Mentats

Mentats is an item in Fallout, Fallout 2, and Fallout Tactics: Brotherhood of Steel.

A pillbox of mind-altering chems. Increased memory related functions, and speeds other mental processes. Intelligence and Perception will increase by two points, and Charisma will increase by one point. Affects last for a day. Highly addictive.

Mentats is a reference to Frank Herbert's Dune. They are a profession of highly analytical thinkers with the ability to process information like a computer.