 The concept of mental imagery was first consistently used in the then very new discipline of empirical psychology at the end of the 19th century. At that time, psychologists like Francis Galton, Wilhelm Wundt or Edward Titchener (Galton 1880, Wundt 1912, Titchener 1909) thought of mental imagery as a mental phenomenon characterized by its phenomenology – a quasi-perceptual episode with a certain specific phenomenal feel. This stance lead to serious suspicion, and often the outright rejection, of this concept in the following decades when behaviorism dominated the psychological discourse (Kulpe 1895, Ryle 1949, Dennett 1969). It was not until the 1970s that mental imagery was again considered to be a respectable concept to study in the empirical sciences of the mind.