What is Cognitive Ageing?

When you make a cup of tea, use the internet or read a book, you're using your·cognitive abilities. Cognitive abilities are the mental skills you need to carry out any task from the most simple to the most complex. These mental skills include awareness, information handling, memory and reasoning.

As we get older, our cognitive abilities gradually deteriorate. A certain amount of·cognitive decline is a normal part of ageing. Some people, however, will experience a severe deterioration in cognitive skills, leading to dementia. This can make it impossible to cope with ordinary day-to-day tasks.The Centre's research affects everyone in the UK because we're all part of an ageing population. Because we're living longer, it's more likely that we, or someone close to us, will suffer from dementia.

People differ greatly in the degree to which their brains, and the rest of their bodies, decline with age. ‘Normal cognitive ageing’ is a crude average; it hides the fact that there are more or less successful trajectories of cognitive change as people grow older. Identifying the risk factors for, and mechanisms of, individual differences in age-related cognitive decline is amongst the greatest challenges to improving the health of older people. The spectrum of decline ranges from normal cognitive ageing to the dementias.

Cognitive ageing is complex: there is little age-related decline in some mental functions—such as vocabulary, some numerical skills, and general knowledge—but other mental capabilities decline from middle age onwards, or even earlier. The latter include aspects of memory, executive functions, processing speed, reasoning, and multitasking. All of these mental functions are critical for carrying out everyday activities, living independently, and for general health and wellbeing. A further three findings are striking. First, different aspects of age-related decline occur together. Second, slowed speed of information processing accounts for a large proportion of age-related decline in all cognitive domains. This slowing of speed of brain processing begins in young adulthood. Third, the ability to schedule and undertake multiple everyday activities appears to be sensitive to ageing, and particularly striking impairments in dual-tasking or multitasking appear to signal the onset of dementia. There is a massive explanatory gap in this increasingly large health problem: the biological foundations of cognitive ageing across the spectrum, slowed information processing, and multitasking, are unknown.