Increased frontal brain activity in older adults is due to reduced efficiency, a recent study suggests
A study led by Dr Alexa Morcom has found that increased frontal brain activity in healthy older adults reflects reduced efficiency rather than a way to maintain thinking skills. The results contradict a leading theory in the neuroscience of ageing.
Putting the theory to the test
The Posterior-to-Anterior Shift in Aging (PASA) theory proposes that the distribution of brain activity shifts towards the front of the brain in later life to compensate for the typical age-related decline in cognitive functions such as memory.
Alexa Morcom and Richard Henson tested predictions of this theory by analysing fMRI data from healthy adults aged 19-88 years. In two separate experiments, brain imaging data were acquired while people carried out a long-term or a short-term memory task. Consequently, they could see that the elevated prefrontal cortex activity did not carry additional information related to the memory tasks.
In contrast to the PASA theory, these results suggest that increased prefrontal cortex in ageing is less specific or less efficient and may underlie age-related decline of thinking skills. The study instead supports the idea that the extent to which an older brain operates like a younger one is a key determinant of the function of thinking skills in old age. So keeping your brain as youthful as possible is probably the best way to maintain thinking skills in later life!
Read the full article in the Journal of Neuroscience:
Increased Prefrontal Activity with Aging Reflects Nonspecific Neural Responses Rather Than Compensation
Looking after your thinking skills
Psychology researchers at Edinburgh created this video with the charity Age UK on how to stay sharp in later life:
About Alexa Morcom
Alexa Morcom is a Senior Lecturer in Psychology at the University of Edinburgh. Her research centres on the cognitive neuroscience of memory and ageing.