How the anterior cingulate cortex and the hippocampus represent a decision making task: a population encoding approach

The anterior cingulate cortex (ACC) appears to be involved in cognitive control, learning, and memory. Recent proposals integrating these functions suggest that the ACC embodies a cognitive map of task space. In this view, ACC links decision and reward information to particular locations in an abstract map of a task environment, allowing for planning and control. Here, I present novel evidence for task space by showing that, in rats, ACC spatial ensemble activity is preserved when performing a task on a familiar layout, but in a novel spatial context. Furthermore, this encoding similarity is sufficient to decode the animal's position in the new context using the “map” of the familiar layout. I contrast this with hippocampal activity and encoding, which drastically changes when switching spatial contexts. This sheds light into how the brain might encode decision and reinforcement information together with spatial cues to exert top-down control on behavior