The value of the whole or the sum of the parts: The role of ventromedial prefrontal cortex in multi-attribute object evaluation

Everyday decision-making commonly involves assigning values to complex objects with multiple value-relevant attributes. Drawing on what is known about complex object recognition, we hypothesized two routes to multi-attribute evaluation: assessing the value of the whole object based on attribute configuration, or summing individual attribute-values. In two samples of healthy human participants undergoing eye-tracking and fMRI while evaluating novel pseudo-objects, we found evidence for distinct forms of multi-attribute evaluation. Fixations to, and transitions between attributes differed systematically when value was associated with individual attributes or attribute configurations. Further, ventromedial prefrontal cortex (vmPFC) and the perirhinal cortex were engaged during evaluation specifically when configural processing was required. These results converge with our recent findings that damage to vmPFC disrupts decisions when evaluation requires configural processing, and not in evaluating "the sum of the parts". This suggests that multi-attribute decisions may engage distinct evaluation mechanisms relying on partially dissociable neural substrates.