Is the encoding of Reward Prediction Error reliable during development?

Area of Science:

• Neuroscience
• Developmental Psychology
• Computational Psychiatry

Background:

• Reward prediction errors (RPEs) are crucial for reinforcement learning, development, and understanding psychopathology.
• fMRI can estimate RPE encoding in humans, but its test-retest reliability over time is not well understood.
• Youth experience significant developmental changes in reward processing.

Purpose of the Study:

• To investigate the 3-month and 3-year test-retest reliability of RPE encoding in youth.
• To examine the differential encoding of positive and negative RPEs in brain regions.
• To identify reliable neural markers for RPEs in longitudinal developmental studies.

Main Methods:

• Examined fMRI data from youth (mean age 10.6 years) across two time intervals (3 months and 3 years).
• Assessed the reliability of RPE signal encoding in various brain regions.
• Analyzed valence-dependent differences in RPE encoding and reliability.

Main Results:

• RPE encoding is valence-dependent: positive RPEs are mainly in the striatum, negative RPEs in the insula.
• Negative RPE encoding in the right insula demonstrates high reliability across both 3-month and 3-year intervals.
• Striatal RPE encoding reliability is less consistent but significant when controlling for confounds; task activation in the striatum is highly reliable.

Conclusions:

• The insula shows robust and reliable encoding of negative RPEs in youth, making it a stable marker.
• Differential encoding of RPEs based on valence (positive vs. negative) is evident between the striatum and insula.
• Characterizing reliable RPE encoding regions is essential for longitudinal studies of reward processing alterations in development and clinical populations.