Aging Brain and Hearing: A Mini-Review

Abstract

Brain reserve is a topic of great interest to researchers in aging medicine field. Some individuals retain well-preserved cognitive function until they fulfill their lives despite significant brain pathology. One concept that explains this paradox is the reserve hypothesis, including brain reserve that assumes a virtual ability to mitigate the effects of neuropathological changes and reduce the effects on clinical symptoms flexibly and efficiently by making complete use of the cognitive and compensatory processes. One of the surrogate measures of reserve capacity is brain volume. Evidence that dementia and hearing loss are interrelated has been steadily accumulating, and age-related hearing loss is one of the most promising modifiable risk factors of dementia. Research focused on the imaging analysis of the aged brain relative to auditory function has been gradually increasing. Several morphological studies have been conducted to understand the relationship between hearing loss and brain volume. In this mini review, we provide a brief overview of the concept of brain reserve, followed by a small review of studies addressing brain morphology and hearing loss/hearing compensation, including the findings obtained from our previous study that hearing loss after middle age could affect hippocampal and primary auditory cortex atrophy.

Asymmetries and hemispheric interaction in the auditory system of elderly people

“…Future studies need to decipher further the effects of changes in functional and anatomical hemispheric asymmetries and reduced hemispheric interaction with age, age-related hearing loss and declining cognitive abilities, all of which influence each other in various ways (Humes et al, 2012 ; Rönnberg et al, 2013 ; Cardin, 2016 ; Ebaid and Crewther, 2020 ; Uchida et al, 2021 ; Lentz et al, 2022 ). Therefore, all studies should be conducted with young control participants who are comparable in terms of their peripheral hearing and cognitive abilities.…”

The Development of Speaking and Singing in Infants May Play a Role in Genomics and Dementia in Humans

“…A novel idea of the effects of hearing aids on neurodegenerative diseases was further explored [ 92 , 93 ]. Griffiths et al [ 92 ] grouped them into four potential mechanisms based on the typical cochlea, brainstem, and forebrain pathology.…”

“…Griffiths et al [ 92 ] grouped them into four potential mechanisms based on the typical cochlea, brainstem, and forebrain pathology. Hearing aids will help auditory hearing, but currently, there is not sufficient evidence to recommend the use of hearing aids to reduce cognitive decline [ 93 ]. The structural and functional features of the auditory brain could play a reciprocal interplay between peripheral and central hearing dysfunction [ 94 ], which seems to be particularly affected by the ‘tau’ proteins [ 95 ].…”

The cognitive hearing science perspective on perceiving, understanding, and remembering language: The ELU model

“…However, that is the overall picture and the more specific underlying mechanism as to why hearing loss is a risk factor for dementia is still argued to be unclear ( Wayne and Johnsrude, 2015 ; Hewitt, 2017 ). Other independent analyses from the UK Biobank resource suggest that subclinical small variations in hearing acuity may still be associated with loss of gray matter volumes in the brain, especially in areas related to cognition and hearing ( Rudner et al, 2019 ; however, see further about brain atrophy and cognitive reserve Uchida et al, 2021 ).…”