Encoding Numbers When Numbers Rotate to the Left or Right Space: Evidence from the Spatial-Numerical Association of Re-sponse Codes (SNARC) Effect

Although previous studies have investigated the relationship between the SNARC effect and the Simon effect, the results of these previous studies are inconsistent. In addition, when spatial cues are not overly prominent or salient, how spatial cues influence the SNARC effect is still unknown. The present study rotated Arabic numbers 45 degrees to the left or right and randomly and centrally presented these rotated numbers for participants to investigate the above questions in an orientation task (experiment 1), parity task (experiment 2), and magnitude task (experiment 3). The results revealed that 1) the SNARC effect was absent, but a Simon-like effect was present in the orientation classification task. 2) The SNARC effect was present only in the orientation-response consistent condition but was absent in the orientation-response inconsistent condition in the numerical parity task (experiment 2) and numerical magnitude classification task (experiment 3). From these results, it can be concluded that 1) rotating numbers to the left or right can substantially influence the SNARC effect and that 2) how rotated orientation influences the SNARC effect is moderated by the task performed when numbers are rotated to the left or right. These results imply that even when spatial cues are not overly prominent or salient, numerical spatial cues can also impede the role of numerical visuospatial coding and numerical verbal-spatial coding in individual responses.