Is it an achievable goal to remain mentally sharp while aging, or is it a pipe dream?It’s entirely possible if you cultivate habits throughout your life that are beneficial to brain function.As a researcher in cognitive neuroscience and the neuropsychology of aging processes, I aim to shed light on the ways we can maintain good cognitive health while aging in light of recent scientific advances.This article is part of our series The Grey Revolution. The Conversation invites you to analyze all the ways the aging baby boom generation is impacting our society, which they have been transforming since their birth. Join us in discovering the changes that are coming, or already underway, in how we house ourselves, work, consume culture, eat, travel, care for ourselves and live. The importance of cognitive reserveOne of the most effective strategies research has identified is developing and maintaining good cognitive reserve.Cognitive reserve refers to the brain’s ability to resist the effects of aging or neurodegenerative diseases without resulting in significant functional decline. This concept is now central to approaches for preventing cognitive decline.In its report Dementia prevention, intervention, and care, updated in 2024, the Lancet highlighted the fact that 45 per cent of dementia cases could be prevented or delayed by addressing 14 modifiable risk factors.These factors include physical inactivity, depression and social isolation.But one of the earliest and most significant factors is having a low level of education.Beyond educationEducation has long been considered the main indicator of cognitive reserve. It reflects prolonged exposure to intellectually stimulating activities that promote the development of effective brain networks.But this view is now considered incomplete. Cognitive reserve is not fixed in childhood or adulthood: it can be built, maintained and even amplified throughout life through different experiences including learning, rich social interactions and cognitively stimulating leisure activities. Specific examples of these activities include playing a musical instrument or complex board games such as chess, or participating in volunteer activities that require planning and problem-solving skills.Understanding cognitive reserveScientific research offers several complementary models for understanding the mechanisms of cognitive reserve.Some focus on the structure of the brain itself, suggesting that characteristics such as the number of neurons influence the brain’s tolerance to damage. This is the brain reserve model, which is based on the idea that some people are born with a greater number of neurons, enabling them to cope better with aging.Others argue that active lifestyles can slow down the effects of brain aging by strengthening biological resilience — for example, the brain’s ability to remain intact and functional as it ages, showing few visible signs of deterioration despite age. This is the brain maintenance model.A third set of models emphasizes the functional flexibility of the brain, which allows it to mobilize its resources differently or recruit alternative neural networks to compensate for age-related losses. This is known as the cognitive reserve model.These different models are part of a common conceptual framework that distinguishes between brain reserve, brain maintenance and cognitive reserve.Each model is based on a specific idea, but they are complementary and supported by empirical data.The cognitive reserve model remains the most widely studied, particularly because of its link to modifiable factors such as level of education and regular participation in cognitively stimulating activities.Cognitive reserve is dynamicThis clarification helps to harmonize research and effectively guide prevention strategies. Above all, it reminds us that far from being a fixed entity, cognitive reserve evolves due to interactions with experience and learning, and can therefore be strengthened throughout life.Recent work supports this dynamic view. A team of Québec researchers, of which I am a member, has shown that structured learning of memory strategies, including the method of loci (associating each piece of information with a familiar place) or mental visualization (transforming information into images to better retain it), can induce significant changes in brain activity.A combination of increases and decreases in activation, including variations in the level of activity in different areas of the brain, was observed in different brain regions during the phases of learning and recalling information. This observation reflects the fact that the use of memory strategies allows for greater functional flexibility in the brain.The results also showed that in more educated individuals, certain regions are activated in a more targeted manner during learning and recall, suggesting that their brains use more effective strategies.Other research has also highlighted the role of education in brain structure and function. A study I conducted with colleagues highlighted an association between years of schooling, volume of grey matter and brain activation in the context of memory. Another study in which I participated showed greater flexibility of activation according to task complexity in more educated individuals.All of this research confirms that cognitive reserve can be developed with experience and modulated by cognitive training at any age.Stimulating your brain while having funIn the same vein, the Engage study by the Canadian Consortium on Aging and Neurodegeneration aims to study the behavioural and neurophysiological effects of cognitively stimulating leisure activities in older adults.This hybrid intervention combines formal cognitive training (memorization strategies, attention) with structured leisure activities such as learning music, a second language or video games.It offers an ecological model — in other words, an approach that is close to real-life conditions, enjoyable and motivating and conducive to sustained engagement.By demonstrating that these natural interventions produce effects comparable to those of traditional cognitive training programmes, which often consist of repetitive exercises done on a computer or on paper to work on functions such as memory or concentration, Engage could transform approaches to preventing age-related cognitive decline.Learning another languageIn my neuropsychology of aging laboratory (NeuroÂge) at the University of Québec at Trois-Rivières (UQTR), we are conducting a complementary project.In collaboration with professors Paul John, from the Department of Modern Languages and Translation, and Simon Rigoulot, from the Department of Psychology, we are exploring the effects of learning English as a second language on cognition and brain activity in older adults.Using a protocol that integrates classes, tutoring and cognitive and electroencephalography measurements, this project aims to document the cognitive and neural benefits of meaningful, motivating and accessible learning.Preliminary results are promising and support the idea that intellectual engagement, even when started later in life, can generate measurable benefits.Maintaining good cognitive health at any age requires a combination of accessible, motivating and stimulating interventions.Cognitive reserve, far from being fixed, is built up throughout life. Advances in research now offer us concrete tools for healthy aging, particularly when it comes to cognitive health.Benjamin Boller received funding from the Fonds de Recherche du Québec.