Why would respectable scientists spend their time figuring out what monkeys will pay to watch? As it turns out, the research may lead to a better understanding of human autism.
Monkeys put a price on attention. I'm Bob Hirshon and this is Science Update.
Monkeys may not have cable subscriptions, but they're happy to pay-per-view. That's according to Duke University neurobiologist Mike Platt.
He and his colleagues gave male monkeys fruit juice as a reward for looking at images. The monkeys would accept less juice when it was an image they wanted to see.
Our main findings were that monkeys would give up a significant amount of juice to see the hindquarters of female monkeys, as well as the faces of dominant individuals. But we had to pay them to look at the faces of subordinates.
Dr. Platt says the research could lead to better models of human autism. That's because autistic people aren't motivated to look at others and can't make social judgments. I'm Bob Hirshon for AAAS, the Science Society.
Making Sense of the Research
This study may seem far removed from the world of human medicine. But in fact, it shows how understanding the human body (or mind) requires a broad foundation of research.
We all make judgments about how to spend our attention. For example, we may consider the school principal more worthy of our attention than a classmate (or vice versa!). At a concert, we might pay more attention to the headliner than to the opening act. We might respond more strongly to someone in a uniform than someone in street clothes. We would probably pay closer attention to someone who was speaking directly to us than to a radio playing in the background.
People with autism lack this ability. They don't know how to make social judgments. As a result, they have difficulty interacting with other people. An autistic person might be more captivated by the static coming from a television than from a live person sitting on the couch with him or her.
To understand these social judgments, scientists would like to describe them in mathematical terms. That's why Platt's team conducted the monkey experiment. In their experiment, monkeys were given a carefully measured amount of juice when they looked at, or away from, various pictures. If the monkeys didn't care one way or another about the pictures, they would have just followed the juice—by looking at whatever pictures offered them the most juice.
However, it didn't turn out that way. The monkeys were willing to accept relatively little juice to look at socially important images, like dominant males or potential mates. But they had to be paid extra juice to look at submissive males. Therefore, Platt's team can now assign a value—an amount of juice—that certain social images are "worth."
Although it may be much more complicated, the same may be possible in people. And if scientists can measure human attention in a concrete way, it will be easier to study what exactly goes wrong in autism. It may also be possible to pinpoint the areas of the brain that malfunction in autistic patients, which could pave the way for better treatments.
Now try and answer these questions:
- What does this study have to do with autism?
- What does it mean to say that the monkeys "paid" to see certain images?
- Why do scientists need to put hard numbers on tricky concepts like social judgments and attention?
In the National Geographic News article "Hot Tub Monkeys" Offer Eye on Nonhuman "Culture," read about evidence of culture in non-human primates. And in Monkeys Show Sense of Fairness, read about another strikingly human aspect of the monkey mind.