Stress effects on learning and feedback-related neural activity depend on feedback delay

Area of Science:

• Neuroscience
• Cognitive Psychology
• Stress Research

Background:

• Neural mechanisms of learning vary with feedback timing, implicating the dopamine system, dorsal striatum, and anterior cingulate cortex (ACC) for immediate feedback.
• Stress is known to influence striatum-dependent learning, suggesting a potential differential effect on learning from immediate versus delayed feedback.

Purpose of the Study:

• To investigate how acute stress affects learning and neural processing of immediate and delayed feedback.
• To explore the role of cortisol in mediating stress-induced alterations in feedback processing.

Main Methods:

• Participants underwent either a stress induction (socially evaluated cold pressor test) or a control condition.
• Reward learning task with immediate (500 ms) and delayed (6,500 ms) feedback presentation.
• Electroencephalography (EEG) recorded brain activity; cortisol levels were measured.

Main Results:

• Stress enhanced learning accuracy for delayed feedback relative to immediate feedback.
• Stress reduced the valence effect of feedback-related negativity (FRN) and P300, particularly for delayed feedback.
• Frontal theta power, associated with negative feedback, was reduced under stress and showed decreased correlation with accuracy.
• Cortisol increases were associated with observed EEG changes in feedback processing.

Conclusions:

• Stress differentially affects learning from immediate and delayed feedback, potentially by enhancing salience processing and reducing cognitive control.
• Cortisol plays a role in mediating stress-related changes in neural feedback processing, distinct from the typical dopamine system and ACC involvement.