Permission to use open fmri data

hello, do we need to ask permission to use the open fmri data?
if yes, how to do it?

many thanks.

It depends on the dataset.

For you do not need any permission to download the data (but you should be sure to acknowledge the authors of the dataset in your papers!).

For larger multisite datasets like the Human Connectome Project (HCP) or Healthy Brain Network (HBN), you usually need to sign a data use agreement (DUA) to access phenotypic data, while imaging data may or may not require a DUA. Each project has a different way of doing a DUA, but you should be able to find directions on the project websites. For example, HBN DUA, and HCP DUA.

Hope this helps,