At Montreal's EPIC Center, a team of researchers discovered something unexpected: when older adults practiced brain training exercises that seemed designed for a specific mental task, they ended up becoming better at something entirely different—a finding that could reshape how we think about cognitive health in later life.
The study, led by doctoral student Caroll-Ann Blanchette under the supervision of Professor Louis Bherer at UdeM's Department of Medicine, tracked 84 participants across two age groups: 35 young adults between 18 and 30, and 49 older adults aged 60 and over. Each participant completed one of two intensive training programs over four weeks, with six sessions lasting 45 to 60 minutes each. The question driving the research was deceptively simple: when cognitive training sharpens one skill, does it actually improve other mental abilities too?
The first training involved what researchers called a "dual task"—the kind of mental juggling we do every day. Participants sat at a tablet and used both hands simultaneously, selecting images of animals with their left hand while identifying celestial bodies with their right. "It's a bit like driving while looking up an address," Blanchette explained. "The brain has to coordinate two streams of information in parallel." The second group practiced an "n-back" task that taps working memory, identifying whether numbers on a screen matched ones that had appeared one, two, or three positions earlier in a sequence. The greater the gap, the harder the task.
What happened next surprised the researchers. After training on the n-back task—exercises focused entirely on number sequencing and working memory—older adults showed significant improvement at the dual-task test with entirely new stimuli. This is the key insight: training that strengthened their ability to remember sequences somehow made them better at juggling two simultaneous activities. Young adults showed no such transfer effect.
The reverse didn't hold true. Dual-task training improved performance on dual-task tests across both age groups, but it didn't significantly help either younger or older participants improve at the most difficult n-back levels.
Blanchette and Bherer's explanation centers on what neuroscientists call neural compensation. As the brain ages, it adapts by mobilizing more working memory resources to manage multiple activities at once. Unlike younger brains, which maintain specialized networks for different tasks, older brains tend toward a more integrated, flexible approach. When n-back training strengthened working memory itself, older adults could apply that newly sharpened resource to entirely different challenges—like coordinating two simultaneous tasks.
The practical implication is clear and hopeful. A single type of cognitive training, no matter how targeted, isn't sufficient to maintain or improve cognitive function in older adults. "You have to vary the training in order to maintain or improve cognitive functioning," Blanchette said. The brain's remarkable plasticity in later life means that investment in diverse mental challenges pays dividends across multiple domains of thinking and daily functioning.
For those concerned about cognitive aging, the message from Montreal is encouraging: cognition does change with age, but it remains trainable. The brain in later life isn't locked into decline—it's adaptable, responsive, and capable of surprising gains when challenged in the right ways.