Encoding Of Effort Cost By Dorsal Anterior Cingulate Cortex In Economic Decisions

In economic decisions,a chooser weighs the costs and benefits for each alternative and chooses the one that maximizes the net payoff.Behaviors like this suggest the presence of a brain mechanism that integrates value attributes concerning effort costs and gains,which allows for the evaluation of multiple alternatives along a common utility scale.Based mainly on the findings from anterior cingulate cortex(ACC)lesioned lesioned rodents,early studies suggested that the ACC may be a brain area involved in proessing effort cost.However,recent studies showed that dorsal anterior cingualte cortex(dACC)only encodes post decision variables such as chosen value and chosen juice rather than pre-decision variables such as offer value.Such results implicate that dACC may represent action-related rewards and costs downsteam of decisions.In the mean time,Current studies targeting encoding and integration of effort cost suffer from several pitfalls:(1)lack of quantitative measure of subjective effort cost;(2)not being able to distinguish whether the encoding of effort was during choice process or effort execution.We tackled these issues through innovative experimental design and approach: Using awake behaving monkeys and an economic choice paradigm with variable action costs,we studied how dACC encodes and integrates effort cost.We discovered that dACC neurons encode the value and effort cost associated with the chosen option.Furthermore,encoding of chosen cost emerges only after potential action plans are revealed to the animal.Taken together,our study suggests that in economic decisions under variable action costs,dACC may be involved in minotoring the effort cost associated with the chosen option for initiating and sustaining appropriate motor plans for obtaining the chosen reward.