Age-Related Cognitive Decline....What's Normal, What's Not?
As we age, our brain shrinks, therefore the areas that control everything from thinking, speaking, processing information, problem solving, and memory will likely be impacted at one point or another. Aging is one of the biggest risk factors for cognitive impairment. This is important since the number of Americans over 65 years old is projected to nearly double over the next forty years, increasing from 52 million in 2018 to approximately 96 million in 2060. Therefore, it will become increasingly important for us all to understand the cognitive changes that accompany aging. This includes both normal age-related cognitive decline as well as the pathologic neurodegenerative process (such as an Alzheimer’s disease).
Dementia and mild cognitive impairment (MCI) are both common for many individuals as they age, however, even individuals who do not experience these conditions may experience subtle cognitive changes associated with aging. These age-related cognitive changes are important to understand because:
A) They can begin to impact an older adult’s day to day function.
B) They can help us distinguish what is considered normal or typical versus something that is considered to be degenerative disease or condition.
Cognitive change as a normal process of aging has been well documented in the scientific literature. Some cognitive abilities, such as vocabulary, are considered to be resilient to brain aging and for some individuals it may even improve with age. Other abilities, such as verbal reasoning, memory, and processing speed tend to gradually decline over time.
Age-related cognitive changes typically start to occur when individuals are in middle age with respect to memory (declines in other domains occur at varying ages). Forgetfulness can be a normal part of aging but it is the frequency and severity of forgetfulness that tends to distinguish it from age-related to some other cause (e.g., organic changes, psychological distress, etc.). As people age, it is well known and observed that the body and the brain change. We start to notice that oftentimes it takes longer to perform a new task, it takes longer to learn new things, and it is more difficult to multi-task or shift back and forth between tasks.
Areas of Cognition:
Intelligence: “Crystalized” intelligence (i.e., knowledge or experiences that we have accumulated over time) remains stable with age. On the other hand, “fluid” intelligence (i.e., the abilities not based on past experience or education) tend to decline.
Attention: Simple or focused attention such as the ability to attend to a television program tends to be preserved in older age. On the other hand, complex and divided attention can become more difficult to perform as we age. For example, this can occur when trying to pay attention to the television and simultaneously talk on the telephone.
Speed of Processing: As we age, the speed that we are able to perform cognitive and motor processes begins to be negatively impacted. Essentially, this means that you can still perform those types of tasks or activities but it is going to take you longer to mentally process that information than in the past.
Language: Verbal abilities such as vocabulary and word knowledge are preserved as we age. However, more commonly the changes we notice have to do with word retrieval or the process of getting words out. It takes longer and is more difficult to find the words one wants when engaged in conversation or trying to recall names of people and objects. The information is not necessarily lost but it is more difficult to retrieve. You begin to have more moments in which you mentally know the word but it feels like it is stuck on the tip-of-your-tongue.
Memory: Long-term or remote memory/recall of past events that have been stored over many years remains relatively preserved in old age. However, we are more likely to experience difficulties with recent memory or the formation of new memories as we age.
Reasoning and Problem Solving: The ways we approaching solutions for problems tends to be maintained as we age. However, it may take longer or extra time to figure out the best approach. Or it may become more difficult for you to explain the reasoning or explain the steps to take.
What Factors Can Impact Cognitive Abilities As We Age?
Our cognitive abilities can be affected by many different factors. The more factors that we are experiencing can further exacerbate the efficiency with which older adults process information. These include:
A) Medications which may produce side effects such as drowsiness and mental dullness;
B) Sensory changes which can interfere with the processing of information (e.g., loss of hearing which can affect whether or not someone’s name is heard when introduced);
C) Health related changes such as arthritis and chronic pain which can affect cognitive areas such as concentration and processing speed; and
D) Changes in mood such as depression and anxiety which can alter one’s motivation to learn new information and to apply active strategies.
Compensating And/Or Slowing Down Age-Related Changes
We may not be able to immediately stop all cognitive decline but we know that certain interventions can help sharpen cognitive processes. These include:
Reducing Stress: Researchers have found that chronic high stress levels impair learning and memory in both animals and humans. Strategies to reduce stress such as exercise and mindfulness deep breathing may be beneficial.
Maintaining Good Health: Regular visits to the doctor are vital to make sure that medical conditions which can themselves impair thinking are under good control and well-managed. In addition, possible interactions among medications should be evaluated by letting your physician know all of the medications you are taking, even if not prescribed by that particular doctor.
Maintaining a Healthy Diet: A diet rich in healthy fats (such as olive oil and fish) as well as fruits and vegetables (such as blueberries, strawberries, and broccoli) may be neuroprotective. Limiting and reducing processed foods, unhealthy fats, and sugary foods can also be helpful.
Keeping Mentally Stimulated: Studies have found that keeping people engaged in challenging cognitive tasks can protect against age-related declines in thinking and the risk of developing Alzheimer’s disease. It is important to keep oneself stimulated through activities such as playing bridge, reading, puzzles, sudoku, and attending life-long adult education courses.
Using Active Strategies: There is evidence that some of the difficulties in storing new memories are due to the fact that older persons do not spontaneously use strategies to encode this information. When they do, age differences are weakened. In addition, older adults demonstrate good recognition of new information when they are helped with cues to jog their memory. Strategies that can be helpful to facilitate memory include following a routine (e.g., always putting one’s keys in the same place), using external techniques (e.g., a calendar, a pill box), and taking more time to actively process new information (e.g., when introduced to someone, pay extra attention and try to come up with an association to recall that person’s name)
By definition, normal age-related cognitive change does not impair a person’s ability to perform daily activities. If an older adult develops functional impairments, even with complicated tasks such as managing finances or medications, it is sensible to pursue a workup for dementia by a neurologist and neuropsychologist especially if there is no other obvious explanation for these difficulties, such as a reaction to a medication, a new medical illness, or a vision or hearing problem.