Midbrain signaling of identity prediction errors depends on orbitofrontal cortex networks

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Decision Neuroscience

Background:

• Outcome-guided behavior relies on anticipating future rewards.
• The dopaminergic midbrain signals reward identity prediction errors.
• The lateral orbitofrontal cortex (OFC) is implicated in representing reward identity expectations.

Purpose of the Study:

• To investigate if lateral OFC outcome expectations contribute to midbrain identity prediction errors (iPE).
• To test the hypothesis using network-targeted transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI).

Main Methods:

• Network-targeted TMS applied to the lateral OFC during a trans-reinforcer reversal learning task.
• fMRI recorded brain activity during the learning task.
• Analysis focused on global connectedness of the OFC and iPE responses in the midbrain.

Main Results:

• TMS targeting the lateral OFC reduced its global connectedness.
• Disruption of the lateral OFC impaired reward identity learning.
• TMS modulated neural representations of expected reward identity in the OFC and altered midbrain iPE responses.

Conclusions:

• Identity prediction errors in the dopaminergic midbrain are computed using outcome expectations from the lateral OFC.
• The lateral OFC plays a critical role in reward identity learning and expectation updating.