Mechanisms of behavioral change targeting automatic processes
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In order to eliminate unhealthy behaviors, one must find ways to make better choices. Changing preferences is an important strategy in addressing public health concerns such as the obesity epidemic. In this dissertation, I present several lines of research, which all aim to influence choice behavior. First, we developed a novel extensive training paradigm that uses monetary reinforcement to influence choices for less desired palatable foods over initially more preferred foods. We found that, as reinforced training progressed, there was decreased recruitment of a frontoparietal network of brain regions that have been previously associated with cognitive control. We also found neural evidence that suggests formation of a stronger stimulus-response association as reinforced training progressed. These findings demonstrate that it is possible to influence food choices through reinforcement and that training is associated with a decreasing need for top-down frontoparietal control. However, the long term durability of this change in choice behavior is in question. Learning theory predicts a return to choosing the initially more preferred item simply with the passage of time, despite overtraining the new behavior. Thus, we turned our efforts toward targeting automatic processes to achieve a lasting shift in choice behavior. We found that our attempts to interfere with memory traces for an established choice or to train bottom-up inhibition to avoid particular food items were unsuccessful. However, we found that driving sustained attention toward particular food items at behaviorally relevant points in time during cue-approach training robustly influences choice preferences in favor of those items. Imaging results show that value representation for those items in the ventromedial prefrontal cortex is amplified. Finally, we found that spacing cue-approach training trials over multiple days benefits the long-term maintenance of the cue-approach choice effect. Results presented in this dissertation lay the groundwork for new insights into mechanisms of behavioral change and value-based decision making more broadly as well as suggest some strategies for developing real-world intervention paradigms to help those seeking to adopt and maintain healthier habits.