Hearing what you see: Distinct excitatory and disinhibitory mechanisms contribute to visually-evoked auditory sensations.

Autor: Freeman ED; Cognitive Neuroscience Research Unit, Department of Psychology, City, University of London, Northampton Square, London, EC1V 0HB, UK. Electronic address: elliot.freeman@city.ac.uk.
Jazyk: angličtina
Zdroj: Cortex; a journal devoted to the study of the nervous system and behavior [Cortex] 2020 Oct; Vol. 131, pp. 66-78. Date of Electronic Publication: 2020 Jul 15.
DOI: 10.1016/j.cortex.2020.06.014
Abstrakt: Visual motion or flashing lights can evoke auditory sensations in some people. This large-scale internet study aimed to validate a combined subjective/objective test of the genuineness of this putative form of synaesthesia (visually-evoked auditory response, vEAR). Correlations were measured between each individual's ratings of the vividness of auditory sensations evoked by a series of looping videos, and measurement of the videos' physical low-level motion energy, calculated using Adelson and Bergen's (1985) computational model of low-level visual motion processing. The strength of this association for each individual provided a test of how strongly subjective vEAR was driven by objective motion energy ('ME-sensitivity'). A second aim was to infer whether vEAR depends on cortical excitation and/or disinhibition of early visual and/or auditory brain areas. To achieve this, correlations were measured between the above vEAR measures and visual contrast surround-suppression, which is thought to index lateral inhibition in the early visual system. As predicted by a disinhibition account of vEAR, video ratings were overall higher in individuals showing weaker surround-suppression. Interestingly, surround-suppression and ME-sensitivity did not correlate. Additionally, both surround-suppression and ME-sensitivity each independently predicted different clusters of trait measures selected for their possible association with cortical excitability and/or disinhibition: Surround-suppression was associated with vEAR self-ratings and auditory-evoked visual phosphenes, while ME-sensitivity was independently associated with ratings of other traits including susceptibility to migraine and pattern glare. Altogether, these results suggest there are two independent mechanisms underlying vEAR and its associated traits, based putatively on cortical disinhibition versus excitability.
Competing Interests: Declaration of Competing Interest There are no conflicts of interest.
(Copyright © 2020 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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