By Peter M. Vishton, PhD, William & Mary
Edited by Kate Findley and proofread by Angela Shoemaker, Wondrium Daily
Several researchers have described a mental conflict that occurs as we negotiate between decisions that will satisfy our present self at the expense of hurting our future self. Dr. Vishton explains why we’re sometimes willing to pursue pleasures that will harm us in the long run.
VMPFC and Internal Negotiating
Brain imaging work conducted by social psychologist Dan Gilbert and his colleagues has revealed a lot about how the brain mediates these internal negotiations. A key part of the brain involved in this process is referred to as the ventral medial prefrontal cortex (VMPFC).
While there’s some debate as to where exactly the boundaries of the VMPFC region are located, the VMPFC is generally located near the front of the frontal lobes, tucked under the bottom of the frontal cortex region.
The VMPFC is involved in reasoning about emotion-laden stimuli, and more recently, this region has been found to be heavily involved in self-referential processing. If you were lying in an fMRI scanner and asked to think about your experiences, preferences, abilities, and goals, there’d be a substantial surge of activity in that region of the brain.
About six seconds after that increase in activity, there’d be a surge of blood flow into that region. The fMRI precisely records the amount of blood flow to different regions of the brain so we can see which parts of the brain are affected when you perform particular types of reasoning behaviors.
Gilbert’s VMPFC Study
The participants in a 2011 Gilbert study were scanned in an fMRI while they made judgments about how much they would enjoy a range of pleasant tasks. The ratings were: one, not much at all, to four, very much.
In some cases, the participants judged how much they would enjoy doing the tasks within the next 24 hours. In other cases, the participants judged how much they would enjoy doing the tasks in the future, where the future was defined as a year from the date the experiment was being performed.
In addition to ratings of how much they would personally enjoy particular tasks in the present and in the future, the participants also rated how much they thought some other person would enjoy the task. A photo of this person was shown to provide a visual reference, but no detailed information about this person was provided.
Reviewing this study allows us to look at what the brain does when we’re making judgments about the potential enjoyment for ourselves and for others, both in the present and in the future.
Let’s start with you in the present: the VMPFC is very active for this condition. When you think about others, either in the present or the future, this VMPFC activity is substantially reduced.
Additionally, when you think about you in the future, the VMPFC activity drops. You use the same brain systems involved in reasoning when thinking of other people.
In terms of how your brain ponders your future self, this notion of a negotiation between the present self and the future self perfectly matches this brain imaging data. It’s as if the brain, at a very fundamental level, thinks of the future you as someone else, rather than as the person whom you’ll become.
Temporal Discounting Test
The participants in this study also completed a temporal discounting test. Temporal discounting refers to the human tendency to disregard rewards the farther off they are in the future.
In the study, participants were offered various pairs of rewards and asked to select one. The rewards varied in size between $10 and $30.
They also varied in terms of delay between immediate reward with no delay and several months of delay. Based on many of these preference judgments, the experimenters could infer a monthly temporal discounting rate for each participant.
Given the choice of $10 right now or some larger amount after 30 days, what larger amount would result in an equal preference for the two?
For the average participant, this value was $14.27. Given a choice between $10 right now and $14.27 in 30 days, participants would choose each one about 50 percent of the time. However, this monthly discounting rate varied a great deal across participants.
For one participant, it was as low as $10. That is, he didn’t care if he received his $10 now or in 30 days. For some participants, it was as high as $25. They wanted $25 if they were going to be forced to wait 30 days to get it.
An interesting pattern emerges when you look at the brains of people with low and high temporal discounting rates. Some participants were so patient that they were willing to wait a month for even a small increase in the reward.
They showed much smaller reductions in the VMPFC activity when they shifted from thinking about their enjoyment of present and future tasks. The impatient participants were those who were only willing to wait 30 days if the monetary reward was much greater. This impatient group showed very large reductions in VMPFC activity.
The data implies that when patient participants thought about their future selves versus their present selves, their brains treated them very much the same. Conversely, the brains of the impatient people thought about their future selves in much the same way they thought about strangers whom they only knew by seeing a photograph. This explains why some people disregard the consequences of their actions.
This article was edited by Kate Findley, Writer for Wondrium Daily, and proofread by Angela Shoemaker, Proofreader and Copy Editor for Wondrium Daily.
Peter M. Vishton is an Associate Professor of Psychology at William & Mary. He earned his PhD in Psychology and Cognitive Science from Cornell University. Before joining the faculty of William & Mary, he taught at Northwestern University and served as the program director for developmental and learning sciences at the National Science Foundation.