We often measure brain health from the outside, such as how well someone remembers a name or how quickly they solve a puzzle. But a new study from McGill University is giving us a window into something deeper: the actual chemistry of the aging brain.
The study focused on the cholinergic system, a network of brain cells that uses the neurotransmitter acetylcholine to support attention, learning, and memory. As people age, this system gradually deteriorates, which is a primary reason older adults struggle with concentration and working memory, and a key factor in diseases like Alzheimer's.
The trial enrolled 92 healthy adults aged 65 and older, who were randomly assigned to either the game-like brain-training app BrainHQ or standard recreational computer games for 30 minutes per day over 10 weeks. To measure changes inside the brain, researchers used a specialized PET scan, available at only a handful of centers worldwide, that captures cholinergic activity in real time.
The results were unprecedented. After 10 weeks, those who used BrainHQ showed measurable increases in cholinergic activity in the anterior cingulate cortex, a region of the brain central to attention and memory. The magnitude of that improvement was equivalent to reversing roughly ten years of age-related decline, the first time any intervention, including medication, had achieved this in humans.
Researchers emphasized that not all brain activities produce this kind of effect. Passive activities like casual reading or standard crossword puzzles do not place the same adaptive demands on the brain as purpose-built cognitive training. The BrainHQ exercises get harder as users improve, specifically targeting the brain's processing speed and driving genuine neuroplasticity.
The brain is not fixed. It is responsive, adaptable, and capable of renewal.
Citations:
McGill University Newsroom. October 14, 2025. https://www.mcgill.ca/newsroom/channels/news/researchers-neuro-show-brain-exercise-yields-benefits-368265
ScienceDaily. October 29, 2025. https://www.sciencedaily.com/releases/2025/10/251029002858.htm