(NaturalNews) A complex thought process previously believed to exist only in humans has been discovered in rats, according to a new study published in the journal Nature Neuroscience. Researchers from Minnesota University observed for the first time that rats are capable of feeling regret over their decisions much like humans, showing a level of consciousness never before seen in mammals other than humans, let alone in rodents.
Professor David Redish and his colleagues constructed a test which they dubbed "Restaurant Row" that presented test rats with multiple options for obtaining food. One of the restaurants served high-quality food that required more waiting time to access, while another restaurant served lesser-quality food that was available much sooner, satisfying the innate desire for instant gratification.
When given these two options, some of the rats waited for a while at the nicer restaurant, only to become frustrated and resort to the quicker restaurant. When the rats discovered that the food at the second restaurant was not as desirable as the food served at the first, some of them stopped and looked back, expressing unique brain activity that clearly indicated feelings of regret.
"It's like waiting in line at the restaurant," explained Redish to BBC Nature. "If the line is too long at the Chinese restaurant, then you give up and go to the Indian restaurant across the street."
Regret is much more complex than simple disappointment, and rats experience it
At first glance, the rats' decision to look back and consider the first restaurant option could have been just disappointment with having chosen the lesser of the two food options. But upon closer analysis, the team discovered that key areas of the brain associated with regret -- that is, a literal feeling of sorrow or disappointment over having made what is perceived to be a wrong choice -- had been activated.
"Regret is the recognition that you made a mistake, that if you had done something else, you would have been better off," added Redish. "The hard part was that we had to separate disappointment, which is just when things aren't as good as you hoped. The key was letting the rats choose."
How they determined this was by looking at the rats' orbitofrontal cortex, an area of the brain also found in humans. When regret is felt, this area of the brain is activated. And in the rats, this area was clearly demonstrative of regret over their decision, not simply a sense of loss over having missed out on the preferable reward.
"Interestingly, the rat's orbitofrontal cortex represented what the rat should have done, not the missed reward," stated Redish. "This makes sense because you don't regret the thing you didn't get -- you regret the thing you didn't do."
Animals are much smarter than previously thought, suggests research
The research brings to light an exceptional level of consciousness among some mammals that has previously gone unnoticed by science. Perhaps with the exception of apes and monkeys, no other mammalian group has been identified as possessing this level of advanced cognizance, which proves that there is still so much that we don't know about how the world works.
"Disappointment entails the recognition that one did not get the value expected," explains the study. "In contrast, regret entails recognition that an alternative (counterfactual) action would have produced a more valued outcome."