Identifying identity and attributing value to attributes: reconsidering mechanisms of preference decisions

Abstract

Although the orbitofrontal cortex (OFC) robustly encodes value during preference decisions, it also encodes multiple non-value features of choice options. The role of this information, and its relationship to the options' overall value remain open questions. In this opinion, we attempt to disentangle oft-studied categories of option information - identity and attributes - in the context of both classic theories of economic choice and contradicting evidence of choice biases in multi-attribute decisions. In doing so, we aim to set forth considerations for understanding the wide variety of decision-relevant information encoded by the OFC during preference decisions.

Figure 1.. Schematic of two hypotheses for multi-attribute decisions.

A) Decision-making on the basis of integrated value. Each option (A and B) consists of two attributes that are integrated to compute an overall value, and option comparison occurs between these values. B) Decision-making on the basis of attributes. Each option (A and B) again consists of two attributes, but comparison occurs between like attributes without computing the overall option value. Note that we do not posit that these are the only two hypotheses for the process of decision-making, and that the term attribute may refer to a wide variety of option aspects, including quality, time delay, cost, and taste, et cetera, all of which are disparate information sources that may engage different pathways and processing mechanisms. (Created with BioRender.com)

Figure 2.. Example of a neuron encoding integrated value.

The left panel shows patterns of binary choices, fit with sigmoid curves, between two options (A and B), in which each option is a different flavor of juice offered to monkeys in different quantities (x-axis), with different probabilities (X, X”). The flex of the sigmoid determined the indifference point, or the quantities at which A* and B* were chosen with equal probability. The X-axis denotes the ratio of juice B to juice A. The right panel shows mean firing rates of a neuron encoding the value of the chosen option. Activity increased with the subjective value of the chosen option, regardless of whether the animal chose juice A (circles) or juice B (diamonds), and quantitatively reflected the trade-off between juice type, amount, and probability, as measured by the subject’s choice patterns. Adapted from Raghuraman and Padoa-Schioppa [14].

Figure 3.. Summary of context (decoy) effects.

Options 1 and 2 are denoted by solid circles, and lie along a line of equal preference. While option 1 is higher in attribute A and lower in attribute B, and option 2 is lower in attribute A and higher in attribute B, they are nevertheless selected equally in binary choice. The presence of any of the decoys displayed (smaller red options), however, will increase the choice frequency of Option 1 (red). dc = decoy which produces the compromise effect, da = decoy which produces the attraction effect, ds = decoy which produces the similarity effect. The specific attribute arrangement of the decoy is essential for influencing the direction of the effects. (Created with BioRender.com)