# Summary

This dataset is a pilot study supported by the Scientific Research Network on
Decision Neuroscience and Aging. The full dataset is described in a published
Scientific Data article (https://doi.org/10.1038/s41597-024-02931-y).

# Abstract

Behavioural and neuroimaging research has shown that older adults are less
sensitive to financial losses compared with younger adults. Yet relatively
less is known about age-related differences in social decisions and social
reward processing. We collected behavioural and functional magnetic resonance
imaging (fMRI) data from 50 participants (younger: N = 26, ages 18–34 years;
older: N = 24, ages 63–80 years) who completed three tasks in the scanner: an
economic trust game as the investor with three partners (computer, stranger,
friend) as the investee; a card-guessing task in which monetary gains and
losses were shared with three partners (computer, stranger, friend); and an
ultimatum game as responder to three anonymous proposers (computer,
age-similar adults, age-dissimilar adults). We also collected B0 field maps and
high-resolution structural images (T1-weighted and T2-weighted images). These
data could be reused to answer questions about moment-to-moment variability in
fMRI signal, representational similarity between tasks, and brain structure.

# Additional Usage Notes

* `sub-2xx` participants do not have imaging data because these individuals
  were the friends of the respective `sub-1xx` participants. For example,
  `sub-204` was the participant outside the scanner playing the role of the
  investee while `sub-104` was the participant inside the scanner playing the
  role of the investor.
* The primary dataset and `participants.tsv` contain **50 imaging participants**.
  Legacy `sub-2xx` records are auxiliary data and remain excluded by
  `.bidsignore`; they are not additional members of the primary sample.
  Their demographics and acquisition documentation are unavailable or
  incomplete. Some source files contain repeated acquisitions or identical
  records under different identifiers. These records require independent
  evaluation before analysis. Supplementary exports and an unresolved-source
  inventory are maintained separately in the code repository, not in the
  primary BIDS release. See `code/FRIEND_BEHAVIOR_EXPORT.md` in that repository.
* Task-linked partner ratings are stored as untimed BIDS behavioral recordings
  under `sub-*/beh/`. The `acq-pre` and `acq-post` entities indicate collection
  timing. When an acquisition was repeated, the final complete attempt is the
  version of record. Missing ratings were not imputed.
* The `derivatives` folder contains fMRIPrep and MRIQC outputs, single-trial
  estimates, and temporal signal-to-noise ratio (tSNR) images.
* All code related to this dataset is available at
  https://github.com/DVS-Lab/srndna-datapaper. This includes source data for
  the scanner tasks and stimulus-presentation scripts.
* For convenience, the `code` and `stimuli` subfolders of the GitHub repository
  have been copied to this dataset.
* Partial-Fourier acquisition was not used. `PartialFourier: 1` is retained;
  no partial-Fourier direction applies. Ontology links describe the associated
  game paradigms, not the separate partner-rating recordings. CogPO IDs are
  omitted where a matching definition has not been verified.

# How to Acknowledge

If using this dataset, please cite the following papers: 1) Fareri et al., 2022,
NeuroImage (https://doi.org/10.1016/j.neuroimage.2022.119267); 2) Smith et al.,
2024, Scientific Data (https://doi.org/10.1038/s41597-024-02931-y); and 3) Fareri
et al., 2026, bioRxiv (https://doi.org/10.1101/2025.08.13.670194).

## Trust run exclusions

Trust run-05 for sub-134 and sub-138 is excluded from this release, together with its run-specific derivatives, because the corresponding behavioral records are unavailable. The previous event tables were empty conversion placeholders. Retained logs uniquely match the run-01 through run-04 trial schedules; the reason for the missing fifth-run records is unknown. The 218 regenerated Trust single-trial outputs already exclude these runs.