signals from tinnitus patients and healthy controls. We applied detrended fluctuation analysis, lifetimes, and waiting times to assess temporal correlations across multiple time scales. Our results showed that tinnitus patients exhibited stronger temporal correlations in the alpha frequency band, accompanied by heightened long-range dependencies in higher frequency bands. These findings reveal an abnormally enhanced temporal structure across multiple timescales and frequency bands in tinnitus, potentially reflecting an excessive influence of global context on intrinsic information processing and providing support for the "strong priors" hypothesis.