Adults show lower cognition, better well-being with age
Young and old could 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 better mental well-being but lower cognitive performance than younger adults. The underlying neural mechanisms may inspire novel interventions to promote healthy brain function.
“We wanted to better understand the interplay between cognition and mental health across aging, and whether they rely on activation of similar or different brain areas,” said lead author Jyoti Mishra, PhD, director of NEATLabs. and associate professor of psychiatry at UC San. Diego School of Medicine.
The study sampled 62 healthy young adults in their twenties and 54 healthy older adults over the age of 60. The researchers assessed the participants’ mental health, looking at symptoms of anxiety, depression, loneliness and general mental well-being. Participants also performed several cognitively demanding tasks while their brain activity was measured by electroencephalography (EEG).
The results showed significantly more severe symptoms of anxiety, depression and loneliness in young people and greater mental well-being in older adults. Yet when it comes to cognition, task performance was significantly lower in older adults.
EEG recordings revealed that during the tasks, older people showed greater activity in the anterior parts of the brain’s default mode network. This group of brain areas is typically active when an individual is ruminating, daydreaming, or mind wandering, and is typically suppressed during goal-oriented tasks.
“The default mode network is useful in other contexts, helping us process the past and imagine the future, but it’s distracting when you’re trying to focus on the present to tackle a demanding task with speed and accuracy,” said Mishra.
While the default-mode network seemed to interfere with cognition, several other brain areas seemed to improve it. Better task performance in young adults was associated with greater activity in the dorsolateral prefrontal cortex, part of the brain’s executive control system. In older adults, however, those with better cognitive performance instead showed greater activity in the lower frontal cortex, an area that helps guide attention and avoid distractions.
The dorsolateral prefrontal cortex is known to degrade with aging, so the researchers suggest that the increased activity of the lower frontal cortex may be a way for older people to compensate during these tasks.
The team is now investigating therapeutic interventions to strengthen these frontal networks, such as brain stimulation methods, while removing the network from the default mode through mindfulness meditation or other practices that orient individuals to the present.
“These findings may provide new neurological markers to help monitor and mitigate aging-related cognitive decline, while simultaneously preserving well-being,” Mishra said.
The study may also inspire new ways to approach the mental health of young adults. “We tend to think of people in their twenties as being at the peak of their cognitive performance, but it’s also a very stressful time in their lives, so when it comes to mental wellbeing, there can be lessons to draw from older adults. and their brains,” Mishra said.
The study’s co-authors include Gillian Grennan, Pragathi Priyadharsini Balasubramani, Nasim Vahidi, Dhakshin Ramanathan, and Dilip V. Jeste, all at UC San Diego.
Funding for the study came, in part, from the National Institute of Mental Health (grant T32-MH019934), the NeuroAIDS Interdisciplinary Research Fellowship (grant R25MH081482), the Stein Institute for Research on Aging in UC San Diego, Brain Behavior Research Fund, Kavli Foundation, Burroughs Wellcome Fund Career Award for Medical Scientists, and Sanford Institute for Empathy and Compassion.
Full study: https://doi.org/10.1037/pag0000710
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