BOCHUM, Germany — If someone calls you a “bird brain,” consider it a compliment. It turns out that bird brains are better than human brains — when it comes to multitasking.
Researchers at Ruhr-University Bochum tested humans against pigeons in a multitasking matchup and found that the birds could switch between two tasks just as quickly — and sometimes more quickly — than people.
“For a long time, scientists used to believe the mammalian cerebral cortex to be the anatomical cause of cognitive ability,” says study co-author Dr. Sara Letzner in a university release.
Researchers knew that while a human brain has six cortical layers, this framework is not present in bird brains. “That means the structure of the mammalian cortex cannot be decisive for complex cognitive functions such as multitasking,” Letzner says.
Then there is the consideration of nerve density. Pigeon brains have six times more nerve cells than human brains per cubic millimeter of brain. The higher density of neurons in bird brains cuts the average distance between two neurons in half compared to humans.
With nerve-cell signals traveling at a constant speed, researchers wanted to know whether the bird brains, with all those tightly-packed nerve cells, would give them a competitive edge over humans.
The authors designed tests that required abrupt shifts from one task to another. For the tests, 15 human and 12 pigeon participants changed from task to task with two time variables. In the first test, they stopped one task and at that precise moment switched to a second task. The second test provided a tiny delay of 300 milliseconds between quitting the first task and initiating the second task.
Researchers say the first test involved true multitasking. Participants were asked to switch to another task immediately, so the brain had to process two things at once. Stopping the first task was one component. Switching to a different task was another component. Both humans and pigeons were slowed down about equally when presented with this test.
In the second test, the brains got a little break between processes. Researchers compare it to a ping-pong game, where the two processes are repeatedly taking turns. The groups of nerve cells controlling both processes need to keep those signals going back and forth at a constant rate. This is where the pigeons had the edge. With their higher nerve-cell density, they beat the human participants by 250 milliseconds.
“Researchers in the field of cognitive neuroscience have been wondering for a long time how it was possible that some birds, such as crows or parrots, are smart enough to rival chimpanzees in terms of cognitive abilities, despite their small brains and their lack of a cortex,” says Letzner.
The authors believe that their results add another piece to the bird-brain puzzle. When it comes to processing tasks that depend on fast action between different groups of neurons, the birds take first place. The tightly-packed nerve cells of their tiny brains enable these feathered creatures to soar at multitasking.
The study’s results were published in the journal Current Biology.