# Dataset from: ### "Increasing stimulus similarity drives nonmonotonic representational change in hippocampus" >Wammes, J. D., Norman, K. A., & Turk-Browne, N. B. (2021). Increasing stimulus similarity drives nonmonotonic representational change in hippocampus. *eLife*. This repository contains data used for the analyses of this manuscript. There are 41 zip files, one for each subject, this README file, a demographics.csv file, and three additional zip files. To analyze this data, you should refer to [this github repository](https://github.com/thelamplab/differint). The repository assumes that the 41 subjects' zip files, as well as fieldmaps.zip, design.zip and sorting_data.zip are housed in the folder `differint/data/zip` To start, you can either run `. arrange_all.sh` to put all participants in the correct folder organization for the code, or run them one by one by running `. arrange_data sub-${n}` for each of the 41 participant numbers. From there, the code in the github repository will walk you through preprocessing and analyzing the data. The scan sequences are as follows: 1. **T1 MPRAGE:** TR = 2300 ms, TE = 2.27 ms, flip angle = 8 degrees, matrix = 256 x 256, slices = 208, resolution = 1 mm isotropic, GRAPPA acceleration factor=3 2. **T2 TSE:** TR = 11390 ms, TE = 90 ms, flip angle = 150 degrees, matrix = 384 x 384, slices = 54, perpindicular to hippocampal long axis, resolution = 0.44 x 0.44 x 1.5 mm 3. **EPI:** TR = 1.5 s, TE = 32.6 ms, flip angle = 71 degrees, matrix = 128 x 128, slices = 90, resolution = 1.5 mm isotropic ## File/directory descriptions: #### **demographics.csv**: Summary table of the relevant participant information. The description of the column labels is below: - `ID`: The subject ID number - arbitrary and not in temporal order. - `Age`: Self-identified age (in years) of the participant - `Gender`: Self-identified gender of the participant - `StatLearning`: Where or not they were eligible to be included in the statistical learning analyses (1 for yes, 0 for no) #### **sub-${n}.zip** ***(where ${n} ranges from 01-41 inclusive)*** Zip files containing the anatomical and functional data for a given participant: * `anat`: a folder containing the T1 and T2 anatomical scans for a given participant * `sub-${n}_T1w.nii.gz`: The T1 MPRAGE scan for a given participant * `sub-${n}_T1w.nii.gz`: The T2 TSE scan for a given participant * `func`: A folder containing the functional data and corresponding event files for a given participant * `sub-${n}_task-${task}_run-${r}_bold.nii.gz`: The EPI data for a given functional run, with naming convention as follows: * **${n}**: subject ID number (01-41) * **{task}**: the task the participant was running (random = randomly shuffled runs; pair = statistical learning runs) * **${r}**: run number (01-08). ***Note.*** *tasks are numbered independently. In a standard participant, they completed a random run, then six pair runs, then a final random run. This would be named (in order) * * sub-00_task-random_run-01_bold.nii.gz * sub-00_task-pair_run-01_bold.nii.gz * sub-00_task-pair_run-02_bold.nii.gz * sub-00_task-pair_run-03_bold.nii.gz * sub-00_task-pair_run-04_bold.nii.gz * sub-00_task-pair_run-05_bold.nii.gz * sub-00_task-pair_run-06_bold.nii.gz * sub-00_task-random_run-02_bold.nii.gz * `sub-${n}_task-${task}_run-${r}_events.tsv`: A summary table for the functional run corresponding to the naming convention. The description of the column labels is below. ***Note.*** Naming convention identical to the above functional runs. * `onset`: The time point (in s) when an image onset happened * `duration`: The amount of time (in s) that an image was on screen * `trial_type`: The name of the image that appeared on screen * `c${chan1}-${chan2}_${sim}${pairmate}` - naming convention is as follows: * **${chan1}/${chan2}**: the high-level feature channels that initialized this image pair. * **${sim}**: the level of visual similarity ([0, 14, 29, 43, 57, 71, 86, 100]). * **${pairmate}**: whether it is the A (first) or B (second) image in a pair. #### **fieldmaps.zip** A zip file containing field maps for all participants where they are available. * `sub-${n}_APmap.nii.gz`: Anterior to posterior field map * `sub-${n}_PAmap.nii.gz`: Anterior to posterior field map #### **design.zip** A zip file containing regressor files for all participants and runs, which can be input to FSL's FEAT function. * `sub-${n}_task-${task}_run-${r}_c${chan1}-${chan2}_${sim}${pairmate}.txt`: A regressor file for a single image in a given run. ***Note.*** Naming convention identical to the above functional runs, event files, and image names. #### **sorting_data.zip** A zip file containing data from the behavioral sorting experiment used to validate experimental stimuli. Contains three batches, each file named: * `Batch${batch}.txt`, where ${batch} is 1, 2 or 3.