This site contains the pupil data from the publication Cortical State Fluctuations during Sensory Decision Making, by Jacobs et al in Current Biology.This data is from the behavioural tasks described in the publication. The data consist of the results from a custom pupil size extraction algorithm, and requires further preprocessing. The code to perform the preprocessing is available with the companion code (https://github.com/eakjacobs/Jacobs_et_al_CurrentBiology). The raw data can also be shared upon request (they are not uploaded here because of the large size of the videos); please get in touch via email. The timestamps associated with the results here are also not yet aligned to the behavioural data; the companion code takes care of this as well.The data is organised by experimental subject; most subjects were recorded from on multiple days, which form subfolders within the subject folder. Within a day, there may have been several experiments, which are again contained in subfolders within the day folder. The companion code expects this data organisation.If there are any problems or questions, please raise an issue on GitHub.Please follow this link for more information: https://doi.org/10.6084/m9.figshare.13084805The research article can be found (freely available) at: https://www.cell.com/current-biology/fulltext/S0960-9822(20)31437-8