Working memory is the brain’s ability to process information in a retrievable state for a short time. It is essential to performing complex cognitive tasks such as thinking, planning, following instructions, or solving problems. A team of researchers from the Ruhr University Bochum (RUB) has now succeeded in examining this special area of memory in birds more closely and comparing it with the data storage in the brain of mammals. The scientists found that birds and monkeys – despite their different brain architecture – share the same central mechanisms and limitations of working memory.
The researchers at the Chair for Neural Basics of Learning at the RUB published the results in the journal eLife on December 3, 2021.
Research on the bird’s brain complements existing models
The capacity of the working memory is limited. Humans can only take in about four pieces of information at the same time – and it is precisely this limitation that made the Bochum researchers curious. “There are various theories about how limitations arise in the brain and what role the network of neurons plays in this,” describes first author Lukas Hahn. “However, the existing models are based exclusively on studies on humans and other primates. We wanted to supplement these with our expertise. “
Hahn, who works in the department of Professor Jonas Rose at the Faculty of Psychology, specializes in researching the neural basis of cognition in the bird’s brain. “The working memory of some birds, such as crows, has a similar capacity to that of humans, although their brain architecture is very different from that of mammals,” says Jonas Rose, head of the Department of Neural Basics of Learning at RUB. “We wanted to know: How can brains with such clear structural differences produce working memories with similar abilities?”
Test design transferred from macaques to carrion crows
To do this, the Bochum scientists observed crows at the Faculty of Psychology in Bochum. They tested the birds’ working memory using an exercise originally developed for macaques. “We taught the crows to look at a screen and memorize different numbers of colored squares,” explains Hahn. “After a pause with a second of black screen, we presented them the squares on the screen again, but a little differently. The birds now had the task of finding out which square had changed.”
While the crows did the job, the scientists recorded neuron activity in an area of the brain that corresponds to the prefrontal cortex – the central center of cognition in mammals. “The studies showed that the neurons in the crow’s brain reacted to the changing colors in practically the same way as the neurons in monkeys,” analyzes Rose. In addition, the scientists found that increasing the number of elements the crows needed to remember changed the amount of information that encoded individual neurons to the same extent as was previously observed in monkeys.
The same mechanisms despite different brain architecture
Lukas Hahn: “The similarities between the distantly related bird and mammal species confirm already existing core ideas about the limits of working memory. In addition, they suggest that birds and monkeys, despite their different brain architecture, share the same core mechanisms and limits of working memory “That would be an exciting future question to uncover further neural bases of cognition in the bird’s brain.”
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