We already know that there is a correlation between hearing loss and decreased brain function. But how does this work exactly?
A study from 2015 focused on neuroplasticity – how the brain reorganizes itself by forming new neuron connections throughout life – and found that in the case of hearing loss, the part of the brain devoted to hearing can actually become reorganized, i.e. reassigned to other functions.
By using EEG recordings the researchers found that when hearing loss occurs areas of the brain devoted to other senses, such as vision or touch, will actually take over the areas of the brain which normally process hearing. It’s a phenomenon called cross-modal cortical reorganization, which is reflective of the brain’s tendency to compensate for the loss of other senses. Essentially, the brain adapts to a loss by rewiring itself. It is a makeover of sorts, but one that can have a serious effect on cognition.
In people with hearing loss, this compensatory system greatly reduces the brain’s ability to process sound, which in turn affects a person’s ability to understand speech. And even with mild hearing loss, the hearing areas of the brain become weaker. What happens next is that the areas of the brain that are necessary for higher level thinking, compensate for the weaker areas. They step in and essentially take over for hearing, leaving them unavailable to do their primary job.
“The hearing areas of the brain shrink in age-related hearing loss,” said Anu Sharma, PhD, a researcher on the University of Colorado study. “Centers of the brain that are typically used for higher-level decision-making are then activated in just hearing sounds. These compensatory changes increase the overall load on the brains of aging adults. Compensatory brain reorganization secondary to hearing loss may also be a factor in explaining recent reports in the literature that show age-related hearing loss is significantly correlated with dementia.”
Even in the early stages of hearing loss, the brain begins to reorganize. Knowing this, the solution could be as simple as early hearing loss screening programs for adults.
Read the whole article at Healthy Hearing