Lauren A. Rydel¹ (), Kelly J. Hiersche¹, Zeynep M. Saygin¹; ¹Ohio State University

The visual word form area (VWFA) is a region within the ventral temporal cortex (VTC) that shows category selectivity (i.e. univariate selectivity) for visual words and letter strings but only after an individual learns how to read. What precedes this response? Previous work demonstrates that children lacking category selectivity for face, bodies, or scenes in VTC display mature representational patterns (i.e. multivariate selectivity), suggesting distributed patterns of responses may scaffold later category selectivity. Does the VWFA also emerge from initially multivariate representations in pre-readers? Given that the VWFA is a ‘bridge’ between language and vision, does it show linguistic multivariate representation? In this study, we investigate whether pre-reading children exhibit a multivariate response to written words or auditory language across the VTC. Next, we examine if the voxels that decode written words can also distinguish between auditory language and control conditions. Children (N=74): 35 pre-readers ages 2-6 and 39 readers ages 4-13, completed two runs each of a high-level visual fMRI localizer (word, scrambled word, object, and face conditions), and auditory language task (linguistically meaningful sentences, matched nonword sentences, and texturized sound conditions). Multi-voxel pattern analysis (MVPA) identified voxels within the VTC with higher within-condition correlations than between conditions. Despite lacking a univariate word response, pre-readers show the start of a multivariate pattern for decoding words within the VWFA, similar to readers (who have a multivariate and univariate word response). Further, these multivariate word voxels (but not other voxels) also show a strong within-condition correlation for auditory sentences, but not auditory control conditions, in both pre-readers and readers, suggesting initial distributed linguistic representations in a visual area. Overall, distributed responses may indeed scaffold later-developing category selectivity even for new knowledge domains. Ongoing work investigates the shift to categorical selectivity in longitudinal development, and contribution of connectivity and other anatomical constraints.

Acknowledgements: NIH R01 HD110401-01 and Alfred P Sloan: FG-2018-10994 (to Z.M.S.); NSF GRFP: DGE-1343012 (to K.J.H.)