boost (one's) brainpower

Translations
увеличить (свой) умственный потенциал
They are trying to boost their brainpower with puzzles.
Они пытаются увеличить свой умственный потенциал с помощью головоломок.
Definitions
To enhance or improve cognitive abilities, mental capacity, or overall brain function through various means such as learning, mental exercises, nutrition, or lifestyle changes.