PT  - JOURNAL ARTICLE
AU  - Jacqueline Katharina Meier
AU  - Bernhard P. Staresina
AU  - Lars Schwabe
TI  - Stress diminishes outcome but enhances response representations during instrumental learning
AID  - 10.1101/2021.02.12.430935
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.02.12.430935
4099  - http://biorxiv.org/content/early/2021/02/14/2021.02.12.430935.short
4100  - http://biorxiv.org/content/early/2021/02/14/2021.02.12.430935.full
AB  - Stress may shift behavioural control from a goal-directed system that encodes action-outcome relationships to a habit system that learns stimulus-response associations. Although this shift to habits is highly relevant for stress-related psychopathologies, limitations of existing behavioural paradigms hindered previous research to answer the fundamental question of whether the stress-induced bias to habits is due to impaired goal-directed or enhanced habitual processing (or both). Here, we leveraged EEG-based multivariate pattern analysis to decode neural outcome representations, crucial for goal-directed control, and response representations, essential for habitual responding, during instrumental learning. We show that stress reduces outcome representations but enhances response representations, both of which were directly associated with a behavioural index of habitual responding. Further, changes in outcome and response representations were uncorrelated, suggesting that these may reflect distinct processes. Our findings indicate that habit behaviour under stress is the result of both enhanced habitual and diminished goal-directed processing.Competing Interest StatementThe authors have declared no competing interest.