Data presented in the manuscript “Distinct early and late neural mechanisms regulate feature-specific sensory adaptation in the human visual system”, published in PNAS (2023). All data has been preprocessed and cleaned. Behavioural data comprises a single excel document, with 3 sheets corresponding to the spatial frequency detection task in the (1) pre-adaptation and (2) post-adaptation phases, and (3) the orientation reproduction task in the post-adaptation phase. For the detection task, responses are provided in binary, where 1 indicates that the participant correctly identified the number of targets in a particular trial and 0 indicates they responded incorrectly. For the reproduction task, the values represent the circular distance between the participants’ response and that of the test grating. Responses are normalized such that a positive value indicates a bias away from the adaptor and a negative value indicates a bias towards the adaptor. EEG data comprise 36 MATLAB .mat files; one for each participant. Each file contains the epoched EEG responses, the orientation of the grating presented, and the adapting orientation.