Temptation: The Effects of Immediate and Delayed Rewards
As we approach the loved holiday season, we also approach the dreaded weight gain that comes along with it. It probably won’t come as a surprise to you that our brain, specifically the hippocampus, plays a role in resisting immediate or delayed temptation.
The hippocampus deals with memory, including recalling past events and imagining them in the future. A study called “A Critical Role for the Hippocampus in the Valuation of Imagined Outcomes” examines healthy people as well as people with Alzheimer’s disease, which impairs memory and is associated with atrophy of the hippocampus. The study looked at “time- dependent” choices having to do with money in addition to “episodic” choices having to do with food, sports, and cultural events.
Fifteen participants were given a series of decisions about choosing one reward over another, where one reward is immediate and the other is delayed. Some of the rewards were shown in a picture format and others were just given in a text format where the participants would imagine what the reward would be. Participants tended to choose the delayed reward when it was described in text, assumedly because it forced them to imagine in more detail.
In another, similar experiment, twenty participants faced the same kinds of decisions. The researcher concluded that research participants were consistent with themselves in what they chose, reflecting their individual impulsiveness. Depending on the person, they would choose the immediate reward or they were willing to choose the delayed reward, regardless of how it was presented. The researcher argued that there was a case to argue about an “impulsive trait” in some participants but not in others. This experiment also had a functional magnetic resonance image (fMRI) component in order to look at the activation patterns in the hippocampus. The results found that the hippocampus was more active when the reward options were given in the text format because it forced the participant to be more imaginative and relate them to previous memories.
When using participants with Alzheimer’s, researchers found that these people tended to choose the reward shown in pictures rather than written in text. Researchers believe that the damage to the hippocampus in Alzheimer’s patients is extremely significant in evaluating these results, as it hinders their recall of positive food memories.
What did we learn? Well, with such a small sample size, there is a lot more research to be done to determine what the relationship between impulsive behaviors and brain activity is. There is currently a lot of research being done on the areas of the brain most associated with self- control.
How can we use this to help us this holiday season? Maybe this is a lesson in how certain foods are presented to us. It seems that according to these results, we will eat less with the food presented visually to us as opposed to on a written menu. And, maybe when trying to decide whether to have that last piece of pie, try not to imagine it. Have a happy holiday season!
CNN: Resisting Temptation – CNN Health