What is a mentalist?

Yes, mentalists are a sub-set of stage magicians who use various types of psychological techniques and gimmicks in order to perform tricks on stage. All stage magic has psychological elements to it. The type of tricks employed by most famous TV magicians makes use of manipulating objects or part of the scenery. Mentalism usually requires that the performer use psychological cues in order to fool the audience into, for example, thinking that the performer has some psychic power to predict what you are thinking.