AUTHOR=Umemura Hiroyuki TITLE=Independent effects of 2-D and 3-D locations of stimuli in a 3-D display on response speed in a Simon task JOURNAL=Frontiers in Psychology VOLUME=Volume 6 - 2015 YEAR=2015 URL=https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2015.01302 DOI=10.3389/fpsyg.2015.01302 ISSN=1664-1078 ABSTRACT=The Simon Effect is a phenomenon in which reaction times are usually faster when the stimulus location and the response correspond, even if the stimulus location is irrelevant to the task. Recent studies have demonstrated the Simon effect in a three-dimensional (3-D) display. The present study examined whether two-dimensional (2-D) and 3-D locations simultaneously affected the Simon effect for the stimuli in which a target stimulus and fixation were located on the same plane (ground or ceiling) at different 3-D depths, and the perspective effect produced difference in the 2-D vertical location of the target stimulus relative to the fixation. The presence of a ground and ceiling plane was controlled to examine the contextual effect of background. The results showed that the 2-D vertical location and 3-D depth simultaneously affected the speed of responses, and they showed no interaction. The presence of the background did not affect the magnitude of either the 2-D or the 3-D Simon effect. These results suggest that 2-D vertical location and 3-D depth are coded simultaneously and independently, and both of them affect the response selection in which 2-D and 3-D representations overlap.