Cognitive training benefits older people

84 people participated in the experiment: 35 young adults (18-30 years old) and 49 elderly (60+ years old). Everyone completed one of two types of training sessions — six sessions of 45-60 minutes over four weeks.

The first group performed a dual task exercise: Participants had to simultaneously select images with both hands on a tablet. With their left hand, they chose an animal (snake, dog, or bird), and with their right, a celestial body (planet, star, or sun). According to Blanchett, it’s like driving a car while simultaneously searching for an address: the brain has to coordinate two streams of information in parallel.

The second group trained working memory (n‑back task). Numbers appeared on the screen, and participants had to indicate whether the current number matched the one, two, or three steps back in sequence. For example, in the “2-back” mode, when the sequence is “3, 7, 3, 5, 3,” the participant must recognize that the last “3” matches the number two positions earlier. The greater the distance between the numbers, the more challenging the task becomes.

After completing the training sessions, the participants were re-evaluated with new stimuli: different sets of images for the task-combining test and letters instead of numbers for the n-back test. This ensured that the changes reflected genuine improvements rather than mere memorization.

All groups showed significant improvements after training, but the most interesting results were found in the older participants. The performance on the task-switching test improved after the corresponding training in both age groups. However, the working memory training (n-back) had an impact on the task-switching test results, but only in the older participants. In other words, the improvement in cognitive functions due to working with numerical sequences helped the older participants to better handle simultaneous performance of two tasks that were not initially related to the trained skill.

However, the performance of the most difficult level of the n-back test (3-back) improved only after the same type of training. Task-switching training did not significantly improve the performance of the n-back test in either young or older participants.

The researchers suggest that the reason for the stronger effect in older participants is a process known as neural compensation. As we age, our brains begin to use more working memory resources to manage multiple tasks simultaneously. “We’ve noticed that as we age, our brain’s functioning becomes less specific,” Blanchette explains. “We rely on different mechanisms to complete tasks, and when performing multiple tasks simultaneously, we rely more heavily on mechanisms related to working memory.”

Since the n-back training strengthened working memory, it helped older individuals better coordinate multiple actions simultaneously. However, Blanchette emphasizes that this interpretation is still hypothetical and requires further validation through studies that combine behavioral measurements and neuroimaging.

The scientist concludes that it is not enough to limit cognitive training to one type of exercise in order to maintain and improve cognitive function in older people — it is necessary to diversify them. Professor Berer perceives the results with optimism: “Cognitive abilities change with age, but we can influence it. This is good news!”

Blanchett and Berer advocate programs that include several components. In her dissertation, Blanchett plans to further explore this idea by studying people with heart failure, who have a 40-60% risk of developing cognitive impairment without intervention.