Orbitofrontal High-Gamma Reflects Spike-Dissociable Value and Decision Mechanisms.

Area of Science:

• Neuroscience
• Decision Science
• Brain-Computer Interfaces

Background:

• The orbitofrontal cortex (OFC) is vital for value-based decision-making.
• Understanding neural signals in the OFC, particularly local field potentials (LFPs), is crucial for deciphering decision processes.
• LFPs may offer insights into subthreshold neural activity and potential targets for brain-machine interfaces (BMIs).

Purpose of the Study:

• To compare the value- and decision-coding properties of high-gamma (HG) LFPs with multiunit activity (MUA) in the OFC.
• To investigate novel information encoded in OFC LFPs during value-based decisions.
• To assess the potential of HG LFPs as a target for cognitive-assistive BMIs.

Main Methods:

• Recorded concurrent HG LFPs and MUA from the OFC of male macaques during a two-option value-based decision task.
• Analyzed and compared the representation of target values and decision outcomes in both signal types.
• Utilized single-channel and population-based decoding analyses.

Main Results:

• Both HG LFPs and MUA encoded target values, but with distinct characteristics.
• HG amplitude showed monotonic value encoding, unlike the net-neutral encoding in MUA.
• HG signals reflected value comparisons, a feature largely absent in MUA.
• Individual HG channels predicted choice outcomes better than MUA, but population MUA decoding was more accurate.

Conclusions:

• OFC HG LFPs provide unique insights into value representation and comparison not evident in spiking activity.
• HG signals offer potential for more accurate behavioral prediction in certain contexts.
• High-frequency LFPs represent a promising target for developing advanced cognitive-assistive BMIs.