ECoG data: ECoG data have been divided into specific trials, and all data were preprocessed by the steps described in the manuscript, and the electrodes with significant activities have been selected. In the ECoGdata folder, the file start with "Ji" means the data were collected from marmoset Ji, "Nr" mean marmoset "Na". Ji_XXtask_standard_trials: xx|xx trials Ji_XXtask_deviant_trials: xY|xx trials Ji_XXtask_omission_trials: x_|xx trials Ji_XYtask_deviant_trials: xx|xY trials Ji_XYtask_standard_trials: xY|xY trials Ji_XYtask_omission_trials: x_|xY trials Ji_omission_block: xxxx trials In the ***_trials.mat files, the sturct parameters in the object "dataFreqMerge" and "dataRareMerge" have the same meaning, except dataFreqmerge are all trials extracted from satandard trials in each task, and dataRareMerge are all trials extracted from deviant trials in each task. The details of struct parameter: label: the number of electrodes trial: the signals of each trial, with the format: electrode * trial time: the timepoint of each trial fsample: sampling rate cfg: the processing parameters derived from fieldtrip toolbox. The Ji_layout.mat and Nr_layout.mat are the electrode layout files for marmoset Ji and Nr, which canbe used directly by fieldtrip toolbox. For details, you can also read the inforamtion from fieldtrip toolbox. fMRI data: fMRI data are the images for group results and individual marmosets. The raw data or preprocessed data are too large to be uploaded. The interested party could contact the corresponding author to request for the data. In the fMRI/groupResults folder, first_level_activity: contrast image of first-level novelty second_level_activity: contrast image of second-level novelty first_and_second_level_activity: contrast image of both first- and second-level novelty xxtask_omission: contrast image of x_|xx - xx|xx xYtask_omission: contrast image of x_|xY - xY|xY xYtaskOmission_minus_xxtaskOmission: contrast image of x_|xY - x_|xx The files in the fMRI/individualmonkey_results folder are with the same rules as in groupResults folder, but from marmoset 1, 2, 3.