Welcome toSciam.com's "seminar blog" on the sciences of mind and brain. Each week, top researchers in neuroscience, psychology, and psychiatry explain and discuss the research driving their fields. Readers can join them. We hope you will.
In combing the scientific literature for papers to cover here, we inevitably see certain trends worth noting. This week we take a break from expert reviews to give a sampling of some notable papers and oddities having to do with one trend we've enjoyed tracking -- a fascinating array of papers showing surprising levels of animal savvy, learning, and understanding. The gap 'tween us and animals, it seems, grows e'er more narrow. Below are some of the more arresting examples. Readers are encouraged to provide more via the blue Comments link at bottom.
Two cichlids: at top a nondominant male without territory, and at bottom a dominant male with territory. Researchers at the Fernald Lab at Stanford found that removing the dominant fish created a genetic cascade in the nondominant fish that turned him from Rick Moranis to Arnold Schwarzenegger in just hours. Photo courtesy Fernald Lab and Stanford News Service.
Socially Savvy Cichlids While on the West Coast last week I had a chance to chat with Stanford researcher Russell Fernald, whose studies of the African cichlid fish Haplochromis burtoni have produced a number of startling insights. Fernald's most recent splash was with a paper we may cover yet in Mind Matters, "Fish can infer social rank by observation alone" (Nature. 1 Mar 2007). The paper describes how cichlids use a social-cognition skill known as "transitive inference," which essentially allows you to recognize the pecking order in surrounding social systems. As the abstract puts it,
Transitive inference (TI) involves using known relationships to deduce unknown ones (for example, using A > B and B > C to infer A > C), and is thus essential to logical reasoning. First described as a developmental milestone in children, TI has since been reported in nonhuman primates, rats and birds. Still, how animals acquire and represent transitive relationships and why such abilities might have evolved remain open problems. Here we show that male fish (Astatotilapia burtoni) can successfully make inferences on a hierarchy implied by pairwise fights between rival males. These fish learned the implied hierarchy vicariously (as 'bystanders'), by watching fights between rivals arranged around them in separate tank units.You can learn more via a Stanford news service story, the paper itself (if you've Nature access, or through a pdf download at the Fernald lab's website.
Rick Moranis to Arnold Schwarzenegger -- Overnight Fernald's lab also produced one of the most dramatic findings I've seen lately from either social or genetic studies: a October 2005 study that found almost instant transformation that subdominant male cichlids undergo when the dominant male in their vicinity is removed. Fernald found that a change in social status -- that is, the removal of the top-dog fish -- created a startling genetic response in the next-to-top-dog cichlid that would in just 3 days double the fish's size, double the size of its gonads, and change its color from nondescript silver to a dom-looking greenish black. The fish essentially changes from Rick Moranis to Arnold Schwarzenegger in three days, and the genetic transformation begins almost immediately. (For more, see the Stanford news story or the original paper at PLOS Biology.)
Rats that reason, jays that plan -- and a parrot that can putt and dunk Our roundup of prominent blips on the smart-animal radar would not be complete without a nod to jays that plan their food caches according to expected levels of hunger and food supply monkeys who quickly learned to classify movements by surprisingly abstract patterns of movement rather than actual movement sequences. The jay finding defies the prevailing Bischof-Kohler hypothesis, which holds that only humans can dissociate themselves from current motivations and anticipate future needs. The monkey findings suggests a remarkably high level of abstraction taking place at early and fundamental stages of primate cognition -- in other word, that monkeys think more abstractly than generally thought (at least, more than generally thought by humans). Finally, while you're thinking about animals that think -- or at least learn well -- you'll want to check out this video of a parrot who has learned to putt and play basketball -- while he talks trash. I'm not making this up. Enjoy, comment if you wish -- and we'll see you next week.