Ravens are not only smart birds – they also have their own form of consciousness that allows them to understand the world around them. In other words, they are capable of experiencing subjective experiences just like humans. The corresponding study was published in the journal Science.
This is called primary, or sensory, consciousness, and has previously only been identified in primates. This means that our understanding of how consciousness arises needs to be revised.
“The results of our study provide a new perspective on the evolution of perception and its neurobiological limitations,” said animal physiologist Andres Nieder of the University of Tübingen.
It is difficult to identify consciousness in animals without speech skills. This is the ability to be aware of yourself and the world around you, to accumulate knowledge, and think about them. This makes it possible, in particular, to solve problems, in which the crows have succeeded.
Primary consciousness is associated with the primate cerebral cortex, a complex, multi-layered region of the mammalian brain. This is the most basic form of consciousness responsible for the perception of the world in the present, as well as in the immediate past and future. In this case, the brain of birds is structured completely differently than the brain of primates. So while corvids – a family of birds that include ravens and ravens – are incredibly intelligent and possess the cognitive abilities of primates, researchers were left with questions about whether they could shift to conscious thinking. This required a series of experiments.
At first, birds were taught to respond to visual stimuli. They were shown screens that displayed lights. If the crows saw the lights, they had to turn their heads to give an affirmative signal. Most of the lights were clearly visible, and crows reliably reported seeing them.
But some of the lights were harder to see. In the dimmer and shorter stage, the crows sometimes reported seeing signals and sometimes not. This is where subjective experience comes into play. For the experiment, each of the crows was shown approximately 20,000 signals distributed over dozens of sessions. Electrodes implanted in their brains recorded their neural activity.
When crows recorded a “yes” response to visual stimuli, neuronal activity was recorded in the interval between seeing light and issuing a response. When the answer was no, no such increased neuronal activity was observed. This connection was so reliable that it was possible to predict the crow’s response based on brain activity.
According to Nieder, the nerve cells at the higher levels of processing in the crow’s brain are influenced by subjective experience, or more precisely, they produce subjective experience. This allows the birds to respond correctly to external stimuli.
The results of experiments with crows give scientists the right to believe that not only primates experience subjective experience, and the multilayered structure of the brain is not a requirement for this. In fact, research has shown that the smoothness of a bird’s brain is not at all indicative of lack of complexity.
Biopsychologist Martin Stakho of the Ruhr University in Bochum and colleagues have used 3D imaging and neural circuit tracing techniques to describe the anatomy of the pigeon and owl brains. They found that the brains of both birds were strikingly similar to those of mammals.
It is possible that similar cognitive abilities developed independently in both birds and mammals – a phenomenon known as convergent evolution. But it’s also possible that our brains are more closely connected than their differences would suggest.
“The last common ancestors of humans and crows lived 320 million years ago,” Nieder said. – Perhaps consciousness arose then and since then has been inherited. In any case, the ability to gain experience can be realized in the brain with a different structure and independently of the cerebral cortex. ” This means that consciousness may be much more common in birds and mammals than we thought. If this is confirmed, the next and perhaps even more interesting question arises: do these animals also have secondary consciousness?