Until now we have assumed that primary, or sensory, consciousness is only possessed by humans and some of our primate cousins. However, a new study developed by scientists at the University of Tübingen (Germany) and collected by the journal Science , shows, for the first time in history, that crows also possess a certain degree of subjective experience and sensory awareness.
Research indicates that these birds are capable of displaying awareness despite lacking a cerebral cortex, the brain structure previously thought to be responsible for possessing superior intelligence. This is undoubtedly a great step forward in our understanding of animal cognition.
“The results of our study open a new way of looking at the evolution of consciousness and its neurobiological limitations” , comments Andreas Nieder, co-author of the study.
How smart can they get?
Crows and other corvid birds are famous for their intelligence and ability to solve problems. But now, brain scans by this group of German neuroscientists reveal that crows actively think about whatever stimulus they perceive during an experiment , even when it was not present. It’s an incredibly interesting finding, as bird brains have very different and smaller brain cortices than ours.
How to specify the conscience in an animal that does not speak?
It’s complicated. Consciousness is the ability to be aware of yourself and the world around you, know what you know, and think about that knowledge. It improves problem solving and decision making, which we already know crows excel at. But the brains of birds are structured quite differently from those of primates, hence there were considerable doubts about whether they could cross the line into conscious thought.
The experiment
The researchers carried out a series of experiments with two scavenger crows ( Corvus corone ), in which they were each shown some 20,000 colored light signals over the course of dozens of sessions while electrodes implanted in their brain monitored their behavior. brain activity. The birds were trained to recognize visual stimuli by nodding their heads to show when they registered a flashing light.
Some of the lights were dimmer and shorter, making them harder to spot, others more vibrant and clear; However, the more fleeting and diffuse lights caused a divergence in the answers given by the pair of ravens, which led to differences of opinion or subjective experiences.
“Nerve cells that represent visual information without subjective components are expected to respond in the same way to a visual stimulus of constant intensity,” Nieder clarifies. “Our results, however, show conclusively that nerve cells at higher processing levels in the raven brain are influenced by subjective experience, or more precisely produce subjective experiences.”
That is, the researchers were able to show that the nerve cells in the crows’ brain were being influenced by subjective experience because they were consciously perceiving the sensory information of the stimulus. It seems that their brains weren’t simply reacting to the brightness of color instinctively, but were responding to their own internal evaluation.
Assuming the study stands up to further scrutiny, the bigger question is: when did this awareness originate?
“The last common ancestors of humans and crows lived 320 million years ago ,” Nieder said. “It is possible that the awareness of perception arose then and has been transmitted since. In any case, the capacity for conscious experience can be realized in brains structured differently and independently of the cerebral cortex.”
Are there other animals with sensory awareness?
Referencia: Nieder et al., A neural correlate of sensory consciousness in a corvid bird. Science (2020). science.sciencemag.org/cgi/doi … 1126/science.abb1447
