THERE may come a day when you are beaten in a game of rock, paper, scissors by a monkey. You shouldn't be either ashamed or alarmed by this for several reasons.

The first is that they're being taught how to play the ultimate game of anticipation by people at Yale University who are very likely to be much cleverer than you.

The monkeys receive "large juice rewards" for winning, smaller rewards for tying and nothing for losing, and apparently they got the hang of it real quick.

So that's a great headstart. But you'd get pretty handy at rock, paper, scissors quickly too, if someone gave you $10 every time you beat them.

The other reason you'd needn't worry is that the monkeys only showed the capacity to copy the previous winning move.

If a monkey threw paper and its opponent threw scissors — then smugly downed its large juice reward — the paper-thrower would tend to choose scissors in the next round.

So as long as you have the capacity to remember the winning throw from one game to the next, you're still a chance to beat the monkey.

The bit that the Yale researchers were most interested in, however, was the losing monkeys' ability to feel regret over the fact that they missed out on juicy goodness.

Until now, humans have been thought to have had a monopoly on regret, believing it to be a unique trait that prevents us from repeating bad decisions, aka throwing paper seven times in a row.

Essentially, it is an ability that allows us to recognise that taking alternate courses of actions could have led to better outcomes.

The downside to regret it is can become debilitating if we obsess over it.

"Sometimes regret can be very damaging," Daeyeol Lee, professor of neurobiology at Yale School of Medicine and co-author of the study, said.

As can being beaten by a monkey at rock, paper, scissors.

But the real point of the monkey study — published in the May 26 issue of Neuron — was to find areas of the brain where this process of regret takes place, which may give scientists new clues into how to treat diseases such as depression and schizophrenia.

To measure it, the Yale team recorded neural activity in the rhesus monkeys playing rock, paper, scissors.

When the monkeys lost, they saw an increase in neural activity in the prefrontal cortex of their brains. That area also contains a subdivision that has previously been linked to things like our working memories.

Hence neurons also found here signal what action would lead to a better outcome — the positive learning aspect of regret.

"Our brain is wired to run these hypothetical simulations all the time," Prof Lee said.

"If you try to learn only from the actual outcomes of your own experience, this represents only a tiny fraction of information you can get from your world."

Another subdivision is linked to the emotional aspects of regret — those which make the monkeys sad that they didn't get a large juice reward.

All of which means Prof Lee and his team aren't wasting time at all, because knowing the neural home of regret may help researchers find drugs to treat mental illnesses in which patients obsess over poor decisions.

And the monkeys finally have something proper and decent to do with their hands when they're bored.

