We've all been there. You're staring at the breakfast table to start your day. You have two choices in front of you: the delicious chocolate doughnut, or the bowl of fruit. You really want that doughnut, but you know the fruit is healthier for you.
It's almost as if you're at war with yourself. The angel of our better selves whispers in one ear, while the demon of our secret desires whispers in the other. But that can't be possible, can it?
Yes, as it turns out, not only is it possible, it's likely. You can be at war with yourself. And it really is a bit like the good angel sitting on one shoulder, offering advice, while the bad angel tries to convince us to make different, less healthy choices.
In a startling new study published recently in the Journal of Neuroscience, researchers from the California Institute of Technology found that there are actually completely different neural processes at work whenever we struggle with ourselves over value choices like this.
In order to make the healthy choice—the bowl of fruit, in this instance—we often go through a value choice struggle internally. And the Caltech scientists have identified the neural processes at work during this sort of "self regulation"—basically, the different neural processes at work that determine whether you ultimately choose the doughnut or the bowl of fruit.
"We seem to have independent systems capable of guiding our decisions," said Cendri Hutcherson, the lead author on the Journal of Neuroscience paper about these competing brain systems. "And…these systems may compete for control of what we do."
The Caltech research builds on a large body of evidence showing that we routinely assign different values to options in front of us when we make decisions. For instance, do you put your child's car seat in the back seat—where it's safer, but more difficult to reach from the driver's seat—or in the front seat?
If you chose the back seat, it's likely because you assigned far greater value to safety than your own comfort, previous research has shown. People select the choice with the highest value.
"An important and controversial open question—which this study was designed to address—is whether there is a single value signal in the brain, or if there are instead multiple value signals with different properties that compete for the control of behavior," said Antonio Rangel, a Caltech economics and neuroscience professor and senior author of the paper.
If we had just one value system that our brain processes, we'd assign different, noncompeting values—like healthiness, taste, texture, etc.—to our selection of that chocolate doughnut at the breakfast table. Under this single-value hypothesis, we compare the different values together and that determines our ability to say "no" or "yes" to the chocolate doughnut.
But, it turns out, our brain doesn't work that way. The Caltech researchers found that there isn't a single system that assigns values in one, smooth decision-making system internally. There are, in fact, different neural systems that process different values.
The Caltech researchers set out to study and identify some of these different neural pathways as we make decisions. They found that there are, in fact, different sets of neurons literally at war with each other as we struggle internally to make decisions.
In short, our ability to choose the bowl of fruit over the chocolate doughnut depends entirely on whether the neurons and pathways in our brain are able to activate one value system over another as we make the choice.
So, if you place a higher value on health and you either choose (or train your brain) to select that value system, then you're going to select the bowl of fruit at breakfast. Your brain's neural processes choose the value path you've selected over another, competing pathway like taste.
"In many cases, these systems guide behavior in the same direction, so there's no conflict between them," said Hutcherson, a Caltech postdoctoral researcher. "But in other cases…they can guide behavior toward different outcomes. Furthermore, the outcome of the decision seems to depend on which of the two systems takes control of behavior."
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In the study, the researchers presented people with different food value choices under three different, competing conditions—suppressing a desire to eat food, increasing their desire or simply acting normally—and then mapped neural processes in two regions of the brain as they made them using a functional magnetic resonance imaging machine.
The researchers found that neural activity in two different brain areas—the dorsolateral prefrontal cortex, which sits behind the temples, and the ventromedial prefrontal cortex, which is just above our eyes—correlated closely with how much the study participants indicated they wanted particular food items like chips or healthy vegetables.
What's more, the researchers found that the two different regions of the brain played vastly different roles in our own, internal self-regulation process. The dorsolateral region (behind the temples) took control when the participants told themselves they did not want food. But when they encouraged themselves to desire food, the ventromedial region (above our eyes) took control.
There was also some lag time between the brain's ability to switch between the two regions, the researchers found. When a study participant tried to suppress a craving for a certain type of food, for instance, one region initially seemed to take control and drive behavior, but then flipped several seconds later to a second region of the brain as the participant actually curbed their appetite.
"This research suggests a reason why it feels so difficult to control your behavior," Hutchison said. "You've got these really fast signals that say, go for the tempting food. But only after you start to go for it are you able to catch yourself and say, no, I don't want this."
If the research holds as others study the multiple-value hypothesis, it may lead to some interesting conclusions—namely, whether you can improve your self control with more practice. You may, in fact, be able to train yourself to reach up and just swat that bad angel off your shoulder.