Persistent representation of a prior schema in the orbitofrontal cortex facilitates learning of a conflicting schema

TL;DR

The orbitofrontal cortex helps the brain learn new rules by keeping track of old ones, which surprisingly speeds up learning when rules conflict.

Contribution

The study reveals that persistent representation of prior schemas in the OFC facilitates learning of conflicting schemas.

Findings

OFC neurons adapt to track underlying rules during learning.

Persistent prior schema representation predicts faster acquisition of new conflicting rules.

Disrupting OFC activity during initial learning impairs later learning of a new schema.

Abstract

Schemas allow efficient behavior in new situations, but reliance on them can impair flexibility when new demands conflict. Evidence implicates the orbitofrontal cortex (OFC) in deploying schemas in new situations. But how does this role affect learning of a conflicting schema? Here we addressed this question by recording or transiently inactivating OFC neurons in rats learning odor problems with identical external information but orthogonal rules governing reward. OFC representations adapted to track the underlying rules, and both performance and encoding were faster on subsequent than initial problems. Surprisingly, when the rule changed, persistent representation of the prior schema predicted faster acquisition of the new, and disrupting OFC activity during initial schema learning, later impaired acquisition of the second schema. Thus, rather than interfering with new learning, OFC neural activity was linked to improved acquisition by preserving accurate representations of the prior schema alongside the new one.

How the brain adjusts its internal knowledge structures when new rules clash with old ones remains unclear. This study shows that OFC neurons hold on to earlier schemas in a way that helps to learn a new, conflicting schema.

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