Health and Beauty

Dementia Unsw

Erratic responses, not speed, better predictor of death in older people

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Lead author and head of CHeBA’s Neuropsychology group, Dr Nicole Kochan, said the study was the first to comprehensively account for effects of overall cognitive level and dementia on the relationship between intraindividual variability of reaction time and mortality.

"Our findings suggest that greater intraindividual reaction time variability is a behavioural marker that uniquely predicts shorter time to death," said Dr Nicole Kochan.

"Importantly, the predictive strength of intraindividual reaction time variability was virtually unchanged when we removed participants who developed dementia over the subsequent eight years. This suggests that variability of reaction time is an independent risk factor and not simply a corollary of general cognitive decline or neuropathological disturbances associated with dementia."

The study examined 861 community-dwelling participants aged 70-90 years from CHeBA’s Sydney Memory and Ageing Study (MAS) over eight years.