Approach–Avoidance Processes Contribute to Dissociable Impacts of Risk and Loss on Choice

Abstract

Value-based choices are influenced both by risk in potential outcomes and by whether outcomes reflect potential gains or losses. These variables are held to be related in a specific fashion, manifest in risk aversion for gains and risk seeking for losses. Instead, we hypothesized that there are independent impacts of risk and loss on choice such that, depending on context, subjects can show either risk aversion for gains and risk seeking for losses or the exact opposite. We demonstrate this independence in a gambling task, by selectively reversing a loss-induced effect (causing more gambling for gains than losses and the reverse) while leaving risk aversion unaffected. Consistent with these dissociable behavioral impacts of risk and loss, fMRI data revealed dissociable neural correlates of these variables, with parietal cortex tracking risk and orbitofrontal cortex and striatum tracking loss. Based on our neural data, we hypothesized that risk and loss influence action selection through approach-avoidance mechanisms, a hypothesis supported in an experiment in which we show valence and risk-dependent reaction time effects in line with this putative mechanism. We suggest that in the choice process risk and loss can independently engage approach-avoidance mechanisms. This can provide a novel explanation for how risk influences action selection and explains both classically described choice behavior as well as behavioral patterns not predicted by existing theory.

Social closeness and feedback modulate susceptibility to the framing effect

“…Given the involvement of the vmPFC in complex decision making (Rangel et al 2007; Hare et al, 2009, 2010; Zaki et al, 2011; Wright et al, 2012) particularly in value-based decision making (Clithero & Rangel 2013), including decisions framed as gains or losses (De Martino et al, 2006), we chose the vmPFC as a key region of exploration. Interestingly, one key difference between our study where intermittent SFB was provided and prior investigations where expert advice was given (e.g., Engelmann et al, 2012), was that there was no expectation to follow the feedback (unlike the advice).…”

Assaying the Effect of Levodopa on the Evaluation of Risk in Healthy Humans

“…Here we employed a within-subject design with twenty subjects tested on two separate occasions, which potentially could induce a desire for consistency in choice behavior and explain a lack of effect. However, this paradigm and closely related tasks with similar sample sizes have been used to delineate changes in risk-preference induced by physiological manipulations such as hunger and satiety [36] and psychological manipulations such as making decisions for losses versus gains [37].…”

The chronometry of risk processing in the human cortex

“…Skewness captures an implicit relative comparison of better than average to worse than average outcomes, hence we speculate that these alpha power changes may be involved in quantifying an asymmetry in valence of outcomes. Approach-avoidance processes are implicated in decision-making for gains and losses, and are distinct from processing of variance (Wright et al, 2012). However, it remains to be determined if skewness is encoded entirely independently of valence.…”