Dementia held at bay by those with adaptive brains

The brains of older individuals who retain good memory and cognitive skills handle information differently than those who experience failing memory and neural decline.

Research from Trinity College Dublin's institute of neuroscience helps explain the kind of brain function that underlies successful ageing.

Brain activity scans of those who performed better in learning and memory tests showed their brain physiology had changed from when they were younger, said Dr Paul Dockree, an assistant professor at Trinity's school of psychology.

Those who performed less well did not show theses signs of adaptive change, he said. Dr Dockree was lead author of a research paper published in the journal Brain and Cognition.

“We were interested in the idea of exploring what underlies successful ageing,” he said. “We were looking for markers for the early signs of dementia so we could use them in a predictive way. We were also trying to characterise features of elderly people who had preserved their mental function.”

The research team divided a group of 43 individuals with an average age of 70 based on high or low memory performance in standard tests.

“The question was do successfully ageing individuals simply retain this function like when they were young or are they doing something else, something more flexible that offsets atrophy in the brain. The findings suggest the latter,” he said.

The key was what was going on in the brain while learning, he suggested. Their neural activity was not like that of younger people, there were quite surprising adaptive changes in the brain while learning.

It is encouraging because it shows markers for success, Dr Dockree said. "The question which this research gives rise to is what factors in mid-life or even earlier can promote this kind of adaptable and flexible brain activity. "

It is already known that exercise is able to help keep the brain functioning well. And being bilingual or even trilingual also contributes a positive benefit according to research from groups in Toronto and in Edinburgh. Having a command of two languages delays the onset of dementia by 4.2 years compared to monolinguals, Dr Dockree said.

Understanding how these compensatory patterns emerge in the brain, and discovering their relationship to life-long experiences or activities that can promote these adaptive changes, offers hope for the goal of prolonging healthy aging, he added.