Older individuals commonly experience some degree of cognitive health decline which can be as simple as intermittent memory loss.  In more severe cases, this neurodegeneration can manifest as Alzheimer's Disease, or other forms of dementia.

The most important changes in cognitive ability associated with normal aging are declines in performance on cognitive tasks that require one to quickly process information in order to make decisions.  This includes information processing speed, a properly functioning memory, and executive cognitive function..

Executive function, in this context, refers to complex cognitive skills, upon which simpler brain activities depend.  Executive cognitive activities are primarily associated with the frontal lobe and involve how we organize thoughts and information, and how we adjust and adapt to environmental changes.  These activities also include our ability to multi-task, our verbal coherency, how we plan activities, and how we store, retrieve, and integrate information.

Functional and structural changes in the brain correlate with these age-associated cognitive changes, including alterations in neuronal structure, loss of synapses, and compromised neuronal networks.  Age-associated diseases accelerate the rate of cognitive decline, neuronal loss, and neuronal dysfunction.  Many people develop cognitive impairments severe enough to impact their ability to function in simple, everyday situations.

A healthy brain is critical for older people to function independently.  It can impact whether someone can communicate effectively, drive safely, manage finances, and take medications correctly.  With the rapidly increasing number of adults over 65, the overall incidence of age-associated neurodegenerative dementia, like Alzheimer's Disease, is increasing.  The number of people diagnosed with Alzheimer's Disease is expected to increase to 13.8 million people in 2050.