The effort provides insight, scientists say, into the capacity for "mental time travel," also known as episodic future thought, that enables humans to make choices with high long-term benefits. Results of the research are published in Neuron.
Several models have been proposed to explain the neural basis of assigning relative value to multiple rewards at different points in time (also known as "intertemporal decision making") in humans. Until now, however, many questions remained unanswered, and the brain regions and mechanisms involved in this process were unclear.
For the study, researchers used functional magnetic resonance imaging (fMRI), neural coupling analyses, and extensive behavioral paradigms to examine the interactions between episodic future thought and intertemporal decision making.
Participants had to make a series of choices between smaller immediate and larger delayed rewards while brain activity was measured with fMRI. Importantly, in addition to this standard control condition, the participants were presented with "cues" that referred to real subject-specific future events planned for the respective day of reward delivery. The researchers observed that the more the cues induced spontaneous episodic imagery, the more subjects changed their preferences toward patient, future-minded choice behavior.
Further, the neuroimaging data revealed that signals in the anterior cingulate cortex (ACC), a part of the brain implicated in reward-based decision making, and functional coupling of this region with the hippocampus, linked with imagining the future, predicted the degree to which forward thinking modulated individual preference functions.
Citation: Jan Peterssend, Christian Büchel, 'Episodic Future Thinking Reduces Reward Delay Discounting through an Enhancement of Prefrontal-Mediotemporal Interactions', April 2010, 66(1), 138-148; doi: 10.1016/j.neuron.2010.03.026