V-90
Neural Circuits and Systems Neuroscience
Cortico-Cochlear Oscillatory Dynamics in Chronic Tinnitus under the Residual Inhibition Paradigm
Simón San Martín1,2, Constantino Dragicevic1, Cristina de Gatica De Gatica1, Vicente Medel2, Christ Devia1,4,5, Paul Delano1,3,5
1. Universidad de Chile, Departamento de Neurociencia, Facultad de Medicina, Santiago, Chile.
2. Pontificia Universidad Católica de Chile, Departmento de Biomedicina, Facultad de Ciencias Biológicas, Santiago, Chile.
3. (3) Hospital Clínico de la Universidad de Chile, Departamento de Otorrinolaringología, Santiago, Chile.
4. (4) Centro Nacional de Inteligencia Artificial (CENIA), Santiago, Chile.
5. (6) Advanced Center for Electrical and Electronic Engineer (AC3E), Universidad Federico Santa María, Valparaiso, Chile.
Presenting Author:
simonsnm@ug.uchile.cl
Introduction: Chronic tinnitus affects 14% of adults. We used the residual inhibition (RI) paradigm (temporary acoustic suppression) to study its neurophysiological persistence mechanisms, integrating cortical and cochlear levels for treatment response markers. Methods: We conducted a case-control study on 25 chronic tinnitus patients with normal hearing. Subjects were grouped as Responders or Non-Responders based on noise-induced alleviation. We analyzed EEG and DPOAEs during rest, pre- and post-stimulation, comparing PSD and aperiodic (1/f) components. Results: In Responders, delta activity correlated with tinnitus intensity. PSD lacked group differences, indicating a stable trait. However, Non-Responders showed a steeper spectral slope in the right temporal region (T8) and flattened frontal 1/f slope (Fz). Peripherally, Non-Responders had increased Theta and Gamma in DPOAEs, while Responders showed greater modulation in left temporal 1/f knee frequency (T7). Conclusions: RI resistance is driven by cortical aperiodic structure and efferent control, not just oscillatory power. 1/f dynamics and cochlear rhythms are potential biomarkers for tailored tinnitus therapies.
