Philosophical transactions of the Royal Society of London. Series B, Biological sciences
December 9, 2019
David J Schwartzman, Daniel Bor, Nicolas Rothen et al.
7 citations
Synaesthesia, where specific stimuli automatically trigger additional perceptual experiences, offers insight into conscious perception. While traditionally considered congenital, growing evidence shows that synaesthesia-like experiences can be induced in non-synaesthetes, even in adulthood. This review examines various methods for artificially inducing such experiences and compares them to natural synaesthesia's hallmarks: consistency, automaticity, and lack of 'perceptual presence'. The authors conclude that many aspects of synaesthesia can be induced, suggesting developmental and learning components in its acquisition and extending evidence of perceptual plasticity in adults.
bioRxiv Preprint Server
August 3, 2020
David. J. Schwartzman, Ales Oblak, Nicolas Rothen et al.
4 citations
preprint
Grapheme-colour synaesthesia (GCS) involves automatic, consistent colour experiences triggered by letters or numbers. Two recent studies showed that extensive associative training can produce behavioural, neurophysiological, and phenomenological markers of synaesthesia in non-synaesthetes, but they did not deeply compare the induced experiences to natural synaesthesia. This study analyzed interview transcripts from participants who underwent such training and from natural synaesthetes. Both groups shared several experiential categories, including stability, location, shape, relative strength, and automaticity of colour experience. However, automaticity differed significantly: natural synaesthetes mostly reported automatic experiences, while induced synaesthesia-like experiences were mostly described as wilful. Additional categories emerged only in natural synaesthetes, highlighting heterogeneity. The results indicate that intensive training can alter conscious perception, producing phenomenology substantially resembling natural synaesthesia.