Visual Experience influences associations between Pitch and Distance, but not Pitch and Height

Abstract

Background: Cross-modal correspondences are widespread intuitive associations between seemingly unrelated sensory dimensions, such as auditory pitch and spatial elevation. Congruent pairings such as high-pitch with high-elevations influence looking patterns in infants, as well as sensory processing speeds in adults. In previous studies, increased pitch has been put with elevation in the sighted but proximity in the blind, and implicit association tasks show that pitch only corresponds to tactile elevation in the sighted but not the blind. Thus, it is unclear whether pitch-elevation would be present for blind individuals in a purely auditory task. Method: Sighted (N=93), late-blind (N=46), and early-blind (N=50) completed a standard auditory implicit association task between tonal-pitch (low, high) and speech indicating either height (“below”, “above”) or distance (“further”, “closer”). The dependent variable was a D-Score (ranging from +2 to -2) based on reaction time and errors indicating whether there were preferences for congruent or incongruent pairings. Results: ANOVAs revealed that for pitch-height all groups showed a preference for high tonal pitch with “above,” with no significant effects of sightedness, stimuli order, or interaction. However, early-blind subjects showed the strongest preference for congruent pitch-height pairings. For pitch-distance, subjects significantly differed according to both group and order (but not interaction), Bonferroni-corrected post-hoc tests revealed that sighted controls had a significantly stronger pitch-distance association (high with “closer”) than both the early-blind and late-blind subjects and that, when group and stimuli-order are considered, the early-blind showed significantly stronger preferences for whichever pairing was shown first. Discussion: We provide the strongest evidence to date of pitch-height correspondences persisting across groups varying in sightedness. We also provide evidence of sightedness influencing pitch-distance correspondences with the early-blind being uniquely susceptible to ordering effects. This research adds to the growing body of evidence on how visual experience influences multisensory associations.