The poem “Maud Muller” by John Greenleaf Whittier aptly ends with the line, “For of all sad words of tongue or pen, The saddest are these: ‘It might have been!’” What if you had gone for the risky investment that you later found out made someone else rich, or if you had had the guts to ask that certain someone to marry you? Certainly, we’ve all had instances in our lives where hindsight makes us regret not sticking our neck out a bit more.

But new research suggests that when we are older these kinds of ‘if only!’ thoughts about the choices we made may not be so good for our mental health. One of the most important determinants of our emotional well being in our golden years might be whether we learn to stop worrying about what might have been.

 In a new paper published in Science, researchers from the University Medical Center Hamburg-Eppendorf in Hamburg, Germany, report evidence from two experiments which suggest that one key to aging well might involve learning to let go of regrets about missed opportunities. Stafanie Brassen and her colleagues looked at how healthy young participants (mean age: 25.4 years), healthy older participants (65.8 years), and older participants who had developed depression for the first time later in life (65.6 years) dealt with regret, and found that the young and older depressed patients seemed to hold on to regrets about missed opportunities while the healthy older participants seemed to let them go.

To measure regret over missed opportunities, the researchers adapted an established risk taking task into a clever game in which the participants looked at eight wooden boxes lined up in a row on a computer screen and could choose to reveal the contents of the boxes one at a time, from left to right. Seven of the boxes had gold in them, which the participants would earn if they chose to open them. One box, however, had a devil in it. What happens if they open the box with the devil in it? They lose that round and any gold they earned so far with it.

Importantly, the participants could choose to cash out early and keep any gold they earned up to that point. Doing this would reveal the location of the devil and coincidently all of the gold they missed out on. Sometimes this wouldn’t be a big deal, because the devil would be in the next box. No harm, no foul.  But sometimes the devil might be several boxes away. In this case, you might have missed out on a lot of potential earnings, and this had the potential to induce feelings of regret.

In their first experiment, Brassen and colleagues had all of the participants play this ‘devil game’ during a functional magnetic resonance (fMRI) brain scan.  They wanted to test whether young participants, older depressed, and healthy older participants responded differently to missed opportunities during the game, and whether these differences might also be reflected in activity in one area of the brain called the ventral striatum (an area known to very active when we experience regret) and another area of the brain called the anterior cingulate (an area known to be active when controlling our emotions). 

Brassen and her colleagues found that for healthy older participants, the area of the brain which is usually active during the experience of regret, the ventral striatum, was much less active during rounds of the game where they missed out on a lot of money, suggesting that the healthily aging brains were not processing regret in the same way the young and depressed older brains were. Also, when they looked at the emotion controlling center of the brain, the anterior cingulate, the researchers found that this area was much more active in the healthy older participants than the other two groups. Interestingly, Brassen and her colleagues found that the bigger the missed opportunity, the greater the activity in this area for healthy older participants, which suggests that their brains were actively mitigating their experience of regret.

In a second experiment, this time only including the older participants, Brassen and her colleagues measured the skin conductance and heart rate—two measures known to fluctuate with emotions—of the participants while they played the devil game. In light of the brain imaging findings demonstrating similarities between the healthy young and depressed older participants in response to missed opportunities, Brassen and her colleagues expected that if healthy older participants were actually letting go of regret, then their heart rates and skin conductance shouldn’t change during missed opportunities either. Indeed, they found that when the depressed older participants missed out on a bunch of money, their skin conductance and heart rate significantly decreased, whereas when the healthy older participants missed out on a bunch of money their skin conductance and heart rates remained constant.

In both experiments, there were also differences in the way participants played the devil game. While the older depressed and younger participants tended to react to missing out on a lot of money on one round by being riskier and opening more boxes on the next round, the healthy older participants kept the same strategy regardless. The authors propose that their findings reflect how the aging brain protects us from the negative feelings of regret that usually accompany missed opportunities.

But why would this be unique to the aging brain? Wouldn’t this also be important when we are younger? Knowing about research demonstrating how bad stress and negative emotions are for one’s physical health and life expectancy, I am sure any young person out there who turned down investing in the iPhone application Instagram before Facebook bought it for a billion dollars would like to let go of the regret they are experiencing right now.

Perhaps it might be better for us to feel the pain of such missed opportunities when we are younger so that we learn from them and make better choices in the future.  But when we are older, the future gets smaller, and so do the opportunities to correct previous missteps.  So, as we age a more effective strategy is to let go of the things we’ll have little opportunity to fix. For those who haven’t adopted this adaptive strategy towards missed opportunities, learning to do so may help improve their emotional well-being. Brassen and her colleagues suggest that their findings could be applied to an age-appropriate cognitive-behavioral therapy regimen that would help the unsuccessfully aging disengage from regret inducing experiences. Indeed, with the number of depressed people over the age of 65 estimated to be at roughly 6 million in the United States alone, it is encouraging to consider how this research might be used to improve their lives.

Are you a scientist who specializes in neuroscience, cognitive science, or psychology? And have you read a recent peer-reviewed paper that you would like to write about? Please send suggestions to Mind Matters editor Gareth Cook, a Pulitzer prize-winning journalist at the Boston Globe. He can be reached at garethideas AT or Twitter @garethideas.