Monkeys are adept at choosing greatest reward even while faced with distractions

Washington, February 13 (ANI): A group of researchers from Princeton and Stanford Universities have found that monkeys can consistently choose the path of greatest reward, even when they are distracted.

Revealing their findings in the open-access journal PLoS Computational Biology, the researchers said that their findings added to the growing evidence that animal foraging behaviour could approach optimality, and provide a basis for understanding the computations involved in this and related tasks.

In their study report, the researchers have revealed that they trained monkeys to identify the direction of motion of a field of randomly-moving dots, a fraction of which moved coherently in one of two possible directions.

However, unlike most previous experiments that had all correct choices equally rewarded, different sized rewards were associated with different stimuli in the current study.

The researchers said that they developed a mathematical model to predict how the animals should balance sensory information and prior expectations regarding rewards, in order to maximize their net returns.

According to them, their study is unique because it assesses not only the accuracy of decisions, but also the overall harvesting efficiency.

The research team observed that the monkeys devised a near-optimal strategy.

Across the course of several hundred choices in each daily session, with randomly interspersed coherence and reward conditions, their typical harvesting efficiency fell within one to two per cent of the theoretical maximum.

The researchers said that their findings demonstrated impressive decision-making ability, and raised important questions about the neural mechanisms that underlie it. (ANI)