Project Details
Projekt
Processing of ultra-precise temporal information by neuronal networks in the auditory brainstem and its degradation after long term hearing loss
Applicant
Professor Dr.-Ing. Werner Hemmert
Subject Area
Cognitive, Systems and Behavioural Neurobiology
Term
from 2012 to 2019
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 218143440
Ultra-precise temporal information processing is essential for the auditory system, as interaural time differences (ITDs) in the range of tens of microseconds provide a dominating cue for sound localization. Moreover, the detection and processing of speech in noisy environments relies also on temporally precise neuronal processing, which deteriorates with accumulating hearing loss.The objective of this project is to assemble the detailed information available within this priority program and create a comprehensive model framework that allows us to retrace how ultrafast temporal information is extracted and re-coded along the auditory pathway. Moreover, we will investigate the deterioration of this system after deafness and how we can restore its function when the auditory nerve is stimulated electrically with a cochlear implant. During this project we will develop and evaluate models of selected neurons in the auditory brainstem and integrate them into our model framework 'cochlea', which already provides state-of-the-art inner ear models. We will include excitatory and inhibitory neurons and synapses that will be based on physiological data as close as possible. In the next step, we will develop a neuronal network model that covers the main processing steps involved in ITD coding. Together with partners within the priority program we will identify processing steps in the ITD pathway, which degenerate or get detuned after hearing loss.While we process these objectives, we will address important scientific questions, how ultraprecise processing of temporal information is realized with relatively (compared to ITD resolution) slow neurons. Specifically, we will analyze which processes contribute to the improvement of synchronization observed in auditory neurons, how inhibition and excitation are fine-tuned. A main focus will also lie on the question, which changes in the ITD pathway lead to the observed degradation of ITD discrimination after hearing loss. These questions are very relevant in an aging society because the incidence of hearing impairment grows rapidly with age. Our model framework will be essential to tackle these questions and trigger new, focused physiological investigations and also psychophysical experiments with hearing impaired listeners and cochlea implant users. Once we have gained a clearer understanding which neuronal mechanisms fail after long term deafness, we can work on countermeasures.We will make our models publicly available such that they can be evaluated, reused and extended by other groups, which will significantly speed-up research. Our models will also facilitate further utilization for technical applications like robot audition, auditory scene analysis, automatic speech recognition, the development of hearing aids and cochlear implants.
DFG Programme
Priority Programmes
