Bonte, M. 1 , Correia, J. 1 , Keetels, M. 2 , Vroomen, J. . 2 & Formisano, E. 1
1 Dept. of Cognitive Neuroscience, Faculty of Psychology & Neuroscience, Maastricht University; Maastricht Brain Imaging Center, The Netherlands
2 Dept. of Cognitive Neuroscience and Neuropsychology, Tilburg University, Tilburg, The Netherlands
Efficient neural associations between written and spoken language representations are important for fluent reading skills and may be compromised in dyslexic readers. Experimental paradigms used to study these associations typically require stimulus congruency manipulations or higher-order tasks. Here we use a newly-developed text-based recalibration paradigm that takes advantage of the finding that visual presentation of text induces an illusory shift in the perception of ambiguous speech. We have recently demonstrated this effect at the behavioral level using speech sound /a?a/, where ? is an ambiguous phoneme midway between /b/ and /d/. To investigate the neural effects of text-based recalibration we analyzed functional MRI data of 15 typically reading adults using univariate and multivariate decoding techniques. Ambiguous speech sounds evoked BOLD responses across the superior temporal cortex extending towards the posterior middle temporal cortex, as well as in frontal and parietal regions. Most interestingly, fMRI decoding results indicate that it is possible to extract the text-induced perceptual interpretation of ambiguous speech sounds from brain activity patterns in the posterior superior temporal cortex. The text-based recalibration paradigm thus provides a promising tool to study neural mechanisms underlying (lack of) audiovisual plasticity during typical and dyslexic reading development.