# Overview Hemispheric structural asymmetries are widely thought to reflect hemispheric organization for language that confers behavioral advantage and facilitate the development of normal reading skills, but could also constrain expression within the normal range according to a canalization hypothesis. A topological data analysis approach was used with structural asymmetry data from T1-weighted images to test the hypotheses that increased leftward structural asymmetries explain superior phonological decoding ability or constrain this ability within the normal range. Significant results, based on replicated effects across two large samples, demonstrated support for both hypotheses; with evidence for the cerebral asymmetry hypothesis when combining asymmetry data across the left hemisphere and evidence for canalization when examining specific regions of interest. This repository documents the metholodgy and data processing steps involved in the analysis. Information are organized in the following subsections: - Raw data and study description, [link](https://osf.io/75g9d/wiki/Raw%20data%20and%20study%20description/) - Persistence diagrams and persistence pairs computation, [link](https://osf.io/75g9d/wiki/Persistence%20diagrams%20and%20persistence%20pairs/) - Data analysis in R, [link](https://osf.io/75g9d/wiki/Data%20analysis/)