Modeling risky decision-making in nonhuman animals: shared core features

Abstract

Understanding the neural mechanisms of risky decision-making is critical to developing appropriate treatments for psychiatric disorders, problem gambling, and addiction to drugs of abuse. Probing neurobiological mechanisms requires the use of nonhuman animal models (particularly rhesus macaques, rats, and mice). However, there is considerable variation across species in risk preferences. Nevertheless, there are shared core features of risky decision-making present across species. As demonstrated with a wide variety of behavioral paradigms, modulators of risk preference observed in humans are readily replicated in model species. Thus, risky decision-making represents an important implementation of reward-guided decision-making that is feasibly modeled across species.

Figure 1

The experience-description gap in risky choice, as assessed in rhesus monkeys (left, adapted from [41]) and humans (right, adapted from [42]). In both cases, there were two types of gambles: those explicitly cued (top row) and those whose probabilities were learned through experience (second row). There was also a safe option in each case (third row). Both monkeys and humans chose the risky option more often when it was learned through experience than when it was explicitly cued/described (bottom row).

Figure 2

Near miss paradigms in rodents (left, adapted from [27]) and humans (right, adapted from [49]). Rodents face trials in which 0–2 lights illuminated is followed by no reward, but 3 lights illuminated is followed by a reward. 0–1 lights illuminated are treated as a clear loss, but 2 lights illuminated is treated as a near-miss. Humans face a slot-machine-like paradigm in which stimuli at the center must align in order to win. A near-miss is a misalignment by one row, while a clear loss is a misalignment by >1 row.