Jean-Claude Dreher has invited Todd Hare from the University of Zurich to come and give a talk at ISC about:
The effects of acute stress on behavioral and neural measures of self-control.
Dietary self-control requires the integration of short-term taste and long-term health aspects into an overall value for a food item. On a neural level, previous work has shown that the ventromedial prefrontal cortex (vmPFC) and ventral striatum, and amygdala are part of a valuation system that represents such values. Little is known, however, about the impact of acute stress on these neural mechanisms and subsequent dietary choices. We examined choice behavior and neural activity with BOLD fMRI after participants were exposed to an acute stressor (Socially Evaluated Cold Pressor). We found differences in choice patterns and neural activity during dietary self-control choices following our stress manipulation. Salivary cortisol and self-report measures indicated a successful stress induction. At the level of choice, both groups generally followed the health goal and chose the healthier item more than 70% of the time. However, further analysis of the choice patterns showed that the stress group put more weight on taste during choice than controls. Paralleling their choice behavior, the stressed group showed stronger representations of taste attributes in the amygdala and ventral striatum compared to controls. Moreover, there was greater connectivity between these limbic regions and areas of vmPFC that reflected the overall value of foods when stressed subjects chose to eat more tasty food options. Lastly, activity in the dorsolateral prefrontal cortex (dlPFC) increased when exercising self-control in both stressed and control subjects. However, the degree of connectivity between dlPFC and vmPFC decreased as a function of stress level. These results suggest that differential patterns of connectivity between vmPFC and both cortical and limbic regions may underlie the more taste-oriented behavior following acute stress.
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