Habitual behavior after stress: alterations in outcome representations?
Final Report Abstract
Instrumental learning can be controlled by a goal-directed and by a habitual process. Previous findings showed that acute stress may induce a shift from goal-directed to habitual processes. Although this stress-induced shift to habits may be relevant for clinical settings, it was unknown when this shift occurs and whether it is due to impaired goal-directed or enhanced habitual processing. To address these questions, this project combined multivariate decoding analyses with electroencephalography (EEG) to assess the neural representation of action outcomes, critical for goal-directed action, and of response options across an extended instrumental learning session. More specifically, participants underwent a stress or control manipulation before they completed a learning task that could be solved by goal-directed action-outcome or habitual stimulus-response learning. Outcome devaluations shortly after training started, after half of the task and at the end of the task revealed the mode of instrumental control. Our behavioral data showed that while both groups performed goal-directed at the beginning of the task and after moderate training, stress participants responded significantly more often to devalued options at the end of the task, suggesting a training-dependent shift to habitual responding after stress. The EEG-based decoding analysis revealed that stress reduced outcome representations but enhanced response representations, again after extended training. Both representational changes were directly associated with a behavioral index of habitual responding. Furthermore, changes in outcome and response representations were uncorrelated, suggesting that these may reflect distinct processes. Together, our data indicate that habitual behavior under stress may be the result of both enhanced stimulus-response processing and diminished outcome processing. Beyond their theoretical relevance, these findings may have implications for stress-related disorders characterized by aberrant habitual behavior, such as addiction or obsessive-compulsive disorder.
Publications
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Stress diminishes outcome but enhances response representations during instrumental learning. Cold Spring Harbor Laboratory.
Meier, Jacqueline Katharina; Staresina, Bernhard P. & Schwabe, Lars
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Stress diminishes outcome but enhances response representations during instrumental learning. eLife, 11.
Meier, Jacqueline Katharina; Staresina, Bernhard P. & Schwabe, Lars
