A 20-Year Study Found That Only One Type Of Brain Training Works
5 weeks of brain training could lower your dementia risk by 25%
Hollif
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February 14, 2026
Image by Audrey Shtecinjo / Stocksy February 14, 2026 You've probably seen various ads for brain training apps that promise to keep your mind sharp as you age. Maybe you've even downloaded a few, or you're loyal to your daily crossword. However, a groundbreaking 20-year study1 just revealed that most of these brain games don't actually protect against dementia. Only one type does, and it's not what you'd expect. Here's what this means for your brain health and Wordle habit.
The study's surprising findings
The study followed 2,021 adults aged 65 and older for two decades. Researchers tested three types of cognitive training: memory exercises (such as learning word lists), reasoning tasks (such as spotting patterns), and something called "speed training" for a period of five to six weeks. The results? Only speed training made a difference in reducing dementia diagnoses by 25%. Memory and reasoning training showed no significant benefit at all.
About half of the people who didn't do any training eventually developed dementia. So finding something that actually moves the needle is a big deal.
One important note: the benefit only showed up in people who did occasional "booster" sessions after the initial training. Without those refreshers, speed training didn't seem to help much.
What is speed training, exactly?
Speed training isn't about memorizing lists or solving logic puzzles. It focuses on visual processing and divided attention. Essentially, it's how quickly and accurately your brain can take in and respond to visual information.
In the ACTIVE study, participants practiced tasks like identifying objects that flashed briefly in their peripheral vision while simultaneously processing information in the center of their visual field. The training was adaptive, meaning the difficulty automatically increased as participants improved.
This is fundamentally different from crosswords, Sudoku, or trivia games. Those activities rely on knowledge recall and deliberate problem-solving. Speed training, on the other hand, targets the rapid, automatic processing that happens before you even consciously "think" about what you're seeing.
So no, your daily Wordle probably doesn't count, at least not for this type of brain protection.
Why speed training works when other brain exercises don't
The difference comes down to how your brain handles different tasks.
When you do a crossword or try to remember a grocery list, you're using the deliberate, effortful part of your brain, or the kind of thinking where you're consciously working through something. Speed training taps into something different: the behind-the-scenes processing that happens without you trying.
Exercising this automatic kind of thinking with speed training may help keep those pathways strong, especially in ways that other brain games just can't.
However, the refresher sessions really matter. Going back for occasional tune-ups seems to reinforce the benefits and help them stick around longer.
The training protocol: what it actually looks like
The good news? This isn't a huge time commitment:
That's it. A few weeks of training, plus occasional refreshers, for potentially decades of benefit. The catch is that those booster sessions really do seem to matter, because skipping them appeared to erase the advantage.
How to try speed training yourself
The study used a specific computer program, but similar exercises are available through apps like BrainHQ, which offers speed training based on the same ideas.
If you want to give it a shot, look for programs that:
Worth noting: researchers think speed training might work even better when combined with other healthy habits like staying active and eating well. It's one piece of the puzzle, not a magic fix.
The bottom line
Not all brain training is created equal. While your crossword habit is enjoyable (and hey, no judgment—keep doing what you love), this research suggests it probably won't protect against dementia the way speed training might.
The encouraging part? What actually worked wasn't complicated or time-consuming. Just a few weeks of the right kind of training, plus occasional refreshers, could make a real difference over the long haul.
