The lure of instant gratification is hard to resist: when we want something, we want it right now. Of course, maturity and reality demand that we learn to wait, that we postpone our pleasures until tomorrow and tomorrow and tomorrow. And so we stash money in our savings account, and forgo the SUV for the sake of climate change and don’t eat the entire pint of ice cream. We resist the tug of immediate delight for the sake of even more delight in the future.
That, at least, is how we’re supposed to behave. The problems arise with a mental process known as delay discounting, which refers to our tendency to discount the value of a future reward as a function of its temporal distance. (Rewards that are farther away are discounted more heavily.) Consider this experiment led by Samuel McClure and Jonathan Cohen, which involved putting people in an fMRI machine and making them decide between a small Amazon gift certificate that they could have right away, or a slightly larger gift certificate that they’d receive in 2 to 4 weeks. Cohen discovered that these two options activated very different neural systems. When subjects contemplated gift certificates in the distant future, brain areas associated with rational planning, like the medial prefrontal cortex, were more active. These cortical regions urge us to be patient, to wait a few extra weeks for the bigger gain.
On the other hand, when subjects started thinking about getting a gift certificate right away, brain areas associated with emotion⎯like the midbrain dopamine system and nucleus accumbens⎯were turned on. These are the cells that tell us to take out a mortgage we can’t afford, or run up credit card debt when we should be saving for retirement. All they want is a reward, and they want it now.
By manipulating the amount of money on offer in each situation, Cohen and his collaborators could watch this neural tug of war unfold. Our ultimate decision – to save for the future or to indulge in the present – was largely determined by whichever region showed greater activation. The people who couldn’t wait for the bigger gift certificate were led astray by their feelings. More emotions meant more impulsivity. (This also helps explain why showing men revealing pictures of attractive women, or what scientists refer to as “reproductively salient stimuli,” makes men even more impulsive: the photos potentiate their emotional circuits.) On the other hand, subjects who chose the larger Amazon gift certificate showed increased activity in the prefrontal cortex, which allowed them to do the math and select the “rational” option.
A brand new study by neuroscientists at the University Medical Center Hamburg-Eppendorf helped extend these results, revealing the brain systems that allow us to forgo instant gratification at a much more precise level. The experiment was straightforward: subject were given a variety of different reward magnitude, from 20 to 35 euros, and a reward delivery time (immediately, 30 days, or 45 days). So far, so predictable: this is a standard delay discounting paradigm. But here’s where this experiment gets interesting: in half of these trials, the reward option was presented along with an ”episodic cue” derived from a previous “prescan” interview. The scientists asked the subjects about their future plans, focusing on events that coincided with the arrival of the reward. (In other words, they wanted to know what people were doing 30-45 days in the future.) Here’s where the results get interesting: when people were cued to think about personal future events, they were less likely to engage in delay discounting when making decisions about the monetary rewards. In other words, they exerted more self-control, with a reduction in reward discounting paralleling the vividness of their imagined future events.
Because all this future thinking was taking place in an fMRI machine, the scientists were able to glimpse the anatomy underling our ability to think about the future. When people imagined future events, there was an intricate “functional coupling” between parts of the prefrontal cortex, the anterior cingulate cortex and the hippocampus. The unexpected result here is the consistent activation of the hippocampus, a brain area synonymous with the formation of long-term memory. Why, then, is it also active when we’re thinking about the future? Moshe Bar, in an illuminating commentary in Neuron, speculates:
Is the hippocampus directly involved in future-oriented processes, or is it instead active in such processes because foresight relies on memory? The conclusion may be that none of these networks–decision making, predictions, and memory–is truly independent and their function cannot be distinguished from each other’s: memory provides the basis for predictions, and predictions provide the basis for decision making.
I’ve said it before, and I’ll say it again: the brain is the ultimate category buster. It takes all of our familiar distinctions – such as the clear divide between past and present, memory and foresight – and breaks down the divide. The end result is that a cortical fold specialized for the storing of the past is also recruited when we imagine an event 45 days in the future.
Needless to say, this data has many practical implications. For starters, it provides us with yet another tool in our cognitive kit when it comes to delaying gratification. While most techniques for fighting off errant impulses focus on reducing our emotional attraction to the reward – that’s why, for instance, Walter Mischel teaches kids to draw a picture frame around the marshmallow – this new research suggests that an even more effective approach involves activating vivid, episodic associations about future events. In other words, before we decide whether or not to make a big purchase, or take out a mortgage, or make a donation to a 401(k), or contemplate a policy devoted to climate change, we should spend a few minutes thinking about what we’re doing tomorrow. Interestingly, these associations don’t need to have any connection to the decision in question – it’s enough to simply contemplate the future. One possible explanation for this effect is that activating our “future-oriented processing” helps make the future seem more tangible and real. As a result, we’re better able to shrug off the visceral emotional pull of immediate rewards. We can’t always get what we want, but if we think about the future first, sometimes we can get what we need.