The brain-training controversy
Commercial brain-training apps exploded in the 2010s, promising sharper memory and higher IQ. A 2016 consensus statement signed by more than 70 cognitive scientists pushed back: most apps make players better at the trained tasks, but the gains rarely transfer to real-world cognition.
That does not mean cognitive performance is fixed. It means the path to meaningful improvement looks different from playing matching games on a phone.
What has strong evidence
Aerobic exercise has the strongest, most replicated effect on cognition across the lifespan. Studies show that 150 minutes per week of moderate cardiovascular activity improves processing speed, executive function, and even hippocampal volume in older adults.
Sleep is the second pillar. Memory consolidation happens during deep and REM sleep; chronic restriction below seven hours measurably degrades attention, working memory, and decision-making.
Learning genuinely new and difficult skills — a language, an instrument, a complex sport — produces lasting structural changes in the brain. The key word is 'difficult': comfortable repetition does not drive plasticity.
What has weaker evidence
Most over-the-counter 'nootropic' supplements show no benefit in well-controlled trials. Caffeine and L-theanine reliably improve short-term alertness; almost nothing else does.
Listening to classical music does not raise your IQ. The original 'Mozart effect' study found a small, temporary boost in spatial reasoning after listening — limited to that one task, limited to about fifteen minutes.
A practical weekly plan
Three sessions of 40 minutes of brisk aerobic exercise; seven to eight hours of sleep on a regular schedule; thirty minutes a day learning something genuinely hard; and a balanced diet with adequate omega-3s and protein. None of this is glamorous, and all of it is supported by decades of research.