Even rats think - about their own abilities. Photo: Dot Paul, University of Georgia
Reading aloud When rats get a task, they first evaluate whether they have enough information for the solution, an American researcher duo discovered. If this is not the case, the rodents are more likely to choose not to participate in the test, even though they will gain less than with a proper solution to the problem. As a result, rats are, according to previous knowledge, the only animals with the ability to think about their own thought processes and also to judge them. Metacognition call psychologists the ability to be aware of their own knowledge and thinking. It ensures, for example, that a student who is not well prepared feels very uncomfortable before taking an exam because he knows very well about his or her own knowledge gaps. Whether animals are able to do that is controversial among scientists? mainly because it is not possible to directly ask the animal subjects. The psychologists Allison Foote and Jonathon Crystal therefore now chose an indirect method already tested in primates to look for signs of metacognition in their rats: they allowed the animals to choose whether to take part in a test or not.

To do so, they first taught the rodents to distinguish long and short sounds. After this training, the rats were then presented with two alternatives: If they participated in the test and mastered the task, they received a great reward in the form of six pellets. If they were wrong in their answer, they received nothing. On the other hand, if they decided against taking part in the test from the start, they were given three pellets of food. During the individual test series, the degree of difficulty of the tasks increased more and more. If the eight-second and two-second sounds were very easy to distinguish at the beginning, the difference between them diminished more and more in the course of the experiments until the two sounds of 3.62 and 4.42 seconds in length closely resembled each other.

The harder the tasks became, the more the rats decided against taking part in the test, the researchers observed. If they were forced to do so, they provided far more false answers than during voluntary participation. This shows that the animals were able to assess whether they would be up to the task before the start of the test or not. Thus, the brain of a rat and possibly also of other animals have much more complex capabilities than previously thought, the researchers said. The results could now help to better understand thought processes in humans.

Allison Foote and Jonathon Crystal (University of Georgia, Athens): Current Biology, Online Pre-Release, DOI: 10.1016 / j.cub.2007.01.061 ddp / science.de? Ilka Lehnen-Beyel advertisement

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