# Multi-level encoding of reward, effort, and choice across the frontal cortex and basal ganglia during cost-benefit decision-making

## TL;DR

The study shows how the brain processes decisions involving rewards and effort by coordinating individual neurons and groups of neurons across different brain regions.

## Contribution

The paper reveals a multi-level encoding structure in the frontal cortex and basal ganglia for cost-benefit decision-making using coordinated neural assemblies.

## Key findings

- Single neurons and coactive assemblies encode reward, effort, and choice during cost-benefit decisions.
- Coactive assemblies can represent decision variables independently of individual neuron properties.
- Rate and temporal codes may support parallel computations in the same neural circuit.

## Abstract

Adaptive value-guided decision-making requires weighing up the costs and benefits of pursuing an available opportunity. Though neurons across frontal cortical-basal ganglia circuits have been repeatedly shown to represent decision-related parameters, it is unclear whether and how this information is coordinated. To address this question, we performed large-scale single-unit recordings simultaneously across 5 medial/orbital frontal and basal ganglia regions as rats decided whether to pursue varying reward payoffs available at different effort costs. Single neurons encoding combinations of decision variables (reward, effort, and choice) were represented within all recorded regions. Coactive cell assemblies, ensembles of neurons that repeatedly coactivated within short time windows (<25 ms), represented the same decision variables despite the members often having diverse individual coding properties. Together, these findings demonstrate a multi-level encoding structure for cost-benefit computations where individual neurons are coordinated into larger assemblies that can represent task variables independently of their constituent components.

•Neurons were recorded across the frontal-basal ganglia network during cost-benefit decisions•Firing rate codings of reward, effort, and choice were temporally and spatially heterogeneous•An emergent temporal code across these neurons is independent of the rate representations•Rate and temporal codes may support parallel computations within the same circuit

Neurons were recorded across the frontal-basal ganglia network during cost-benefit decisions

Firing rate codings of reward, effort, and choice were temporally and spatially heterogeneous

An emergent temporal code across these neurons is independent of the rate representations

Rate and temporal codes may support parallel computations within the same circuit

Härmson et al. show that single neurons and coactive assemblies across the medial cortico-basal ganglia circuit encode combinations of reward, effort, and choice during cost-benefit decision-making. Assemblies comprised individual neurons with diverse coding properties, suggesting they can coordinate information into lower-dimensional spaces within and across brain regions.