Norepinephrine and Neuronal Dynamics in the Anterior Cingulate Cortex: Effects on Decision-Making Across Internal States

Abstract

Internal states such as attention, arousal, and motivation affect decision-making. For example, hunger increases risk-taking behavior, while actively attending to a task increases accuracy and performance. To guide decision-making, task-relevant sensory stimuli and internal states need to be integrated, which potentially happens in the anterior cingulate cortex (ACC). The ACC has been implicated in encoding choice-relevant task variables and in strategy changes that give rise to behavioral flexibility. The ACC also forms bidirectional connections with the Locus Coeruleus, a brain region that is the primary source of the neuromodulator norepinephrine (NE). NE release has been shown to modulate internal states such as arousal and attention. However, the dynamics of NE and neural activity in the ACC during a cognitively demanding task and across internal states are unknown. Here, we discover distinct NE patterns corresponding to kinematic and cognitive variables, such as speed and reward expectancy. Additionally, we show a multiplexed encoding of task variables by neurons in the ACC, including the encoding of internal states related to task engagement. Our results demonstrate the central role of the ACC during cognitively demanding decision-making and the potential for NE and internal states to shape neural dynamics. Further understanding how neuromodulation and internal states act together on brain regions important for decision-making, is crucial for understanding how flexible decision-making is achieved.