How quick you react can predict life span

THE reaction times of older people may predict how long they have to live, a study found.

Those who have greater inconsistency in their responses were found to have a lower surival time. The same could not be said of simply being slow or quick to react.

Researchers examined 861 people aged between 70 and 90 over eight years. They gave participants computerised tests which required them to select a coloured square on a screen as quickly as possible.

The team discovered that inconsistent responses predicted survival time even after accounting for other factors such as age, sex, cardiovascular risk and cognitive decline.

Dr Nicole Kochan, from the University of New South Wales in Australia, said that erratic reactions are possibly linked to the efficiency of brain process- ing mechanisms. As people get older, the brain’s ability to process information declines – leading to erratic responses.

She added that these reaction times appear to become even more exaggerated as a person gets closer to death.

Dr Kochan said: ‘Our findings suggest that greater reaction time variability is a behavioural marker that uniquely predicts shorter time to death.

‘Importantly, the predictive strength of reaction time variability was virtually unchanged when we removed participants who developed dementia over the subsequent eight years.’

Co-author Perminder Sachdev said: ‘Further research exploring the mechanisms involved is needed, including possible links between reaction time variability, cognitive decline and structural brain changes.’

The findings were published in the medical journal PLOS ONE.

‘Structural brain changes’