Is THIS why our brains slow down as we age? Older people have so many memories stored that when searching for a specific memory, they often retrieve others that are no longer useful, study claims
- Lifetime of knowledge can clutter memories of older adults, researchers suggest
- Older adults have difficulty suppressing information that is no longer relevant
- When searching for a specific memory, they retrieve irrelevant ones along with it
- But study claims this life experience can aid with creativity and decision-making
It is a sad fact of life that as we age many of us have difficulties retrieving memories.
But now researchers think they know why — it’s because older people’s brains allocate more space to knowledge built up over the years, meaning there is more material to navigate when trying to access memories.
The study found that the older we get the more difficulty we have suppressing information that is no longer relevant.
It means that when searching for a specific memory, older people often retrieve other, irrelevant memories along with it.
It is a sad fact of life that as we age many of us have difficult retrieving memories. A new study suggests it’s because older people’s brains allocate more space to knowledge built up over the years, meaning there is more material to navigate when trying to access memories (stock)
HOW A FAMOUS AMNESIAC TAUGHT US HOW WE FORM LONG-TERM MEMORIES
Beginning in the 1950s, studies of the famous amnesiac patient Henry Molaison revealed that the hippocampus is essential for forming new long-term memories.
Molaison, whose hippocampus was damaged during an operation meant to help control his epileptic seizures, was no longer able to store new memories after the operation.
However, he could still access some memories that had been formed before the surgery.
This suggested that long-term memories of specific events are stored outside the hippocampus.
Scientists believe these memories are stored in the neocortex, the part of the brain also responsible for brain functions such as attention and planning.
That was the finding of research by experts at Harvard University, Columbia University and the University of Toronto, who looked at several behavioural and neuroimaging studies.
‘Older adults have greater knowledge of the world but generally show poorer episodic memory performance on many laboratory-based tasks relative to young adults,’ the authors wrote in their paper.
‘We propose that this paradox can be accounted for, at least partially, by the uniquely cluttered/enriched memory representations of older adults.’
They added: ‘With these cluttered or rich representations, older adults are more likely to activate excessive information.
‘This, in turn, can pose retrieval difficulties for target information (and negatively impact episodic and working memory tasks).
However, while this wealth of life experience can make memory retrieval challenging, the researchers said it also has its upsides because it can boost creativity and decision-making.
‘Evidence suggests that older adults show preserved, and at times enhanced, creativity as a function of enriched memories,’ the researchers said.
They also suggest that prior knowledge can help older adults when it comes to decision-making, where they can pull on their accumulated wisdom.
The research found that when given a cognitive task, older people rely more heavily on previous knowledge than younger adults do.
This graphic shows how, compared to younger adults, older people’s memories are cluttered with no-longer-relevant details that were never suppressed, prior knowledge, and irrelevant or distracting information
With further research and increased understanding of how memory works in older adults, the experts said they were hopeful that they may be able to find new ways to help those with crowded memoryscapes.
They added: ‘It is possible that the increased binding and richer encodings of older adults can even be leveraged to improve older adults’ learning and memory.
‘Future research can investigate how negative and positive outcomes of cluttered/enriched memory representations converge to influence functional behaviour in everyday life.’
The study has been published in the journal Trends in Cognitive Sciences.
HOW HAS THE SHAPE OF OUR BRAINS EVOLVED OVER TIME?
New research suggests key evolutionary changes in our brain shape occurred 100,000-35,000 years ago. Stock image
Researchers at Germany’s Max Planck Institute for Evolutionary Anthropology discovered that key evolutionary changes in our brain shape occurred roughly 100,000 to 35,000 years ago
The Homo sapiens brain took on a globe-like shape that’s ’rounder and less overhanging’
By contrast, our Neanderthal ancestors’ brains had a more elongated shape
The evolution of our brain shape coincided with major developments in behavior, as Homo sapiens began to:
- Build tools
- Develop a working and long-term memory
- Possess self-awareness
- Use language
- Plan activities
- Understand numbers
- Pay attention to their surroundings
- Develop emotions
The brain began to look more like a globe as a result of bulging in the parietal area and the cerebellum