**General** These are the data and stimulus code from the following publication: Rademaker, R.L., van de Ven, V.G., Tong, F., & Sack, A.S. (2017). The impact of early visual cortex transcranial magnetic stimulation on visual working memory precision and guess rate. PLoS ONE 12(4): e0175230. **Data** Behavioral and Neuroimaging data (used during TMS) are in separate folders. Each subject has behavioral data of all sessions combined in a single .mat file. The Neuronavigation folder has a "readme" file with more details concerning its contents. Data have been anonimized (subject initials were used as identifiers during data acquisition). **Stimulus Code** TMS_WM_Setsize4.m is the original experimental code (using Matlab & the Psychtoolbox) used to run the experiment at Maastricht University in the Netherlands. The monitors was gamma corrected. Because gamma correction differs from monitor to monitor, we have not supplied the gamma lookup table (run this code after commenting out the lines where this correction is applied – or replace it with your own correction). The script also relies on a number of helper functions (in the folder "Helper Functions"). To successfully run the script you will need to have your helper functions in the path, and you need to create a folder called "Data" in the same directory from which you will run the stimulus script. **Bug Report** The Experiment code has a bug, which is described in detail in the folder "bug report". If you want to actually use the experiment code, it would be advisable to fix this bug in the original code, rather than fix it post-hoc.