“For a long time, scientists used to believe the mammalian cerebral cortex to be the anatomical cause of cognitive ability,” coauthor Sara Letzner of Ruhr-Universität Bochum says in a press release. But birds have no cortex. “That means the structure of the mammalian cortex cannot be decisive for complex cognitive functions such as multitasking.”
Instead, pigeons have a brain region known as the pallium, which, while it doesn’t have the layered structure of the human cortex, does have a high density of neurons—with about six times more cells per cubic millimeter than the human brain. This means that pigeon neurons are about 50 percent closer together than human neurons, which may allow for electrical signals to be relayed at a faster rate.
In this study, published this week (September 25) in Current Biology, the researchers asked both birds and humans to switch the nature of the task they were performing. For humans, this involved pushing buttons when they saw certain patterns on a screen. Pigeons were trained to peck at particular buttons based on light signals.
When the signal to commence the second task came at the same time as the signal to stop the first task, both bird and human participants were able to switch with about the same speed. But when there was a short, 300-millisecond delay between the signal to stop the first task and the signal to start the second, the birds performed better than the human volunteers, with response times about 200 ms faster.