Can monkeys choose optimally when faced with noisy stimuli and unequal rewards?

Feb 13, 2009

Even when faced with distractions, monkeys are able to consistently choose the path of greatest reward, according to a study conducted by researchers from Princeton and Stanford Universities.

The study, published February 13th in the open-access journal PLoS Computational Biology, adds to the growing evidence that animal foraging behavior can approach optimality, and could provide a basis for understanding the computations involved in this and related tasks.

In the article, Feng and colleagues address ongoing experiments relating to monkeys' abilities to distinguish among moving stimuli. Monkeys were trained to identify the direction of motion of a field of randomly-moving dots, a fraction of which move coherently in one of two possible directions. But unlike most previous studies in which all correct choices were equally rewarded, different sized rewards were now associated with different stimuli, and the researchers 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. The study is unique in that it assesses not only the accuracy of decisions, but also the overall harvesting efficiency.

Remarkably, 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 1-2% of the theoretical maximum. These findings reveal impressive decision-making ability, and raise important questions about the neural mechanisms that underlie it.

More information: Feng S, Holmes P, Rorie A, Newsome WT (2009) Can Monkeys Choose Optimally When Faced with Noisy Stimuli and Unequal Rewards? PLoS Comput Biol 5(2): e1000284. doi:10.1371/journal.pcbi.1000284 dx.plos.org/10.1371/journal.pcbi.1000284

Source: Public Library of Science

Explore further: Biologist reels in data to predict snook production

add to favorites email to friend print save as pdf

Related Stories

Is Australia's claim to Antarctica at risk?

1 minute ago

While Australia's commitment to a 20-year plan for Antarctica has been welcomed by some it has also raised concerns over the nation's ability to fulfil a credible research role in the south polar region.

Recommended for you

Crowdsourced power to solve microbe mysteries

52 minutes ago

University of New South Wales scientists hope to unlock the secrets of millions of marine microbes from waters as far apart as Sydney's Botany Bay and the Amazon River in Brazil, with the help of an international ...

Pigeons and people play the odds when rewards are higher

1 hour ago

(Phys.org) —If you were weighing the risks, would you choose to receive a guaranteed $100, or take a 50/50 chance of winning either $200 or nothing? Researchers at the University of Alberta have shown that ...

Team advances genome editing technique

18 hours ago

Customized genome editing – the ability to edit desired DNA sequences to add, delete, activate or suppress specific genes – has major potential for application in medicine, biotechnology, food and agriculture.

User comments : 0