Publisher Summary The difference in reaction time between the incompatible and the compatible conditions reflects the degree to which the flankers influence reaction time to the target—that is, the flanker compatibility effect. The chapter discusses the asymmetries in the flanker compatibility effect (FCE). Even though the task explicitly requires the identification of the central target letter in a string of three letters and the ignorance of the flanking letters, the FCE indicates that the flanking letters cannot be ignored; rather they are also identified and influence reactions time (RT) to the central target letter. The chapter examines experimental conditions in which the stimulus display contains one response-incompatible flanker and one response-neutral flanker—that is, displays in which there is no response assigned to one of the flanker letters. To determine the generality of these results and the degree to which they are consistent with other researchers, the chapter utilizes different letters to test for asymmetries in the FCE.