Your daily crossword is still a flex. But scientists are testing a more focused question: Can you train an aging brain to process information faster — and potentially change its trajectory?

• 🧩 Why it matters: A growing body of research suggests certain kinds of cognitive exercises can produce measurable changes in the brain. One long-running trial even linked a specific type of training to fewer dementia diagnoses, Axios' Natalie Daher writes.

💡 The evidence: Recent studies highlighted by The Washington Post (gift link) suggest that targeted cognitive training may affect systems involved in attention and memory as well as brain structure.

⚡ Zoom in: A separate, much smaller randomized clinical trial presented last month at the Alzheimer's Association International Conference offers a clue about what might be happening biologically.

• Researchers from Clemson University, the Medical University of South Carolina and Penn State randomly assigned 53 participants to three groups that trained two to three hours a week for about three months.

🔬 One group practiced higher-order thinking, such as planning, reasoning and shifting attention.

• Another concentrated on processing speed and visual attention. In one exercise, for example, participants had to identify a vehicle flashed briefly in the center of a screen while also remembering where a Route 66 sign appeared.
• A third, active-control group played familiar games, including Solitaire, word searches and a version of Connect Four.

Before and after the training, researchers took blood samples to measure two forms of amyloid beta, a protein closely associated with Alzheimer's disease.

• Only the speed-training group showed favorable shifts in those Alzheimer's-related biomarkers.

🧪 Reality check: The science is still early. Researchers don't yet know whether those changes translate into better everyday functioning or lower disease risk.

• There's still no single accepted measure of a "healthy" brain, and brain training isn't a substitute for exercise or other healthy habits.

The bottom line: Keep up your Sudoku if you enjoy it.

• The bigger question now: Can scientists figure out which mental workouts actually help our brains age better?

🌊 Morning blue gives way to golden light over San Sebastián's harbor in Spain's Basque Country.

• Thanks to reader Jeff Turner of Little Washington, Va., for sending these along.