AdvAnces

cognition If the jays were capable of metacogni­ tion, Watanabe surmised, the birds should The Thinker realize that they could easily find the second Evidence suggests that humans researcher’s food. The wax worm had to be are not the only animals in the singular open cup. They should instead capable of introspection prefer keeping their eyes on the setup with four open cups because witnessing where When you do not know the answer to a that food went would prove more useful in question, say, a crossword puzzle hint, you “stuck in time”—that is, they are able to re ­ the future. And that is exactly what hap­ realize your shortcomings and devise a member past events and are known to cache pened: the jays spent more time watching strategy for finding the missing information. their food in anticipation of hunger, according the first researcher. The results appeared in The ability to identify the state of your to psychologist Arii Watanabe of the Univer­ the July issue of the journal Animal Cognition. knowledge—thinking about thinking—is sity of Cambridge. But the question remained: Friederike Hillemann, who studies cor­ known as metacognition. It is hard to tell Are they aware that they are planning? vids at the University of Göttingen in Germa­ whether other animals are also capable of Watanabe devised a way to test them. ny, thinks the experiment is an elegant way metacognition because we cannot ask He let five birds watch two researchers to determine whether animals are capable of them; studies of primates and birds have hide food, in this case a wax worm. The reasoning about their own knowledge states. not yet been able to rule out simpler expla­ first researcher could hide the food in any of Although this experiment did not di rectly nations for this complex process. four cups lined up in front of him. The sec­ test consciousness, the findings are ex citing Scientists know, however, that some ani­ ond had three covered cups, so he could because they provide further evidence that mals, such as western scrub jays, can plan for place the food only in the open one. The humans are not the only species with the the future. Western scrub jays, corvids native trick was that the researchers hid their food ability to think about their thought processes. Images Getty to western North America, are a favorite of at the same time, forcing the birds to choose Or, as Watanabe put it, “some birds study for

cognitive scientists because they are not which one to watch. a test like humans do.” — Jason G. Goldman Sartore Joel

Introducing BRIEFINGS KNoW the Induced seismicity: a new collection of research JARGON summaries from Scientifi c American (n.) earthquakes caused by human activities. Not long ago earthquakes in Oklaho- enough water into the earth, you can ma were rare. Not anymore. Twenty influence the cycle of earthquakes.” earthquakes of 3.0 magnitude or great- After using hydrogeologic models er shook Oklahoma in 2009. The state with the seismic data, Keranen and her has seen a 40-fold increase in seismic- colleagues concluded that four disposal ity since 2008. The cause? Humans, wells southeast of Oklahoma City likely according to new research in Science. caused the Jones swarm, a group of The study confirmed what geologists earthquakes that accounted for 20 per- have been speculating for years: that cent of seismicity in the central and underground water disposal by oil and eastern U.S. between 2008 and 2013. Scientifi c American Briefi ngs brings you gas companies causes earthquakes. The team also found that wastewater up to speed with research highlights Millions of gallons of wastewater injection induced earthquakes as far as selected from peer-reviewed, professional are produced every month in Oklaho- 30 kilometers away from the wells, science journals. Get the scientifi c ma as a result of extracting oil and nat- much farther than previously thought. developments on the topics that matter most to you—simple, easy and fast. ural gas from the ground. The compa- Geologists have used the term nies inject this wastewater into wells to “induced seismicity” to describe earth- Download a FREE Issue! dispose of it, which raises the ground- quakes triggered by mining, dams, scientifi camerican.com/briefi ngs water pressure and can stress geologic underground nuclear tests and waste- faults. “Normally, earthquakes occur water injection. As oil and gas extrac- naturally because of plate motions,” tion methods become more common Subscription only. Monthly e-publications include: Climate Change & Environment, Health & Medicine, says Katie Keranen, a geophysics pro- and more studies connect their dispos- Mind & Brain, Nanotechnology, and Space & Physics. fessor at Cornell University and the al methods to seismic activity, the term study’s lead author. “But if you inject will be one to watch. —Annie Sneed

SAB_FreeIssue_1-6V.indd 1 2/11/12 2:01 PM 30 Scientific American, September 2014 Comment at ScientificAmerican.com/sep2014

0914Partials.inddsad0914Adva3p.indd 10 30 7/25/147/23/14 12:15 6:42 PM