This may be the neural anatomy needed to think of birds like homing pigeons.
Ruth Swann / World Stock Photo
By Virginia Morel
Never before has “Bird Brain” been so appreciated: in recent years, birds have been found to make tools, to understand abstract concepts, and to recognize paintings by Monet and Picasso. But their lack of neocortex, the protective covering of the fetus in mammals, where field memory, planning and problem solving are concerned, has long puzzled scientists. Now, researchers have discovered a previously unknown system of microcircuits in the avian brain that may be similar to mammalian neocortex. And in a separate study, other researchers have linked the same field to conscious thought.
The two papers are already considered groundbreaking. “It has always been believed that the alien brain architecture of birds limits thinking, consciousness and very advanced cognition,” says John Marzloff, a wildlife biologist at Seattle University and a Seattle consultant. “Researchers demonstrating the cognitive abilities of birds will not be surprised by these results,” he adds, but they will be relieved. “
Indeed, it was because of the same cognitive abilities as birds and mammals that Martin Stacho, a neuroanatomist at Ruhr-University Bochum, decided to investigate Avian Forebrain, who controls perception. A total comparison of mammals and avian brains suggests that “they have nothing in common,” he says. “Yet birds and mammals have many similar cognitive skills.”
To find out how ornithologists support this mental genius, Stacho and his colleagues examined microscopic fragments of three pigeon brains using 3D polarized light imaging. This high-resolution technique allows them to analyze the circuitry of the forebrain field known as the pallium, which is thought to be similar to the mammalian neocortex. Although the pelvis lacks six layers of cortex, it has distinctive structures connected by long fibers.
Scientists compared images of bird droppings to rats, monkeys and human cortex. Their analysis showed that the fibers in the bird’s nest are arranged in the same way as the fibers in the mammalian mantle.
Researchers also imagined connections between neurons in the brains of two remotely related avian species: pigeons and owls. After deeply removing the brains of birds with anesthesia, the scientists injected crystals into the dissected brain and found circuits in the sensory regions that were similar to those found in mammalian neocortex. It is this neuroarchitecture – the connections between structures rather than their own – that explains why birds are as cognitively gifted as mammals, they report today. Science.
“This research confirms an old saying that what appears to be fraudulent,” says Marzloff. Although bird and mammal brains “look very different, this study shows that they are actually very complementary wired.”
But do birds have a conscious experience? Are they aware of what they see and do? To find out, Andreas Nieder, a neurophysiologist at the University of Tebangen, observed the brains of Carian crows (Corvus Coron) As they responded to the signals. Known as “feathered clowns” for their intelligence, these crows and their cousins have also been shown to be causal. But predicting consciousness from such experiments is challenging, Neider says.
Therefore, he and his colleagues used a similar test that performs a primary check for signs of consciousness – a mental state that occurs even with the sudden activation of certain neurons. They trained two lab-standing, 1-year-old caribou crows to move or remain still in response to a dizzy cue displayed on a monitor. When cured, the birds were rewarded. Scientists then implanted electrodes in the crows’ brains to record their responsive neuronal signals. When the crows reacted, their neurons fired, indicating that they had consciously seen the cue; But when they weren’t, their neurons were quiet. The neurons fired in agreement with the crows’ action were in Palia, the researchers said, even today. Science. Nyder calls this an “empirical marker of sensory consciousness in the bird’s brain,” found in primates.
It is certain to stimulate debate, as “some researchers argue that consciousness is uniquely human,” says Irene Pepperberg, a comparative psychologist at Harvard University, known for working with Alex, the African gray parrot who talks about abstract concepts in English. Curry. Pepperberg was not involved in the new study but found it “really exciting.”
Stacho and Fearless added that building blocks for mammals and avian knowledge may have been present about their last common ancestor about 320 million years ago. “Of course, the brains of mammals and birds evolved differently,” says Stacho. “The amazing thing is that they are still very similar in their cognitive and cognitive abilities.”
