Response orientation modulates pitch–space relationships: the ROMPR effect

Congruency between auditory and visuospatial stimuli has been previously shown to affect responses to multisensory stimulus pairs, and congruency between stimuli and response devices may play a role in response speed and accuracy. Across two experiments, we tested whether the accuracy and speed of pitch judgments were affected by a congruent or incongruent paired visual stimulus, and whether the relationship was modulated by response orientation. In Experiment 1, participants using a vertically (transversely) oriented keyboard demonstrated a large crossmodal vertical effect, but a minimal crossmodal horizontal effect. In contrast, Experiment 2 used a horizontally oriented keyboard, while also examining whether musical training impacts pitch judgments. As in the first experiment, we found an effect of response mapping on pitch judgments; these results suggest that vertical visual stimuli are processed automatically, while the effects of horizontal visual stimuli are decisional and require a compatible response orientation. Based on these findings, we propose an effect we call the ROMPR effect: response orientation modulates pitch–space relationships. Unexpectedly, non-musicians demonstrated significant ROMPR effects while trained musicians did not. We suggest that non-musicians are more likely to use visual information when making spatial location judgments of pitch: unlike musicians, they have not been trained to rely exclusively on auditory information during pitch processing. We also discuss alternative explanations of the data: namely, that there is a need to disambiguate audiovisual congruency from visual–response congruency with modulations of experimental design.