SAN DIEGO — Children and adolescents usually want to grow up as soon as possible, but most older adults will say they want nothing more than to turn back the clock. Research out of the University of California, San Diego School of Medicine gives both the old and the young reason to envy each other. Scientists say that while older adults usually see a decline in thinking skills, well-being typically increases as we grow older.
More specifically, scientists report that healthy older adults display greater mental well-being than younger adults, but also score lower on cognitive performances. The UCSD team is hopeful that the underlying neural mechanisms identified during this project contributing may inspire new interventions to promote healthy brain function in the future.
“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,” says senior study author Jyoti Mishra, director of the NEATLabs and associate professor of psychiatry at UCSD’s School of Medicine, in a statement..
Researchers sampled a total of 62 healthy younger adults in their 20s, and 54 healthy older adults over 60. Each subject’s mental health was measured via a survey asking about symptoms including anxiety, depression, loneliness, and overall mental wellbeing. Participants also took part in a series of cognitively demanding tasks, all while their brain activity was measured using electroencephalography (EEG).
The brain compensates for cognitive decline as it ages
Results show that young adults experience far more anxiety, depression, and loneliness than older adults. On the other hand, older individuals show higher levels of well-being. Regarding cognition, older adults, unsurprisingly, were much weaker. The EEG recordings provided further insight, detailing greater activity in the anterior portions of the brain’s default mode network among older adults. This brain area is active when we ruminate, daydream, etc., and is usually 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,” Prof. Mishra comments.
So, the default mode network appeared to interfere with cognition. Notably, several other brain regions appeared to improve cognition. Strong cognitive scores among young adults were associated with more activity in the dorsolateral prefrontal cortex, which is part of the brain’s executive control system. For older adults, though, those with strong cognitive scores actually displayed greater activity in their inferior frontal cortex, a brain region known to help guide attention and avoid distractions.
The dorsolateral prefrontal cortex is known to break down as the body ages. Consequently, researchers theorize that the increased inferior frontal cortex activity among cognitively strong older individuals may be an avenue for older minds to compensate during mentally tougher tasks.
Moving forward, researchers are looking into therapeutic interventions that may possibly strengthen these frontal networks. For example, brain stimulation methods that also suppress the default mode network through mindfulness meditation or other similar practices.
“These findings may provide new neurological markers to help monitor and mitigate cognitive decline in aging, while simultaneously preserving well-being,” Prof. Mishra adds. “We tend to think of people in their twenties as being at their peak cognitive performance, but it is also a very stressful time in their lives, so when it comes to mental well-being, there may be lessons to be learned from older adults and their brains.”
The study is published in Psychology and Aging.
