1 2 3 4 5 6 7 Colors in mind : A novel paradigm to investigate pure color imagery 8

27 Mental color imagery abilities are commonly measured using paradigms that involve naming, 28 judging or comparing the colors of visual mental images of well-known objects (e.g., “is a 29 sunflower darker yellow than a lemon”?). Although this approach is widely used in patient 30 studies, differences in the ability to perform such color comparisons might simply reflect 31 participants’ general knowledge of object colors rather than their ability to generate accurate 32 visual mental images of the colors of the objects. The aim of the present study was to design a 33 new color imagery paradigm. Participants were asked to visualize a color for 3 s and then to 34 determine a visually presented color by pressing one of six keys. We reasoned that 35 participants would react faster when the imagined and perceived colors were congruent than 36 when they were incongruent. In Experiment 1, participants were slower in incongruent than 37 congruent trials but only when they were instructed to visualize the colors. The results in 38 Experiment 2 demonstrate that the congruency effect reported in Experiment 1 cannot be 39 attributed to verbalization of the color that had to be visualized. Finally, in Experiment 3, the 40 congruency effect evoked by mental imagery correlated with performance in a perceptual 41 version of the task. We discuss these findings with respect to the mechanisms that underlie 42 mental imagery and patients suffering from color imagery deficits. 43