Effect of neuromodulation on performance in game playing: A modeling study

Neuromodulators can have a strong effect on how organisms learn and competefor resources. Neuromodulators, such as dopamine (DA) and serotonin (5-HT), are known to be important in predicting rewards, costs, and punishments. To better understand the effect of neuromodulation on decision-making, a computational model of the dopaminergic and serotonergic systems was constructed and tested in games of conflict. This neural model was based on the assumptions that dopaminergic activity increases as expected reward increases, and serotonergic activity increases as the expected cost of an action increases. Specifically, the neural model guided the learning of an agent that played a series of Hawk-Dove games against an opponent. The model responded appropriately to changes in environmental conditions or to changes in its opponent´s strategy. The neural agent became Dove-like in its behavior when its dopaminergic system was compromised, and became Hawk-like in its behavior when its serotonergic system was compromised. Our model suggests how neuromodulatory systems can shape decision-making and adaptive learningin competitive situations.