Prediction error for free monetary reward in the human prefrontal cortex

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Neuroimaging

Background:

• Predicting future rewards is vital for primates.
• Dopamine neurons in monkeys signal reward prediction errors.
• Human brain mechanisms for monetary reward prediction error are poorly understood, especially when rewards are not behavior-contingent.

Purpose of the Study:

• To investigate human brain activity related to monetary reward prediction errors.
• To differentiate neural responses to unpredicted rewards versus the failure of expected rewards.
• To explore how these systems function when rewards are independent of actions.

Main Methods:

• Event-related functional magnetic resonance imaging (fMRI) was employed.
• Participants predicted monetary rewards or non-rewards based on visual cues.
• Cue-outcome contingencies were occasionally reversed, creating prediction errors.

Main Results:

• Distinct frontotemporal circuits were activated by different prediction errors.
• Failure of expected rewards activated the temporal cortex and frontal pole (Area 10).
• Unpredicted rewards activated the orbitofrontal cortex, frontal pole, parahippocampal cortex, and cerebellum.

Conclusions:

• Specific frontotemporal circuits are involved in processing monetary reward prediction errors in humans.
• These findings suggest a role for these circuits in encoding cue-monetary reward associations.
• The study highlights distinct neural pathways for processing positive and negative prediction errors.