A mechanism for value-guided choice based on the excitation-inhibition balance in prefrontal cortex.

Although the ventromedial prefrontal cortex (vmPFC) has long been implicated in reward-guided decision making, its exact role in this process has remained an unresolved issue. Here we show that, in accordance with models of decision making, vmPFC concentrations of GABA and glutamate in human volunteers predict both behavioral performance and the dynamics of a neural value comparison signal. These data provide evidence for a neural competition mechanism in vmPFC that supports value-guided choice.