Environmental complexity modulates information processing and the balance between decision-making systems

Area of Science:

• Neuroscience
• Behavioral Science
• Cognitive Science

Background:

• Naturalistic behavior involves complex environments and competing neural systems.
• Previous rodent decision-making studies often used simplified environments.
• Understanding neural circuit dynamics in complex settings is crucial for adaptive strategies.

Purpose of the Study:

• To investigate neural ensemble activity in the hippocampus (HC), dorsolateral striatum (DLS), and dorsomedial prefrontal cortex (dmPFC) during foraging in complex environments.
• To elucidate the role of these brain regions in decision-making under varying environmental complexity and rules.
• To explore the competition between neural decision systems and the regulatory function of the dmPFC.

Main Methods:

• Recorded neural ensembles from HC, DLS, and dmPFC in rats foraging under changing rules and varying environmental complexity.
• Analyzed behavioral variability, HC nonlocal sequences, and action caching.
• Utilized inactivation of the dmPFC to assess its causal role in behavioral adaptation and decision system balance.

Main Results:

• Environmental complexity increased behavioral variability, lengthened HC nonlocal sequences, and modulated action caching.
• Contrasting neural representations were observed between DLS and HC, suggesting system competition.
• dmPFC activity predicted the balance between HC and DLS engagement, and its inactivation impaired adaptation.

Conclusions:

• Decision-making systems exhibit dynamic engagement modulated by environmental complexity.
• The dmPFC plays a critical role in balancing competing neural systems for adaptive behavior.
• Findings provide insights into naturalistic decision-making and its neural underpinnings.