New findings on animal memory
A new study shows that all animals have equally bad short term memory. The only species that stands out is man.
“When it comes to short-term memory, it seems to work almost the same for all animals. It's a bit surprising that apes do not remember better than rats, but the results are clear. Human memory stands out because it is so susceptible, anything seems to stick in the memory for a very long time,” says Johan Lind, associate Professor of ethology at Stockholm University.
100 memory experiments
Researchers at the Centre for the Study of Cultural Evolution at Stockholm University and Brooklyn College have conducted the study, a meta-analysis of nearly 100 memory experiments on 25 different species. The study shows that animals have different memory systems. Simply put, animals have short term memory and specialised memories. In short-term memory, animals store information about almost anything but the information disappears quickly. Animals also have a variety of specialised memories that, on the one hand, can only store a certain type of information, but on the other hand, the information is stored for a very long time.
Short term memory and specialised memories
As an example, one can take a hoarding crow bird that remembers the location of the hidden nuts for months, but the animals have trouble remembering other things in other contexts for even a minute. Specialised memories hold information for a long time, consider for example that animals can remember other individuals, places rich in food, or if certain foods are toxic, for very long time periods. However, memories of events that trigger these specific systems disappear in a matter of seconds or a few minutes. “This seems to apply to all animals except man,” says Magnus Enqvist, Professor of Ethology at Stockholm University.
Sometime in our prehistory, we developed mental abilities that enabled people to speak, learn to read and build complex societies.
“Our study helps to better understand how human psychology changed over the past millions of years,” says Stefano Ghirlanda, a professor of psychology at Brooklyn College.
This is how the experiments were made
The experiments were analysed, using so-called delayed-matching-to-sample tests, examining short-term memory and starts with an animal may see a stimulus, such as a red dot. The red dot disappears, and after some time the animal may see two stimuli, one of which is the same as the first, while the other is different, for example a black square. The animal is rewarded if it chooses the same stimulus after the break as it saw before the break, in this case the red dot.
February 6, 2015
Source: External Relations and Communications Office