Brain Health Cognitive Aging & Dementia

Cognitive Aging & Dementia

Cognition is a term that describes thinking processes, memory and mental abilities. Cognition dynamically changes across the entire lifetime. For healthy older adults, it is normal to experience some cognitive decline that may be noticeable but does not interfere with daily life.

Declarative Memory

describes the ability to recall people, places and events. This is the most common type of memory complaint; for example, when we forget a name or an appointment. This type of memory failure is common for people of all ages and becomes more frequent after middle age. A healthy older adult may become more forgetful but will later remember the information. The ability to form new memories declines with age but the ability to recall information from long before, such as from childhood, is relatively preserved.

Working Memory and Executive Function

is a broad category of function describing abilities to keep information in mind, manipulate it, and apply it to make decisions. For example, doing a math problem in your mind uses working memory. Executive functions include the ability to control attention and stop actions. For example, sitting at a stoplight and waiting for the light to turn green. These functions decline in normal aging and result in more errors, difficulty maintaining long lists of information in mind, and greater susceptibility to distraction.

Processing Speed

describes how quickly we can think and respond to information in the environment. Processing speed generally slows in older age and partially contributes to declines in declarative memory, working memory and executive function. Slowed processing speed may be more noticeable when doing difficult tasks or needing to switch between multiple tasks; for example, cooking a meal that requires many steps, different temperatures and timing.

Crystallized Ability

describes knowledge and skills that, once learned, are resistant to change. For example, knowledge of vocabulary and reading ability continues to improve until middle age and do not decline in normal aging. Procedural skills are habits and motor behaviors—like riding a bike, playing the piano or signing your name—that are resilient in normal aging. Wisdom and world knowledge develop across our lifetime and are maintained through our latest years.

1 of 4

What is Dementia

Dementia is an umbrella term that describes meaningful cognitive decline that interferes with everyday activities. Dementia is typically determined following cognitive, or neuropsychological, assessment as part of a clinical disease diagnosis, such as Alzheimer’s disease. Dementia can present with poor declarative memory, working memory or executive function. The type and severity of cognitive impairment directly relates to the parts of the brain affected by the specific disease.

Dementia is different from normal aging. Some cognitive decline occurs in normal aging and not all forgetful moments are a sign of dementia.

Early Signs of Dementia

One of the challenges in identifying dementia is that the clinical condition develops over time and cannot be distinguished from normal aging until impairments become severe enough to interfere with daily activities. A good way to monitor your cognitive health is to have regular appointments with your primary care physician and talk about any changes in your thinking and memory ability.

Early signs of dementia include:

More forgetfulness than normal
Difficulty making plans or solving problems
Recurring disorientation or confusion with dates and places
Trouble completing familiar tasks

New problems with words when speaking or writing
Frequently misplacing things and losing the ability to retrace steps
Changes in mood and personality, or withdrawal from social activities

If you are concerned that you or someone you know may have dementia, consult a physician and ask for a cognitive assessment. Your physician may ask about your recent sleep quality, diet, alcohol use, and mood, and will review possible side effects of medications. These factors can cause temporary cognitive impairment and a physician will work to rule out these as possible causes that are not due to dementia.