De Rosa, M., Vignali, L., D'Urso, A., Ktori, M., Bottini, R. & Crepaldi, D. (2023). Selective Neural Entrainment Reveals Hierarchical Tuning to Linguistic Regularities [preprint]]
Reading is both a visual and a linguistic task, and as such it relies on both general-purpose, visual mechanisms and more abstract, meaning-oriented processes. Disentangling the roles of these resources is of paramount importance in reading research. The present study capitalizes on the coupling of Fast Periodic Visual Stimulation (FPVS; Rossion, 2014) and MEG recordings to address this issue, and investigate the role of different kinds of visual and linguistic units in the visual word identification system. We compared strings of pseudo-characters (BACS; Vidal et al., XXXX); strings of consonants (e.g,. sfcl); readable, but unattested strings (e.g., amsi); frequent, but non-meaningful chunks (e.g., idge); suffixes (e.g., ment); and words (e.g., vibe); and looked for discrimination responses with a particular focus on the ventral, occipito-temporal regions. The results revealed sensitivity to alphabetic, readable, familiar and lexical stimuli. Interestingly, there was no discrimination between suffixes and equally frequent, but meaningless endings, thus highlighting a lack of sensitivity to semantics. Taken together, the data suggest that the visual word identification system, at least in its early stages, is particularly tuned to form-based regularities, perhaps reflecting its reliance on general-purpose, statistical learning mechanisms that are a core feature of the visual system as implemented in the ventral stream.
Files SL26_N_ contain the different steps for processing the data. SL_26_combineplanarAVG and SSEP_X contain functions needed in some of the processing steps. The analyses rely on the usage of FieldTrip (Robert Oostenveld, Pascal Fries, Eric Maris, and Jan-Mathijs Schoffelen. FieldTrip: Open Source Software for Advanced Analysis of MEG, EEG, and Invasive Electrophysiological Data. Computational Intelligence and Neuroscience, 2011; 2011:156869.)