# Anterior cingulate cortex mixes retrospective cognitive signals and ongoing movement signatures during decision-making

## TL;DR

This study shows that the anterior cingulate cortex in mice tracks past decisions and outcomes, separate from movement signals, during decision-making.

## Contribution

The study reveals a conserved population code in ACC for trial history that is independent of task environment volatility.

## Key findings

- ACC neurons show nonlinear mixed selectivity for trial history and movement.
- Trial history is encoded in ACC population activity independently of posture and movement.
- Encoding of trial history is consistent across subjects and unaffected by behavioral biases.

## Abstract

In dynamic environments, animals must closely monitor the effects of their actions to inform switches in behavioral strategy. Anterior cingulate cortex (ACC) neurons track decision outcomes in these environments. Yet, it remains unclear whether ACC neurons similarly monitor behavioral history in static environments and, if so, whether these signals are distinct from movement representations. We recorded large-scale ACC activity in freely moving mice making visual evidence-accumulation decisions. Many ACC neurons exhibited nonlinear mixed selectivity for previous choices and outcomes (trial history) and were modulated by movements. Trial history could be stably decoded from population activity and accounted for a separable component of neural activity than posture and movements. Trial history encoding was conserved across different subjects and was unaffected by fluctuating behavioral biases. These findings demonstrate that trial history monitoring in ACC is implemented in a conserved population code that is independent of the volatility of subjects’ task environment.