## Background ## This project follows the publication of Woodhead et al (2019): Woodhead ZVJ, Bradshaw AR, Wilson AC, Thompson PA and Bishop DVM (2019). Testing the unitary theory of language lateralization using functional transcranial Doppler sonography in adults. Royal Society Open Science, 6(3), https://doi.org/10.1098/rsos.181801. The original project investigated the covariance structure of lateralisation for different language tasks, in a group of participants who were mostly right handed. We observed that there were a few outlier subjects who had unusual patterns of lateralisation, and those subjects happened to be left handed. In order to further investigate the effect of handedness on patterns of lateralisation, we extended the dataset by recruiting and testing additional participants, most of whom were left handed. This testing was carried out in Bangor University (by Emma Karlsson), whereas the original data was collected in the University of Oxford (by Zoe Woodhead). ## The extended dataset ## The original data collected at Oxford is still available on OSF: https://osf.io/tkpm2/files/ The combined data (from Oxford and Bangor) is available in this OSF repository. Combined together, there is useable data from N=74 subjects (31 left handed and 43 right handed). ## Replicating the analysis All of the scripts and data required to replicate the analysis of the extended dataset are available in this repository. Instructions on how to replicate the analysis can be found in the **Analysis_Readme.pdf** file. For any questions about this project, please contact zoe.woodhead@psy.ox.ac.uk.