Mental ability declines as we get older
As people age their ability to process and remember information declines, but research shows this may be partly reversible.
US scientists have found older people are unable to spontaneously use areas of the brain which aid memory processing.
Writing in the journal Neuron, Randy Buckner, who carried out the study, said: "For a long time we have known that as people age they start to have difficulties with higher-level controlled cognitive processes."
Studies have shown this loss of mental ability is partly due to reduced functioning of the frontal cortex - the region of the brain responsible for higher-level intellectual processing.
Mr Buckner said older people show milder versions of the difficulties experienced by people who have suffered damage to their frontal cortex.
Improved performance
He and his team devised a test in which his respondents were asked to remember a series of words.
A total of 62 people took part, the younger adults were in their 20s and the older ones in their 70s and 80s and without any signs of dementia disorders such as Alzheimer's disease.
Their brain activity was "photographed" using a magnetic resonance imaging machine which can precisely map enhanced blood flow in specific areas of the brain.
They tried to remedy this by asking the older subjects to make an association for the words and categorise them as either abstract or concrete.
Mr Buckner said: "When we did that, the older adults showed increased activity in these frontal regions and their memory performance improved.
"The situation with regard to overcoming memory deficits in ageing is much more promising than we thought.
"It could have been the case that the frontal regions in the older adults had atrophied or undergone cellular deterioration to the extent that they were inaccessible to these individuals.
"But that was not the case."
Mr Buckner and his colleagues suggest that mental training could encourage older adults to use available frontal cortex areas to improve memory.
Anxieties
They are now working on what sort of training would be most effective.
The charity, Research Into Ageing has welcomed the results of the study.
A spokeswoman said: "We are lifting the lid on what's going on inside our brains.
"Many people worry about losing their memory and if we can understand what's going on inside the brain, it is the first step to doing something about it.
"It could lead to the development of treatments.
"Anything that reduces people's anxieties about their mental health as they get older is a good thing."