Now, researchers in the US are claiming that computerised brain training can reduce the risk of dementia by 29%.
The programme involved training people to boost the speed and accuracy of their visual attention. For instance, the user would be expected to identify an object, such as a car, at the centre of their gaze while at the same time locating a specific road sign flashing intermittently at the periphery of their vision.
Photo credit: Posit Science
As the exercise goes on, the road sign, or other target, would flash more briefly, demanding extra attention and processing skills.
The study, published in the journal Alzheimer's and Dementia: Translational Research and Clinical Interventions, involved 2,802 healthy older adults who were monitored for 10 years as they aged from an average of 74 years to 84.
During this period, 260 cases of dementia occurred.
At the start, participants were randomly assigned into 1 of 4 groups. Members of 3 of the groups were either given instruction on memory strategies, instruction on reasoning strategies, or individualised computerised speed of processing training.
Members of all of these groups were offered up to 10 initial sessions of training, each lasting 60 to 75 minutes, over the first 6 weeks of the study. Booster training sessions were available at later stages.
The fourth group acted as a 'control' and involved no training.
The research team from the University of South Florida found that those who completed more speed training sessions had lower risk of dementia.
Among those who completed 13 or more sessions, the risk of dementia for the computerised brain-training group was lowest at 5.9%, compared to 9.7% for the group focusing on memory strategies and 10.1% for the memory and reasoning strategy group.
The control group, which did not engage in any training, had a dementia rate of 10.8%.
The authors speculate that brain-training might protect against dementia by increasing 'brain reserve'.
Several independent experts have noted in statements that the researchers admit their study lacked any clinical diagnoses of dementia.
Rob Howard, professor of old age psychiatry at University College London (UCL) says he finds it "surprising" that the risk of dementia could be reduced after 10 years following only a few hours of cognitive training.
"I find it implausible that such a brief intervention could have this effect and it is worth bearing in mind that the results could have occurred by chance or as a consequence of uncontrolled confounding factors," he says. "On the basis of this study, I won't be recommending speed of processing training to my friends or patients."
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