Subliminal advertising–hidden messages embedded in ads–is considered a deceptive business practice by the Federal Trade Commission. Yet a legal kind of “subliminal” persuasion happens everyday. Shoppers are regularly encouraged to buy by appeals to their senses or unconscious assumptions. I recently carried out a series of research experiments to uncover the ways advertisers burrow beneath our rational minds to get us to pull out our wallets. Here are five techniques used to mess with our minds that you should know about.