In 2016, brain-training company Lumosity paid a $2 million fine to the U.S. Federal Trade Commission for falsely claiming that their games improved memory, prevented Alzheimer's, and boosted academic performance. The science didn't back the claims. So is the entire idea of brain-training games a scam? Not exactly. Here's what actual cognitive research says about which games work — and which don't.

The Lumosity problem

Before we get to what works, let's understand why Lumosity got fined. Their claim was that 10 minutes of their custom games per day would generally improve your cognition. The research showed something more specific: practicing a game makes you better at that game, but those gains usually don't transfer to real-life skills like remembering names, doing taxes, or driving better.

This phenomenon is called far transfer, and it's the holy grail of brain training. Far transfer means the cognitive improvement extends beyond the specific exercise. Most brain-training games show "near transfer" (you get better at similar games) but not "far transfer."

That said — some types of cognitive exercise have been shown, in real peer-reviewed studies, to produce measurable far transfer. Here's what those games look like.

1. Dual N-Back (the only one with strong evidence)

Dual N-Back is a working memory test invented by psychologist Wayne Kirchner in 1958. The basic version: a 3x3 grid lights up squares one at a time, and a voice says letters one at a time. Your job is to press one button if the current square matches the square N steps ago, and another button if the current letter matches the letter N steps ago. N starts at 1 and goes up as you improve.

Why it's interesting: a 2008 study by Susanne Jaeggi and colleagues showed that ~25 minutes per day of Dual N-Back for 19 days produced measurable improvements in fluid intelligence — the IQ-test kind of intelligence that's supposed to be fixed in adults. The results were controversial and not all replications succeeded, but Dual N-Back is the only "brain training" game with peer-reviewed evidence of far transfer.

It's also unbearably boring. Almost nobody sticks with it. So let's look at games that are actually fun.

2. Sudoku (works for working memory and pattern recognition)

Sudoku has multiple peer-reviewed studies showing it improves working memory and logical reasoning, especially in older adults. A 2019 PROTECT study (the largest study of adult cognition ever conducted) found that participants who played number puzzles like Sudoku had cognitive function equivalent to people 8 years younger.

The reason: Sudoku requires you to hold multiple constraints in mind at once. "This row needs a 7, but it can't go in column 4 because of column 4's existing 7, but it can't go in row 7 because..." That kind of multi-constraint reasoning exercises the same brain regions used in real-world planning and decision-making.

Try our Sudoku Mini if you want to start. It uses a smaller 6×6 grid which is friendlier for beginners but still hits the same cognitive systems.

3. Chess (slightly overrated but real)

Chess is the brain-training game with the most cultural reputation. The reputation is partially earned. Studies show chess improves:

  • Spatial reasoning (visualizing the board)
  • Pattern recognition (recognizing tactics like forks and pins)
  • Working memory (holding the board state in mind)
  • Planning ability (thinking 5-10 moves ahead)

However, several recent meta-analyses suggest that the cognitive benefits of chess have been overstated. Chess players are smarter on average, but the causality is murky — smart kids play more chess, not necessarily the other way around.

That said, chess is fun, social, and intellectually engaging. If you want to start with something simpler, Tic Tac Toe uses similar pattern-recognition skills and is free of chess's brutal learning curve. Connect Four is a step up that introduces real planning depth.

4. Tetris (yes, really)

This might surprise you, but Tetris has more research behind it than most "brain training" games. A 2009 study using brain imaging showed that 3 months of Tetris practice increased the thickness of cerebral cortex in regions related to spatial reasoning. The brain literally got physically thicker in the relevant areas.

Other Tetris findings:

  • Playing Tetris within 24 hours after a traumatic event reduces flashback symptoms (the so-called "Tetris effect" — used in some PTSD treatments).
  • Tetris improves spatial visualization, which transfers to math performance in children.
  • Watching someone else play Tetris doesn't produce these effects — you have to actually play.

The reason Tetris works is that it forces continuous mental rotation under time pressure. Your brain has to predict where pieces will land, evaluate alternative orientations, and commit. That's exactly the kind of demanding spatial cognition that builds neural pathways. Try Tetris Blocks.

5. Memory Match / Concentration (good for ages 60+)

The simple game of flipping cards to find pairs has been studied as a treatment for early-stage cognitive decline in older adults. Results are modest but real: regular practice improves visual-spatial memory and attention span in adults over 60.

For younger adults, the effect is much smaller — probably because most under-50 brains don't have much room to improve on this specific skill. But it's still a good game for kids learning concentration. Try Memory Flip.

The 3 brain-training claims that don't hold up

Now for the disappointments. These types of brain training have weak or no evidence of producing real cognitive improvement, despite popular belief.

1. Speed-of-processing games

Games where you have to react quickly to flashing icons (the kind Lumosity sold) make you faster at that specific game. They don't make you a faster thinker overall. The 2016 ACTIVE trial — the largest study of cognitive training ever conducted — showed near-zero far transfer.

2. Word search and crosswords (mixed results)

Crosswords are often recommended for "keeping the brain sharp," but the evidence is weak. They train vocabulary and pattern matching for words, but the transfer to general cognition is small. They're fine entertainment; they're not magical brain medicine.

3. Digital "brain age" tests

Apps that estimate your "brain age" by giving you simple cognitive tasks are essentially gimmicks. The "brain age" number has no medical meaning. The tasks themselves are too short to produce training effects, and the "improvement" you see day to day is mostly practice on the test, not actual cognitive change.

What actually works for cognitive health

Here's the unfun truth: the best things you can do for your brain have nothing to do with games. According to a 2023 review in The Lancet:

  1. Aerobic exercise — by far the largest effect of any single intervention
  2. Sleep (7-9 hours) — sleep deprivation cuts cognitive performance by 30-40%
  3. Social interaction — loneliness in older adults accelerates cognitive decline
  4. Learning new things — a new language, instrument, or hobby
  5. Mediterranean diet — modest but real effect

Brain-training games are way down the list. They're maybe equivalent to "do crosswords daily" — small but positive, especially if you enjoy them.

The bottom line

If you want to play games that actually have some evidence behind them: Sudoku, Tetris, Memory Match, and chess (or its cousins like Connect Four) are your best bets. They're fun, they're free, and the cognitive benefits — while smaller than the marketing suggests — are real.

Play them because you enjoy them, not because you think you're outsmarting Alzheimer's. The first reason is honest. The second one was the basis of a $2 million FTC fine.