Decision making and memory as we grow older
Theodore D. Cosco, PhD (Cantab) CPsychol
Around the world, we’re getting older: the proportion of older adults in the population is steadily rising. Advances in modern medicine and technology have led to widespread increases in longevity. But improvements in the quality of life and the lived experience of growing older have not seen the same level of attention. As we grow older, there are many age-related decreases in various functional capacities, ranging from decreasing manual dexterity and visual acuity to changes in cognitive functioning. Paradoxically, studies of individuals’ perceived happiness over the life course suggest that older adults actually experience disproportionately high levels of life satisfaction and well-being compared to previous time periods in their lives. That’s not to say, though, that there aren’t challenges to be encountered, particularly with respect to aspects of cognition such as decision making and memory.
Cognition exists in a conceptual hierarchy resembling a pyramid, starting with simple tasks and building in complexity.
At the base of the pyramid: attention, which relates to the capacity to direct one’s cognitive efforts toward stimuli.
The second layer: visuospatial and language skills, which include the capacity to orient oneself in the world and to communicate.
The third layer: memory, which includes the ability to store and recall pieces of information.
The top layer: executive functioning, which includes your ability to do complex tasks that integrate aspects of the previous layers of the pyramid, such as making decisions, navigating the public transport system, or preparing a multi-course meal.
It’s important to note that, although growing older is associated with age-related declines in cognitive functioning, not everyone experiences these changes in the same way. Some may experience few to no cognitive changes, while others on the other end of the spectrum may experience debilitating cognitive deficits, such as in those with Alzheimer’s disease.
Interestingly, the development of cognitive skills in early life progresses upward, from the bottom of the pyramid to the top. But these skills are lost in the reverse order in persons who live with dementia. Emerging research provides some insights into the steps we might take toward maintaining high levels of cognitive function over the course of our life.
The concept of “cognitive reserve” refers to the resources we build up over our lives that provide a form of protection against age-related cognitive decline. If you think of this in relation to computers, your brain would be the hardware, and your cognitive reserve the software.
With outdated (or deteriorating) hardware, highly functioning software may be able to compensate for the hardware’s deficits. In the same way, if a person is experiencing neuronal loss (a physical deterioration), greater compensatory mechanisms within their cognitive reserve may be able to offset the brain’s deficits.
If two people are both experiencing challenges finding words in conversation (what is known as “verbal fluency” in the cognition world) they may have different compensatory abilities. Person A, who is a voracious reader and writes for a living, may be better equipped (with a larger vocabulary) to quickly find a synonym if they get stuck on a word than Person B, who has less formal education and reads little. Even if Person A can’t find the exact word they’re looking for, if they can quickly insert a synonym without skipping a beat, their cognitive deficits may be imperceptible to the external observer.
It’s important to know that you can build up your own cognitive reserve by participating in the types of activities that researchers have found to be associated with cognitive reserve. Activities that can help build cognitive reserve include
Even small, incremental changes in lifestyle over time can have long-term impacts, so you don’t have to go from the couch to a marathon to reap the benefits. Starting with small activities and building up over time may help you build the cognitive reserve that puts you in a position to foster healthy aging in your own life.
Mental health and well-being over the life course is an increasingly popular area of research, due in part to their unique trajectories.
Researchers, such as myself, who study how individuals’ happiness changes over time, have noticed that older adults exhibit a unique phenomenon whereby, despite experiencing greater physical, cognitive, and functional impairments, they actually have higher well-being than they did previously in their lives.
This is known by a variety of names, such as the “well-being paradox” or the “resilience paradox.” Exactly why this occurs remains a focus of debate. Research suggests it may be the result of favourable brain changes, that older adults are better at dealing with stress, or that aspirations lower over time to the point where they intersect with reality.
Socialization is part of being human, and it can have positive impacts throughout life. Research has established a link between hearing loss and cognitive decline. One hypothesis for this? People who have hearing-related challenges may be less able to participate in social conversations, resulting in fewer social interactions, which then leads to less cognitive stimulation.
Getting restful sleep, exercising often, and eating a wholesome diet are all important components of healthy cognition as we grow older. Supplements to consider: