College students with depression symptom are more sensitive to task difficulty in reinforcement learning

Area of Science:

• Neuroscience
• Psychology
• Cognitive Science

Background:

• Depression is linked to impaired reward processing and altered motivation in reinforcement learning.
• Understanding how task difficulty influences this process in students with depression is crucial.

Purpose of the Study:

• To investigate the impact of varying task difficulties on reinforcement learning in college students with and without depression symptoms.
• To explore the relationship between electrophysiological responses and reward learning behaviors across different difficulty levels.

Main Methods:

• A probabilistic reward learning task with low, medium, and high difficulty levels was administered to two groups: students with depression symptoms (n=20) and without (n=26).
• Response bias and reward discriminability were analyzed. Electrophysiological responses to reward and loss feedback were recorded during a separate gambling task.

Main Results:

• Students with depression showed greater initial response bias to rewards, which decreased more rapidly with increasing task difficulty compared to the control group.
• The Feedback-related negativity (FRN) and theta oscillations predicted response bias changes in easy tasks, while FRN, theta, and delta oscillations predicted changes in medium and high-difficulty tasks.

Conclusions:

• College students with depression symptoms demonstrate heightened sensitivity to task difficulty during reinforcement learning.
• Electrophysiological markers like FRN and theta/delta oscillations are predictive of reward learning behaviors, particularly under varying task difficulties.