If the tendency to discount rewards reflects individuals' general level of impulsiveness, then the discounting of delayed and probabilistic rewards should be negatively correlated: The less a person is able to wait for delayed rewards, the more they should take chances on receiving probabilistic rewards. It has been suggested that damage to the ventromedial prefrontal cortex (vmPFC) increases individuals' impulsiveness, but both intertemporal choice and risky choice have only recently been assayed in the same patients with vmPFC damage. Here, we assess both delay and probability discounting in individuals with vmPFC damage ( n = 8) or with medial temporal lobe (MTL) damage ( n = 10), and in age- and education-matched controls ( n = 30). On average, MTL-lesioned individuals discounted delayed rewards at normal rates but discounted probabilistic rewards more shallowly than controls. In contrast, vmPFC-lesioned individuals discounted delayed rewards more steeply but probabilistic rewards more shallowly than controls. These results suggest that vmPFC lesions affect the weighting of reward amount relative to delay and certainty in opposite ways. Moreover, whereas MTL-lesioned individuals and controls showed typical, nonsignificant correlations between the discounting of delayed and probabilistic rewards, vmPFC-lesioned individuals showed a significant negative correlation, as would be expected if vmPFC damage increases impulsiveness more in some patients than in others. Although these results are consistent with the hypothesis that vmPFC plays a role in impulsiveness, it is unclear how they could be explained by a single mechanism governing valuation of both delayed and probabilistic rewards.

We report a case study of an individual (TE) for whom inanimate objects, such as letters, numbers, simple shapes, and even furniture, are experienced as having rich and detailed personalities. TE reports that her object-personality pairings are stable over time, occur independent of her intentions, and have been there for as long as she can remember. In these respects, her experiences are indicative of synesthesia. Here we show that TE's object-personality pairings are very consistent across test-retest, even for novel objects. A qualitative analysis of TE's personality descriptions revealed that her personifications are extremely detailed and multi-dimensional, and that her personifications of familiar and novel objects differ in specific ways. We also found that TE's eye movements can be biased by the emotional associations she has with letters and numbers. These findings demonstrate that synesthesia can involve complex semantic personifications, which can influence visual attention. Finally, we propose a neural model of normal personification and the unusual personifications that accompany object-personality synesthesia.