Pigeons better at multitasking than humans
These are the findings of biopsychologists who had performed the same behavioural experiments to test birds and humans.
The authors hypothesize that the cause of the slight multitasking advantage in birds is their higher neuronal density.
Dr Sara Letzner and Prof Dr Dr h. c. Onur Güntürkün from Ruhr-Universität Bochum published the results in the journal "Current Biology" in collaboration with Prof Dr Christian Beste from the University Hospital Carl Gustav Carus at Technische Universität Dresden.
"For a long time, scientists used to believe the mammalian cerebral cortex to be the anatomical cause of cognitive ability; it is made up of six cortical layers," says Sara Letzner. In birds, however, such a structure does not exist.
"That means the structure of the mammalian cortex cannot be decisive for complex cognitive functions such as multitasking," continues Letzner.
The pallium of birds does not have any layers comparable to those in the human cortex; but its neurons are more densely packed than in the cerebral cortex in humans: pigeons, for example, have six times as many nerve cells as humans per cubic millimetre of brain.
Consequently, the average distance between two neurons in pigeons is fifty per cent shorter than in humans.
As the speed at which nerve cell signals are transmitted is the same in both birds and mammals, researchers had assumed that information is processed more quickly in avian brains than in mammalian brains.
They tested this hypothesis using a multitasking exercise that was performed by 15 humans and 12 pigeons.
In the experiment, both the human and the avian participants had to stop a task in progress and switch over to an alternative task as quickly as possible.
The switchover to the alternative task was performed either at the same time the first task was stopped, or it was delayed by 300 milliseconds. ■