Correction to: Nature Methods https://doi.org/10.1038/s41592-018-0224-7, published online 30 November 2018

In the version of this Comment originally published, the authors omitted a funding source. Grant 5 P50 DA039841 (to E.J.C.) from the US National Institute on Drug Abuse has been added to the Acknowledgements in the HTML and PDF versions of the paper.