SPSS raw data and SPSS script for analysis reported in Bishop et al (2014). Matlab files for extracting laterality index and related variables from raw Doppler files. N.B. raw files are included in .mat format and can be read from Matlab using load command. **Update 16 Feb 2016** An error was found in the program that computed laterality indices from the functional transcranial Doppler ultrasound. The laterality index should have been based on all administered trials. To estimate the reliability of this index, we also computed the same index using just the odd or even trials. A scripting error meant that the laterality index based on just the even trials had overwritten the index based on all trials. Thus the results originally reported were based on correct data, but used a laterality index based on only half the available trials. The corrected program and analysis have been corrected and are provided under OSFstorage. The original versions, which include the error, are under Original files. A corrected version of the manuscript will be posted on the PeerJ site shortly.