At the time, evidence for the practical benefits of these activities was limited. But recently, neuroscience has identified a growing list of activities that appear to support brain health, including learning a language, playing music, walking and mastering a new skill.
This raises a broader question: if these experiences strengthen the brain, could they be combined into something more deliberate – a workout designed for the mind?
“Right now, we only focus on the brain when something goes wrong. But we are finding that there may be things we can do for prevention,” said Sandra Bond Chapman, professor of behavioural and brain sciences at the University of Texas at Dallas. Several recent studies have fuelled interest in brain training. Researchers at McGill University found that older adults who completed 30 minutes of brain training daily for 10 weeks showed improvements in the brain’s cholinergic system, which supports learning and memory. Another study found cognitive training could physically reorganise the adult brain, while a 20-year follow-up of a landmark clinical trial reported that adults aged 65 and older who completed a speed-of-processing programme had a 25 per cent lower risk of developing dementia than those in the control group.
The field gained further attention at the Alzheimer’s Association International Conference, where researchers presented findings from the largest clinical trial investigating whether computerised brain-training exercises can reduce age-related cognitive decline.
Funded with more than $50 million from the National Institutes of Health, the study reflects growing interest in an intervention that is inexpensive, scalable and widely accessible. The July study, conducted by researchers at Clemson University, the Medical University of South Carolina and Penn State, involved 53 participants. Although small, it was a randomised controlled trial, regarded as the gold standard in clinical research.
How the training worked
Researchers say only certain types of cognitive training appear to produce meaningful benefits, and responses may differ between men and women. Aaron Seitz, professor of psychology, game design and physical therapy at Northeastern University, cautioned that some companies continue to oversell the science. While there is no broad scientific consensus that brain-training games work, he said the evidence warrants further investigation.
Participants were randomly assigned to one of three groups and spent two to three hours a week completing computerised exercises for about three months.
One group completed top-down thinking exercises designed to strengthen planning, reasoning and attention. A second group focused on bottom-up training, which targeted processing speed and visual attention through tasks requiring participants to quickly identify and remember visual information under increasing time pressure.
The third group acted as a control, spending the same amount of time playing familiar computer games, including Connect Four, Solitaire and word searches.
Measuring brain health
Researchers collected blood samples before and after the training to measure two forms of amyloid beta, a protein closely linked to Alzheimer’s disease. One form, amyloid beta 42, is especially prone to forming the plaques found in the brains of people with the disease.
Sandra Bond Chapman, founder and chief director of the Centre for BrainHealth at the University of Texas at Dallas, is also helping develop the BrainHealth Index, which combines executive function, emotional wellbeing and social connectedness into a single score to monitor changes in brain health over time.
Speed matters
All three groups spent similar amounts of time exercising their brains. However, only the speed-training group showed favourable changes in Alzheimer’s-related biomarkers.
Researchers linked the finding to the brain’s cholinergic system, a network of cells that supports attention, learning and memory. The system naturally declines with age but deteriorates more rapidly in Alzheimer’s disease.
“Our theory is that speed-processing exercises stimulate the cholinergic system in a way that influences biological pathways involving tau and amyloid,” said Hye Won Chai, the study’s lead author.
The findings are consistent with the McGill University study, which also found that brain training benefited the cholinergic system. Etienne de Villers-Sidani, associate professor of neurology and neurosurgery at McGill University, said processing speed declines earlier than many other forms of knowledge, such as vocabulary, which often remain stable with age.
He said this may explain why word games are less effective than exercises designed to improve processing speed. However, he stressed that crosswords and Sudoku remain mentally engaging and enjoyable.
Men, women and age
The study also suggested men and women may respond differently to cognitive training. Speed-processing exercises altered Alzheimer’s-related amyloid biomarkers in men, while women showed changes in the depth of cortical folds in brain regions linked to memory and attention. Researchers said the significance of these differences remains unclear. Age also appears to influence the benefits of brain training. Seitz said the greatest improvements are often seen in people with the most room for improvement, particularly older adults with less cognitively stimulating lifestyles.
A review published in the Lancet last year found the greatest cognitive benefits occurred when brain training was combined with other lifestyle measures, especially physical exercise, rather than used alone.
The bottom line is that the evidence resists easy conclusions .“It’s kind of messy,” Seitz said.
