Older adults are more easily distracted, research reports

RIVERSIDE, California — When engaged in a physical task that requires effort, such as driving a car or carrying grocery bags, older adults are more likely than younger adults to be distracted by items irrelevant to the task at hand, University of California , Riverside , study report.

The study assessed the interaction between physical activity and short-term memory performance when impairment was present or absent in younger and older adults.

“Action and cognition, which frequently interact in everyday life, are sensitive to the effects of aging,” said graduate student Lilian Azer, first author of the research paper published in the journal. Psychology and Aging. “Our study found that compared with younger adults, older adults tended to ignore distractions in their environment when simultaneously engaging in both cognitive and strenuous physical tasks. Ignoring items irrelevant to the task decreased with age and the decline was greater when performing physical tasks simultaneously — a frequent occurrence in everyday life.

According to Azer, age-related differences can be amplified in situations where task demands are higher, such as increasing physical activity or having more distractions.

This study examines what effect simple physical actions have on working memory and inhibition control. Working memory, sometimes referred to as short-term memory, is a core cognitive process that retains information while engaging in ongoing mental activity. Inhibitory control is the ability to ignore distracting information that is not relevant to the task while focusing on task-relevant information.

Researchers recruited 19 older adults, ages 65-86 from a local community in Riverside, California, for a two-year study. Thirty-one young adults, all aged 18-28 years, were recruited from the UC Riverside undergraduate psychology program and awarded course credit.

All participants were asked to hold a hand dynamometer, a type of gripping device, at 5% or 30% of their strength while they performed a short-term memory task. Centrally located visual gauges provide real-time feedback on applied gripping force; nearby, the memory array consists of small blue and red orientation bars. The participant grip is the type used when carrying grocery bags, climbing stairs, or while driving.

Participants should focus on the red cross. Blue bars act as a distraction – mimicking everyday distractions like bright billboards, car horns, or unrelated conversations. During the uninterrupted exercise, they were shown three red bars for a moment and then asked to remember the orientation of the bars. With a distraction, they were also shown five blue bars and instructed to remember only the orientation of the red bars.

“We found that under high physical effort, older adults tended to ignore distracting information and focus on task-relevant information,” said Azer. “Our results suggest that older adults may have a high rate of impairment.”

Starting in 2030, older Americans will make up 21% of the population, up from 15% in 2018. By 2060, nearly 25% of Americans will be aged 65 and over.

Weiwei Zhang, who led the research and in whose laboratory Azer worked, stressed the importance of understanding age-related declines in physical and mental functioning along with their interactions. He explains that as we age, we may experience decreased muscle mass and strength, and declines in key cognitive processes — poorer short-term memory, slower information processing speed, and increased distraction — as a function of normal cognitive aging.

“It is important to understand that as we age, we may be more susceptible to distraction and this can be strengthened during simultaneous physical acts,” said Zhang, a psychology professor and member of UCR’s Aging Initiative. “Understanding how cognitive and physical actions interact can help us become more aware of how distracting information in our environment can impair our working memory.”

The decline in our ability to ignore distractions as we age is a result of normal cognitive aging. The prefrontal cortex, the part of the cerebral cortex involved in consolidation of remote memories, plays a role, and is usually involved in working memory and processes involving inhibitory control.

Azer explains that effortful mental or physical activity is essential to our daily functioning. For example, when driving, we tend to grip the steering wheel with about 30% of our maximal physical strength. When we carry heavy bags of groceries, we tend to use about 20% of our maximum physical strength.

“When we engage in these physical activities, very often we are simultaneously engaging in cognitive tasks in which distractions – billboards or radio car sales ads – may be present,” says Azer. “Inhibitory control may suffer during these concurrent tasks, making it more difficult, especially for older adults, to ignore the distractor and focus on task-relevant information. Because we rarely perform physical or cognitive tasks in complete isolation, it’s important to minimize distractions. If this is not possible, we need to be aware that strenuous physical tasks can impair our ability to perform working memory tasks and successfully ignore distracting information in the environment.

Next, the research team plans to further investigate the impact of vigorous physical action on cognitive function.

“We wanted to understand the role of physical effort-induced arousal and how this arousal might affect response time and inhibition control,” said Azer.

Azer and Zhang were joined in the study by Hyung-Bum Park of UCR and Weizhen Xie of the National Institute of Neurological Disorders and Stroke of the National Institutes of Health. Azer hopes to graduate in June 2023 with a doctorate in psychology, with a focus on cognition and cognitive neuroscience.

This study was supported by grants from the National Institute of Mental Health, the National Institute on Aging, and the National Institute of Neurological Disorders and Stroke.

The title of the paper is “Adverse Effects of Attempted Physical exertion on Dual Tasks of Working Memory in Older Adults.”

The University of California, Riverside is a doctoral research university, a living laboratory for groundbreaking exploration of issues critical to Inland Southern California, the state, and communities around the world. Reflecting California’s cultural diversity, UCR’s enrollment is over 26,000 students. The campus opened a medical school in 2013 and has reached the heart of the Coachella Valley through the UCR Palm Desert Center. The campus has an annual impact of over $2.7 billion on the US economy. To learn more, visit www.ucr.edu.