A new study has uncovered evidence that rats feel regret, a discovery that is significant to both the idea of animal sentience and our understanding of neuroanatomy (rodent and otherwise). As the abstract puts it:
In humans, the orbitofrontal cortex is active during expressions of regret, and humans with damage to the orbitofrontal cortex do not express regret. In rats and nonhuman primates, both the orbitofrontal cortex and the ventral striatum have been implicated in reward computations … In [what rats would regard as regrettable] situations, rats looked backwards toward the lost option [and] cells within orbitofrontal cortex and ventral striatum represented the missed action...
Scientific American’s Fikri Birey observed something else about this experiment—something that may tell us a little bit about the human experience, and provide insight into the psychology of addiction (including, but not limited to, gambling addiction):
Studies of regret in humans show that people regret miscalculated actions more than the missed outcomes … When compared to the activity signatures at the moment of regret (based on when a rat turned and looked at the missed opportunity), it was the signature of zone, not of the regret, that lit up in the respective brain regions: Rats regret having skipped the zone more than having not received the reward.
This suggests that Benjamin Franklin may have been on to something when he used a sophisticated habit-tracking system to modify his own behavior. By consciously regretting his own failure to adopt good habits or abandon bad ones, Franklin may have helped to nudge his own neurochemistry towards correct attributions of regret (“My stomach hurts because I ate too much”) and away from incorrect attributions of regret (“My stomach hurts because I did not pray hard enough”).
And because there is now evidence that even rats learn from regret, it becomes especially important that we learn to regret the right things. This is easier said than done—it has been the subject of five thousand years of moral philosophy—but this study, and similar studies on the human psychology of regret, may ultimately make us more benevolent, and ultimately happier, people.