fMRI evidence for procedural invariance underlying gambling preference reversals

Preference reversals (PRs) occur when one's preferences over the same items change depending upon how one is asked to construct a preference. PRs are a robust phenomenon that lead to suboptimal real-world decision making. Despite this, it remains unclear why PRs occur. This study investigated whether biological procedural invariance (i.e., different procedures are associated with different underlying mechanisms) could elucidate why PRs occur. Seventeen participants were scanned via functional MRI (fMRI) while (a) expressing preferences between 2 probabilistic wins or 2 probabilistic losses (1 high and 1 low magnitude) and, (b) reporting a monetary amount (valuation) according to how much they wanted to sell a potential winning gamble for or how much they would pay to forgo a potential loss. Participants' valuations closely followed expected value. Choice behavior, however, was more prone to bias because of unequal weighting of either magnitude or probability. Preference formation during both valuation and choice was associated with fronto-parietal neural activity. Within this system, valuation was associated with greater activity in dorsolateral prefrontal cortex and caudal anterior cingulate cortex, while choice was associated with greater activity in the insula, horizontal inferior parietal sulcus, posterior cingulate cortex, and somatosensory cortex. The combination of behavioral and neuroimaging data may suggest that participants used a mathematical approach to formation of valuations but choices were subject to emotional influence. These findings may provide support for a biological procedural invariance view of gambling preference reversal. These findings are difficult to accommodate within explanations that rely on modifications to expected utility and prospect theory