Synesthesia strengthens sound-symbolic cross-modal correspondences

• Type of Material: Article
• Authors: Simon Lacey, Emory University; Margaret Martinez, Emory University; Kelly McCormick, Emory University; Krishnankutty Sathian, Emory University
• Language: English
• Date: 2016-11-01
• Publisher: Wiley: 12 months
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd
• Final Published Version (URL): http://dx.doi.org/10.1111/ejn.13381
• Title of Journal or Parent Work: European Journal of Neuroscience
• ISSN: 0953-816X
• Volume: 44
• Issue: 9
• Start Page: 2716
• End Page: 2721
• Grant/Funding Information: Support to KS from the Veterans Administration is also acknowledged.; This work was supported by NIH grant R01EY025978 to KS and also by a grant to MM from the SIRE program at Emory University.
• Keywords: Neurosciences & Neurology; IMPLICIT ASSOCIATION TEST; INDIVIDUAL-DIFFERENCES; CREATIVITY; COLOR SYNAESTHESIA; EXPERIENCES; SPEEDED CLASSIFICATION; auditory; Science & Technology; VISUAL-IMAGERY; MENTAL-IMAGERY; visual; Life Sciences & Biomedicine; INTEGRATION; implicit association test; STRUCTURAL CONNECTIVITY; Neurosciences
• Research Categories: Health Sciences, Rehabilitation and Therapy; Biology, Neuroscience

Abstract

Synesthesia is a phenomenon in which an experience in one domain is accompanied by an involuntary secondary experience in another, unrelated domain; in classical synesthesia, these associations are arbitrary and idiosyncratic. Cross-modal correspondences refer to universal associations between seemingly unrelated sensory features, e.g., auditory pitch and visual size. Some argue that these phenomena form a continuum, with classical synesthesia being an exaggeration of universal cross-modal correspondences, whereas others contend that the two are quite different, since cross-modal correspondences are non-arbitrary, non-idiosyncratic, and do not involve secondary experiences. Here, we used the implicit association test to compare sy nesthetes’ and non-synesthetes’ sensitivity to cross-modal correspondences. We tested the associations between auditory pitch and visual elevation, auditory pitch and visual size, and sound-symbolic correspondences between auditory pseudowords and visual shapes. Synesthetes were more sensitive than non-synesthetes to cross-modal correspondences involving sound-symbolic, but not low-level sensory, associations. We conclude that synesthesia heightens universally experienced cross-modal correspondences, but only when these involve sound symbolism. This is only partly consistent with the idea of a continuum between synesthesia and cross-modal correspondences, but accords with the idea that synesthesia is a high-level, post-perceptual phenomenon, with spillover of the abilities of synesthetes into domains outside their synesthesias. To our knowledge, this is the first demonstration that synesthetes, relative to non-synesthetes, experience stronger cross-modal correspondences outside their synesthetic domains.