Here's looking at you, fellow!

Mar 02, 2009
Monkeys and humans both look predominately at the eyes of conspecifics whereas they let their gaze wander over the whole face when presented with images of an individual of a different species. Image: Max Planck Institute for Biological Cybernetics/Christoph Dahl

(PhysOrg.com) -- Already Charles Darwin investigated facial expressions of monkeys in order to find out how closely related humans and monkeys really are. Scientists at the Max Planck Institute for Biological Cybernetics have now shown that rhesus monkeys and humans employ the same strategies to process faces of conspecifics: both species look first at the eyes of conspecifics, whereas for non-conspecific faces they let their gaze wander over the whole face.

This means that for both species during evolution the same perceptual mechanisms have developed in the brain. It must have therefore been adventitious also for our next of kin to process faces of conspecifics with a dedicated perceptual strategy. (Current Biology, February 26th, 2009)

In the study, faces of the two species were shown to both monkey and human observers while their eye movements were being recorded. The faces were presented both "normally" and upside-down. It is a well-known effect in perceptual psychology that upside-down faces are hard to recognize as the usual face processing mechanisms cease to work. In addition, we know that gaze is attracted to the eyes for "normally" shown faces. These two facts can therefore be used to uncover different processing strategies: many fixations on an eye region are a tell-tale sign of "normal" face processing.

The study has shown that this processing strategy in monkeys only holds for monkey faces, whereas in humans it only holds for human faces - even though the two species share rather similar facial features (eyes, nose, mouth). In addition, the recorded eye movements of both species were exactly the same for non-conspecific faces as for upside-down faces: in both cases fixations moved away from the eyes to other parts of the face.

Monkeys are therefore experts for monkey faces and humans experts for human faces. "The surprising finding is that in addition the perceptual strategies for processing conspecific faces are exactly the same. Humans and monkeys are therefore even more similar than previously thought," said Christoph Dahl, one of the two main authors of the study.

More information: Christoph D. Dahl, Christian Wallraven, Heinrich H. Bülthoff & Nikos K. Logothetis, Humans and macaques employ similar face-processing strategies, Current Biology (2009), doi:10.1016/j.cub.2009.01.061

Provided by Max-Planck-Institute for Biological Cybernetics

Explore further: Ideology prevents wheat growers from converting to more profitable methods, new study shows

add to favorites email to friend print save as pdf

Related Stories

People finding their 'waze' to once-hidden streets

1 hour ago

When the people whose houses hug the narrow warren of streets paralleling the busiest urban freeway in America began to see bumper-to-bumper traffic crawling by their homes a year or so ago, they were baffled.

Identity theft victims face months of hassle

1 hour ago

As soon as Mark Kim found out his personal information was compromised in a data breach at Target last year, the 36-year-old tech worker signed up for the retailer's free credit monitoring offer so he would ...

Observers slam 'lackluster' Lima climate deal

1 hour ago

A carbon-curbing deal struck in Lima on Sunday was a watered-down compromise where national intransigence threatened the goal of a pact to save Earth's climate system, green groups said.

Your info has been hacked. Now what do you do?

2 hours ago

Criminals stole personal information from tens of millions of Americans in data breaches this past year. Of those affected, one in three may become victims of identity theft, according to research firm Javelin. ...

New Bond script stolen in Sony hack

2 hours ago

An "early version" of the screenplay for the new James Bond film was the latest victim of a massive hacking attack on Sony Pictures Entertainment, its producers said in a statement on their website Sunday.

Ag-tech could change how the world eats

7 hours ago

Investors and entrepreneurs behind some of the world's newest industries have started to put their money and tech talents into farming - the world's oldest industry - with an audacious agenda: to make sure there is enough ...

Recommended for you

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.