Neuroeconomics

Chapter 4 endnote 57, from How Emotions are Made: The Secret Life of the Brain by Lisa Feldman Barrett.
Some context is:

It doesn’t matter whether you’re choosing between two snacks, two job offers, two investments, or two heart surgeons ​— ​your everyday decisions are driven by a loudmouthed, mostly deaf scientist who views the world through affect-colored glasses. [...] Neuroeconomics seeks to understand how the brain estimates the value of different choices to allow decision-making. Value and affect are related concepts.

Neuroeconomics is a branch of economics that seeks to identify the brain areas that contribute to decision-making. Neuroeconomists study why someone chooses one food over another, buys a particular stock, or takes a calculated risk. They measure behaviors rather than affective feeling. What matters to a neuroeconomist is not whether you like one food better than another (affect), but whether you are willing to work or pay for one food over another; this is the concept of “value.” If you take an action by choosing an option, then that option (be it an object or an event) had value to you, or else you wouldn’t have chosen it.

In defining value by actions and ignoring the potential importance of affect, neuroeconomics is an elegant version of behaviorism. Some neuroeconomists actively eschew the idea that affect influences decision-making. They are similar to the methodological behaviorists who believed that conscious experience is epiphenomenal to the human condition and that only behaviors can be studied scientifically (i.e., they assume affect has no causal influence on outcomes).

Other neuroeconomists do not deny that affect plays an important role in decision-making, but they (rightly) point out that it is currently impossible to measure affect in a completely objective way (that is, without relying on test subjects’ own reports of how they feel).

In studies on nonhuman animals, neuroeconomists have found evidence that neurons within regions of the interoceptive network that are linked to affect also predict subjective “value” and thereby direct decision-making. When neurons in the vmPFC and ventral striatum (and necessarily the sACC which lies directly between them) fire, they predict the animal’s choice behavior.

The neuroeconomist Antonio Rangel has conducted a particularly elegant series of experiments on how people decide value in simple choices. The paper being cited here, Clithero & Rangel (2013), reports a meta-analysis of 81 neuroimaging studies, showing that sACC to vmPFC are consistently engaged when test subjects are deciding and receiving things they value but not necessarily what they like (affect). Rangel believes that these neurons allow people to compare different classes of objects (food, money, trinkets) on a common currency, so that we can decide which ones we prefer. But what is this common currency? Neuroeconomists would say it is "value," but perhaps value is computed in relation to the brain's body budget.