CBBM Lecture canceled: Does aging ...

by Dr. Rüdiger Land, Institut für Audioneurotechnologie, Medizinische Hochschule Hannover

Canceled: Tuesday, April 4th, 2023 from 16:00 to 17:00 hours in CBBM Building, Ground Floor, Seminar Room Levi-Montalcini.

Host: Prof. Jonas Obleser, Institut für Psychologie 1

Abstract: The potential impact of central auditory aging on hearing ability in the elderly - independent of peripheral hearing loss - is an important issue in aging societies. Self-reported hearing problems of elderly adults with ‘clinically normal’ peripheral hearing are often explained by age-related changes in the central auditory pathway. However, inaccessible to psychophysical methods, the underlying age-related central neural changes remain poorly differentiated. In order to cause perception deficits, it needs to be shown that central auditory aging effectively degrades neural sound representations at some point along the auditory pathway. We studied, how small age-related changes of simple parameters such as gap detection thresholds and ABR wave latencies affect complex sound representations along the central auditory pathway. Specifically, we measured the effect of age-related changes in the auditory brainstem on the stability of complex spatiotemporal multiunit ‚speech-like’ sound representations in the auditory midbrain of aged normal-hearing CBA mice. We found that, although brainstem conduction speed slowed down with age, the change was limited to the sub-millisecond range and only minimally affected temporal processing (i.e. gaps-in-noise sensitivity) in the midbrain of old mice. Importantly, besides a small delay, multiunit complex temporal sound representations in the auditory midbrain did not differ between young and old mice. This indicates that although small age-related effects on simple sound parameters in the brainstem may occur they do not effectively degrade complex neural sound representations at the level of the auditory midbrain. The result challenges the widespread belief of ‘pure’ central auditory processing deficits as an automatic consequence of aging up the level of the auditory midbrain. In addition, the finding emphasizes the role of undetected ‘hidden’ peripheral damage and accumulating effects toward higher cortical auditory-cognitive processing to explain perception deficits in ‘normal’ hearing elderly