Young and old can learn a thing or two from each other, at least when it comes to mental health and cognition.
In a new study published on September 12, 2022 in psychology and aging, researchers at the University of California San Diego School of Medicine found that healthy older adults show greater mental well-being but lower cognitive performance than younger adults. Underlying neural mechanisms may inspire new interventions to promote healthy brain function.
We wanted to better understand the interaction between cognition and mental health across aging, and whether they depend on the activation of similar or different brain regions. “
Jyoti Mishra, PhD, first author, director of NEATLabs and associate professor of psychiatry at UCSD School of Medicine
The study collected samples from 62 younger healthy adults in their 20s and 54 healthy older adults over the age of 60. The researchers assessed the participants’ mental health, surveying symptoms of anxiety, depression, loneliness, and overall mental health. Participants also performed several demanding cognitive tasks while measuring brain activity using electroencephalography (EEG).
The results showed significantly worse symptoms of anxiety, depression, and loneliness in young adults and increased mental health in older adults. However, when it came to cognition, task performance was significantly lower in older adults.
EEG recordings revealed that during the tasks, older adults showed greater activity in the frontal parts of the brain’s default mode network. This group of brain regions is usually active when an individual is ruminating, daydreaming, or mind-wandering, and is usually suppressed during goal-directed tasks.
“The default mode network is useful in other contexts, as it helps us process the past and imagine the future, but it gets distracting when you’re trying to focus on the present to tackle a difficult task quickly and accurately,” Mishra said.
While the default mode network appears to interfere with cognition, many other areas of the brain appear to improve it. Better task performance in younger adults was associated with greater activity in the dorsolateral prefrontal cortex, part of the brain’s executive control system. However, in the elderly, those with better cognitive performance showed greater activity in the inferior frontal cortex, an area that helps direct attention and avoid distractions.
The dorsolateral prefrontal cortex is known to degrade with age, so researchers suggest that increased inferior prefrontal cortex activity may be a way for older adults to compensate during these tasks.
The team is now looking at therapeutic interventions to strengthen these frontal networks, such as brain stimulation methods, while also suppressing the default mode network through mindfulness meditation or other practices that direct individuals to the present.
“These findings may provide new neurological markers to help monitor and mitigate cognitive decline in aging, while at the same time maintaining well-being,” Mishra said.
The study may also inspire new ways to address the mental health of younger adults. “We tend to think of people in their twenties as being at their peak cognitive functioning, but it’s also a very stressful time in their lives, so when it comes to mental health there may be lessons to be learned from older adults,” Mishra said.