Human brains cope with aging by recruiting other brain regions to help

In the quest to understand how the human brain copes with aging, a new study reveals compelling evidence that older individuals can counteract cognitive decline by leveraging different brain regions to maintain mental performance.

This discovery sheds light on the remarkable adaptability of the brain, offering hope for strategies to preserve cognitive function with age.

The aging brain: Navigating cognitive decline

As we grow older, our brain undergoes a natural process of atrophy, characterized by the loss of nerve cells and connections.

This degeneration can lead to a deterioration in brain function. However, not everyone experiences cognitive decline to the same extent, prompting scientists to investigate the factors that contribute to better brain health in some individuals.

The conventional wisdom suggests that some brains can mitigate the effects of aging by enlisting additional brain areas to assist in cognitive tasks.

Although previous brain imaging studies have demonstrated this recruitment process, its impact on task performance and its potential to provide new insights into cognitive strategies remained unclear.

A collaborative study between the University of Cambridge and the University of Sussex has now provided strong evidence that activating supplementary brain regions enhances cognitive performance in older adults.

Harnessing the brain’s adaptive aging power

Dr. Kamen Tsvetanov is the a lead researcher and Alzheimer’s Society Dementia Research Leader Fellow at the University of Cambridge.

He emphasized the importance of understanding why some older individuals maintain their the ability to solve new problems better than others.

“Our ability to solve abstract problems is a sign of so-called ‘fluid intelligence’, but as we get older, this ability begins to show significant cognitive decline,” explained Dr. Tsvetanov.

“Some people manage to maintain this ability better than others. We wanted to ask why that was the case – are they able to recruit other areas of the brain to overcome changes in the brain that would otherwise be detrimental?”

The research aimed to explore whether these individuals could engage different parts of the brain to offset age-related changes.

The study involved 223 participants, ranging from 19 to 87 years old, from the Cambridge Centre for Ageing & Neuroscience (Cam-CAN).

While undergoing functional magnetic resonance imaging (fMRI), volunteers were tasked with identifying the odd-one-out in a series of puzzles. This setup allowed the researchers to observe patterns of brain activity related to changes in blood flow.

Role of the cuneus in cognitive compensation

Results confirmed that problem-solving abilities generally decline with age. However, analysis through machine learning identified two brain regions — the cuneus at the back of the brain and a frontal cortex area — that were more active in older participants and correlated with better task performance.

Notably, only the cuneus’ activity was more strongly linked to task performance in older compared to younger volunteers, suggesting it plays a unique role in compensating for cognitive decline.

The cuneus is typically associated with visual focus, a critical factor as older adults often struggle with visual memory, such as remembering intricate puzzle pieces.

The study suggests that increased activity in the cuneus may represent a compensatory strategy to overcome these visual memory challenges.

Implications and future study

Dr. Ethan Knights, from the Medical Research Council Cognition and Brain Sciences Unit at Cambridge, highlighted the significance of this compensation mechanism.

“Now that we’ve seen this compensation happening, we can start to ask questions about why it happens for some older people, but not others, and in some tasks, but not others,” Knights said.

“Is there something special about these people – their education or lifestyle, for example – and if so, is there a way we can intervene to help others see similar benefits?”

Understanding these underlying factors could lead to interventions that help more people experience similar cognitive benefits.

Dr. Alexa Morcom from the University of Sussex’s School of Psychology and Sussex Neuroscience research center, pointed out that these findings challenge previous assumptions about the reliance on the multiple demand network.

“This new finding also hints that compensation in later life does not rely on the multiple demand network as previously assumed, but recruits areas whose function is preserved in aging,” said Marcom, echoing the sentiment.

Aging brains and cognitive resilience

This important study propels our understanding of the aging brain forward, revealing that older individuals can indeed enhance their cognitive performance by engaging additional brain regions, notably the cuneus.

This discovery challenges our assumptions about the brain’s adaptive mechanisms in combating aging and cognitive decline, while expanding research into personalized strategies for cognitive preservation.

By highlighting the brain’s capacity to compensate for age-related changes, the findings from Dr. Kamen Tsvetanov and his team offer hope for developing interventions that could empower more people to maintain mental sharpness well into their later years, ultimately enriching the quality of life for the aging population.

The full study was published in the journal eLife.