Coexistence of sensory qualities and value representations in human orbitofrontal cortex

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Decision Science

Background:

• The orbitofrontal cortex (OFC) is crucial for value-based decision-making.
• Its precise role in representing outcome identity, sensory qualities, and subjective values is unclear.
• Reinforcer devaluation tasks have implicated the OFC, but specific representations remain debated.

Purpose of the Study:

• To investigate whether the human OFC represents object identity, sensory qualities, or value.
• To dissociate these representations using a large set of stimuli and controlled experimental conditions.
• To clarify the OFC's function in representing outcome attributes during decision-making.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to measure brain activity.
• Participants rated the palatability of 128 food items presented as photographs.
• Representational similarity analysis (RSA) was employed to analyze neural representations.

Main Results:

• Palatability ratings decreased significantly after a meal, indicating a change in value.
• Representational similarity analysis confirmed that the OFC represents value.
• Lateral OFC representations of identical items changed post-feeding, correlating with sensory quality but not subjective value.

Conclusions:

• The human orbitofrontal cortex (OFC) represents both sensory quality and value.
• The OFC does not appear to represent object identity independently of these factors.
• Findings clarify the OFC's role in encoding outcome attributes relevant to decision-making.