Cognitive reserve hypothesis and hearing

Abstract

　　There are concepts of the ability to maintain function without clinically developing dementia even if there are pathological changes in the brain. These concepts are called such as cognitive reserve, brain reserve, and brain maintenance. In the cognitive reserve hypothesis, that assumes resistance to brain degeneration, the indicators used as surrogate measures for reserve include brain morphological parameters such as the brain volume, head circumference, and brain weight, which are relatively easy to measure, and also the level of education (years of education and/or quality of education), occupational complexity, IQ and literacy, mental activity, social activity, physical activity, etc. There are various research reports that indicate that hearing loss is disadvantageous in terms of the brain volume atrophy rate, academic achievement rate, continuation of employment, and social interaction. If hearing loss and issues involving hearing loss interfere with the strengthening of the reserve capacity that may delay the onset of dementia, we believe that care of hearing loss will be more important than ever.