Model-free decision making is prioritized when learning to avoid harming others

Research output: Contribution to journalArticlepeer-review

Authors

Colleges, School and Institutes

Abstract

Moral behavior requires learning how our actions help or harm others. Theoretical accounts of learning propose a key division between "model-free" algorithms that cache outcome values in actions and "model-based" algorithms that map actions to outcomes. Here, we tested the engagement of these mechanisms and their neural basis as participants learned to avoid painful electric shocks for themselves and a stranger. We found that model-free decision making was prioritized when learning to avoid harming others compared to oneself. Model-free prediction errors for others relative to self were tracked in the thalamus/caudate. At the time of choice, neural activity consistent with model-free moral learning was observed in subgenual anterior cingulate cortex (sgACC), and switching after harming others was associated with stronger connectivity between sgACC and dorsolateral prefrontal cortex. Finally, model-free moral learning varied with individual differences in moral judgment. Our findings suggest moral learning favors efficiency over flexibility and is underpinned by specific neural mechanisms.

Details

Original languageEnglish
Pages (from-to)27719-27730
Number of pages12
JournalProceedings of the National Academy of Sciences
Volume117
Issue number44
Publication statusPublished - 14 Oct 2020

Keywords

  • learning, model-free, moral, neuroimaging, prediction error

ASJC Scopus subject areas