Natural Rationality | decision-making in the economy of nature


Anterior cingulate choices and orbitofrontal preferences

With all the studies in neuroeconomics, it is hard to get the whole picture of decision-making. In a paper in Trends in Cognitive Science, Rushworth et al. review the contribution of two important areas: the anterior cingulate cortex (ACC) and orbitofrontal cortex (OFC). After reviewing many studies, the authors conclude that they substantially contribute , respectively, to the generation of reward-based action and to representation of value. The OFC thus encodes values, expectations and preferences (patient with OFC lesions are impaired in their decision-making abilities because they cannot asses the utility of different options). The ACC is more concerned about the values of action and the generation of exploratory actions and their valuation. Thus, to make an extremely simplistic description, OFC is about preferences and ACC about choices, the two most important components of decision making: in making a rational decision, one chooses to do A because one prefers A to other options:

The OFC is important when reinforcement is associated with stimuli and for the representation of preferences. It is critical when behaviour depends on detailed, flexible and adjustable predictions of outcomes or on models of the reinforcement environment. In the ACC, reward representation is closely bound to action or task representation. This means that the ACC mediates the relationship between the previous action-reinforcement history and the next action choice.
ACC is also more involved in social cognition.

The following image depicts the connections between OFC, ACC and other areas. As you can see, OFC is a little more on the "input side" while ACC is on the "ouptut side". In both cases, the amygdala (involved in fear, memory, learning and attention) and the ventral striatum (reward processing and motivation) are important players in this game:

We are far from having the whole picture, or a neuroeconomic Theory of Everything, but these syntheses help understanding the mechanisms of decision-making. The next big step, I guess, would be the integration of this connectivity pattern with the function of dopaminergic neurons, thought to implements TD-learning algorithms (see this previous post)

In any case, whatever will be the details, it is clear that a theory of decision-making will be a theory of "affective management". In a historical-philosophical perspective, all these researches can be seen as a reactualization of the intellectualism/voluntarism dispute According to intellectualism, a rational action is the product of a reasoning process that determines what is good, while voluntarism take the action as the product of a motivation. Neuroeconomics, hedonic psychology and affective cognition all suggest a contemporary form of voluntarism.