When you use a metonymy to say “I’ve got a new set of wheels,” why do you refer to a car by means of the wheels rather any other part? Most cognitive linguist would agree that we prefer to talk about parts that are somehow salient, yet the seemingly simple notion of salience is entangled in a number of intricate problems related to how we understand and talk about the surrounding reality. Adopting the theoretic framework of Ronald Langacker’s Cognitive Grammar, this volume studies deep and general cognitive factors governing salience effects that influence the ways we use conceptual metonymies in phonic and sign languages.