Selected Publications
Modeling incentive salience in Pavlovian learning more parsimoniously using a multiple attribute model
Although almost 200 temporal discounting experiments using functional magnetic resonance imaging are described in literature, there has not been a meta-analysis identifying regions activated when subjects choose SmallerSooner versus LargerLater alternatives. Evidence suggests a prefrontal cortex ‘abstraction hierarchy’, from abstract planning in more anterior regions to concrete processing in posterior regions. Because more distant future prospects are represented more abstractly, we hypothesized that LargerLater choices would be associated with more anterior PFC activation while SmallerSooner choices would be associated with more posterior activation. We examined the literature for temporal discounting tasks comparing decisions where subjects chose SmallerSooner vs. LargerLater rewards, and identified thirteen studies including 436 subjects which we tested in an SDM neural meta-analysis. We observed LargerLater activity anterior of SmallerSooner activity, both in the left inferior frontal gyrus pars triangularis, consistent with our pre-registered hypothesis that LargerLater would be observed anterior of SmallerSooner activity. We call for further work investigating links between temporal discounting representation and the processing of abstract and concrete information in the prefrontal cortex.
NBR
A meta-analytical review of brain activity associated with intertemporal decisions: Evidence for an anterior-posterior tangibility axis
Although almost 200 temporal discounting experiments using functional magnetic resonance imaging are described in literature, there has not been a meta-analysis identifying regions activated when subjects choose SmallerSooner versus LargerLater alternatives. Evidence suggests a prefrontal cortex ‘abstraction hierarchy’, from abstract planning in more anterior regions to concrete processing in posterior regions. Because more distant future prospects are represented more abstractly, we hypothesized that LargerLater choices would be associated with more anterior PFC activation while SmallerSooner choices would be associated with more posterior activation. We examined the literature for temporal discounting tasks comparing decisions where subjects chose SmallerSooner vs. LargerLater rewards, and identified thirteen studies including 436 subjects which we tested in an SDM neural meta-analysis. We observed LargerLater activity anterior of SmallerSooner activity, both in the left inferior frontal gyrus pars triangularis, consistent with our pre-registered hypothesis that LargerLater would be observed anterior of SmallerSooner activity. We call for further work investigating links between temporal discounting representation and the processing of abstract and concrete information in the prefrontal cortex.
NBR
Virtually 'in the heat of the moment': Insula activation in safe sex negotiation among risky men.
HIV is most prevalent among men who have sex with men (MSM), and although most MSM use condoms consistently during casual sex, some take risks. To better understand the psychology of those risky decisions, we examined neural correlates of playing a virtual sexual “hook up” game in an fMRI scanner in MSM who had, in the past 90 days, been sexually risky (N=76) or safe (N=31). We found that during potentially risky sexual choices, previously risky MSM had more right insula activity than previously safe MSM. Real-life sexual risk was related to trait positive and negative urgency. Insula activity which differentiated risky and safe MSM was related to trait positive and negative urgency. Future work should further examine if, and to what extent, insula activation during safe sex negotiation drives MSM’s rash risky sexual decision-making.
SCAN
Virtual Personalities: Using computational modeling to understand within-person variability
How can the same underlying psychological/neurobiological system result in both stable between-individual differences and high levels of within-individual variability in personality states over time and situations? We argue that both types of variability result from a psychological system based on structured, chronic motivations, where behavior at a specific point in time is a joint function of the current availability of motive affordances in the situation, current motivationally relevant bodily or interoceptive states, and the result of the competition among alternative active motives. Here we present a biologically-based theoretical framework, embodied in two different computational models, that shows how individuals with stable personality characteristics, can nevertheless exhibit considerable within-person variability in personality states across time and situations.
JRP
