When it comes to multitasking, pigeons are sometimes faster than humans
Multitasking is considered to be particularly demanding cognitively. However, not only the complex cerebral cortex of mammals can cope with this task, but small bird brains are completely sufficient, according to the results of a current study by scientists from the Ruhr University Bochum (RUB) and the University Hospital Carl Gustav Carus at the Technical University Dresden. In some respects, pigeons even performed better in multitasking than humans.
According to the researchers' results, pigeons can switch between tasks as quickly as humans. In some situations, they are even faster. This clearly proves that multitasking does not require the complex cerebral cortex of mammals, as has long been assumed. Dr. Dr. Sara Letzner and Professor Dr. Dr. H. c. Onur Güntürkun from the RUB and Dr. Christian Beste from the University Hospital Carl Gustav Carus published in the journal "Current Biology".
Complex cerebral cortex is not required
In behavioral experiments, the researchers had both humans and pigeons stop an action in progress and switch to an alternative action as quickly as possible to test their ability to multitask. For a long time it was believed that the six-layered cerebral cortex of mammals was the anatomical origin of cognitive abilities, reports Dr. Letzner. However, such a structure does not occur in birds, so that “the structure of the mammalian cortex cannot be the prerequisite for complex cognitive functions such as multitasking,” explains the researcher in a RUB communication.
Less distance between the neurons
The birds' brain mantle, the pallium, does not have any layers comparable to the human cortex, but the neurons here are more densely packed than in the human cerebral cortex, the researchers report. For example, per cubic millimeter of brain there are six times more nerve cells in pigeons than in humans. As a result, the average distance between two neurons in pigeons is only around half the average distance between human neurons.
Can bird brain process information faster?
Based on the shorter distance between the neurons and the fact that nerve cell signals in birds and mammals are transmitted at the same speed, the researchers hypothesized that information can be processed faster in the avian brain than in mammals. They checked this using the tests, in which pigeons and humans had to switch between two tasks - either immediately or after a short delay.
Humans and pigeons tested
Fifteen people and twelve pigeons completed the multitasking task, in which they had to stop an action in progress and switch to an alternative action as quickly as possible. "The change to the alternative action took place either simultaneously with the stopping of the first action or with a short delay of 300 milliseconds"; explain the scientists.
No difference in real multitasking
According to the researchers, if there is an immediate change to the new task, real multitasking takes place because two processes take place in parallel in the brain - stopping the first action and switching to the alternative action. In the case of pigeons and humans, this had equally slowed their activity due to the double exposure.
Bird brain faster with alternate processing
According to the researchers, if the change between the tasks took place after a short delay, the processes in the brain changed. Here, between the two processes, i.e. stopping the first action and switching to the second action, an alternating processing as in a ping-pong game can be determined. For this, it is necessary to continuously send signals back and forth between the groups of nerve cells that control the two processes. The pigeons were actually a bit more efficient in this experiment. They were 250 milliseconds faster than humans. The scientists attribute this to the fact that the pigeons have an advantage here due to the greater density of the nerve cells.
According to Dr. Letzner has “it has long been a mystery in cognitive neuroscience how birds with such small brains and without a cortex can be so smart that some of them, such as crows and parrots, can cognitively take on chimpanzees.” Here the results can According to the experts, the current study provides at least a partial answer. Because of the small but densely packed brain, birds are able to reduce the processing times for tasks that require a fast interaction between groups of neurons. (fp)