Hearing and Cognitive Aging
- Margaret Kathleen Pichora-FullerMargaret Kathleen Pichora-FullerPsychology, University of Toronto
Age-related hearing loss is heterogeneous. Multiple causes can damage the auditory system from periphery to cortex. There can be changes in thresholds for detecting sound and/or in the perception of supra-threshold sounds. Influenced by trends in neuroscience and gerontology, research has shifted from a relatively narrow modality-specific focus to a broader interest in how auditory aging interacts with other domains of aging. The importance of the connection between sensory and cognitive aging was reported based on findings from the Berlin Aging Study in the mid-1990s. Of the age-related sensory and motor declines that become more prevalent with age, hearing loss is the most common, and it is the most promising as an early marker for risk of cognitive decline and as a potentially modifiable mid-life risk factor for dementia. Hearing loss affects more than half of the population by 70 years of age and about 80% of people over 80 years of age. It is more prevalent in people with dementia than in peers with normal cognition. People with hearing loss can be up to five times more likely to develop dementia compared to those with normal hearing. Evidence from cross-sectional studies has confirmed significant correlations between hearing loss and cognitive decline in older adults. Longitudinal studies have demonstrated that hearing loss is associated with incident cognitive decline and dementia. Various biological, psychological, and social mechanisms have been hypothesized to account for these associations, but the causes remain unproven. Nevertheless, it is widely believed that there is a meaningful interface among sensory, motor, and cognitive dysfunctions in aging, with implications for issues spanning brain plasticity to quality of life. Experimental research investigating sensory-motor-cognitive interactions provides insights into how age-related declines in these domains may be exacerbated or compensated. Ongoing research on auditory aging and how it interfaces with cognitive aging is expected to increase knowledge of the neuroscience of aging, provide insights into how to optimize the everyday functioning of older adults, and inspire innovations in clinical practice and social policy.