The concept that cognitive health can be preserved or improved is often expressed as “use it or lose it.” Numerous modifiable risk factors are associated with “losing” cognitive abilities with age, and a cognitively active lifestyle may have a protective effect.
But what is a “cognitively active lifestyle” — do crosswords and Sudoku count?
One popular approach is “brain training.” While not a scientific term with an established definition, it “typically refers to tasks or drills that are designed to strengthen specific aspects of one’s cognitive function,” explained Yuko Hara, PhD, director of Aging and Alzheimer’s Prevention at the Alzheimer’s Drug Discovery Foundation.
Manuel Montero-Odasso, MD, PhD, director of the Gait and Brain Lab, Parkwood Institute, London, Ontario, Canada, elaborated: “Cognitive training involves performing a definitive task or set of tasks where you increase attentional demands to improve focus and concentration and memory. You try to execute the new things that you’ve learned and to remember them.”
In a commentary published by this news organization in 2022, neuroscientist Michael Merzenich, PhD, professor emeritus at University of California San Francisco, said that growing a person’s cognitive reserve and actively managing brain health can play an important role in preventing or delaying Alzheimer’s disease. Important components of this include brain training and physical exercise.
Brain Training: Mechanism of Action
Dr. Montero-Odasso, team leader at the Canadian Consortium on Neurodegeneration in Aging and team co-leader at the Ontario Neurodegenerative Research Initiative, explained that cognitive training creates new synapses in the brain, thus stimulating neuroplasticity.
“When we try to activate networks mainly in the frontal lobe, the prefrontal cortex, a key mechanism underlying this process is enhancement of the synaptic plasticity at excitatory synapses, which connect neurons into networks; in other words, we generate new synapses, and that’s how we enhance brain health and cognitive abilities.”
The more neural connections, the greater the processing speed of the brain, he continued. “Cognitive training creates an anatomical change in the brain.”
Executive functions, which include attention, inhibition, planning, and multitasking, are regulated predominantly by the prefrontal cortex. Damage in this region of the brain is also implicated in dementia. Alterations in the connectivity of this area are associated with cognitive impairment, independent of other structural pathological aberrations (eg, gray matter atrophy). These patterns may precede structural pathological changes associated with cognitive impairment and dementia.
Neuroplasticity changes have been corroborated through neuroimaging, which has demonstrated that after cognitive training, there is more activation in the prefrontal cortex that correlates with new synapses, Dr. Montero-Odasso said.
Henry Mahncke, PhD, CEO of the brain training company Posit Science/BrainHQ, explained that early research was conducted on rodents and monkeys, with Dr. Merzenich as one of the leading pioneers in developing the concept of brain plasticity. Dr. Merzenich cofounded Posit Science and is currently its chief scientific officer.
Dr. Mahncke recounted that as a graduate student, he had worked with Dr. Merzenich researching brain plasticity. When Dr. Merzenich founded Posit Science, he asked Dr. Mahncke to join the company to help develop approaches to enhance brain plasticity — building the brain-training exercises and running the clinical trials.
“It’s now well understood that the brain can rewire itself at any age and in almost any condition,” Dr. Mahncke said. “In kids and in younger and older adults, whether with healthy or unhealthy brains, the fundamental way the brain works is by continually rewiring and rebuilding itself, based on what we ask it to do.”
Dr. Mahncke said.