If only scientists knew where the consciousness lived.
In the biotech industry, a controversial idea is discussed: to grow human bodies without crust of large hemispheres and use them as a source of organs for transplantation. Proponents of the approach come from a simple assumption: without cortex there is no consciousness, pain and fear, and the body can be considered as biological material. But neuroscientists are increasingly arguing with such logic. Some researchers believe that consciousness may depend not only on the cortex, but also on the more ancient parts of the nervous system.
The bark of the large hemispheresis is an external folded layer of the brain. In a person, it is associated with speech, abstract thinking, planning, self-esteem and a detailed picture of the world. Therefore, the crust was long considered the main point where a conscious experience arises. Deeper are the subcortical structures: the brain stem, thalamus, basal ganglia, tonsils, hippocampus and other parts. They support wakefulness, emotions, the work of internal systems, simple reactions and the transmission of signals from the senses.
In a healthy brain, the bark and subcortical parts constantly exchange signals. Information from the sense organs passes through the lower structures, rises higher, and then returns as a body command. Most neuroscientists agree that human consciousness depends on this connection. The dispute begins with another question: can subcortical departments maintain at least the simplest sensations if there are no crusts?
Researchers who associate consciousness primarily with the cortex, respond negatively. In their version, subcortical structures include the brain, maintain wakefulness, and control basic reactions, but do not create subjective experiences. Opponents consider this conclusion too harsh. In their opinion, science could overestimate the role of the cortex, because vision, speech and complex thinking are easier to study through the upper parts of the brain.
One of the main arguments is to have hydranencephaly. In this case, a rare violation is a significant part of the cortex, and the cavities inside the skull are filled with liquid. Such patients were often described as people in an unconscious or vegetative state. However, observations of families gave a more complex picture: the children reacted to the environment, laughed, played, showed emotions and turned to what was happening around. They could not tell about their feelings, but their behavior is difficult to reduce to a set of automatic reactions.
Here the dispute becomes especially difficult. Behavior in itself does not prove the presence of consciousness. A newborn, animal or patient without speech can not explain what exactly he feels. Therefore, scientists have to work with indirect signs. Similarly, people talk about dogs and cats: animals do not describe in words pain, joy or fear, but their reactions make you consider the possibility of experiences.
Proponents of the leading role of the cortex object: the reaction to the outside world does not mean a conscious feeling. The brain is able to perform many actions without the participation of consciousness. A good example is blindness. If a visual cortex is damaged, a person can claim that he does not see anything, but still guess the location of objects or react to movement. According to this logic, children with hydranenecephaly and some animals may respond to stimuli without subjective experience.
The other side offers to look not only at vision, but above all at the senses. Visual information is really often processed without awareness, but pain, fear, hunger, anxiety and pleasure work differently. They help the body choose between needs: eat, sleep, look for a partner, avoid danger, save energy. In this interpretation, consciousness could begin not with reflection, but with a simple sensation that prompts a living thing that is important right now.
Evolution makes the dispute wider. The mole catering appeared relatively late, hundreds of millions of years ago. Subcortical systems are much older and go back to early vertebrates. If simple sensations arise in these departments, the question of consciousness affects not only people, mammals and birds. The discussion includes fish, amphibians, reptiles, and possibly octopuses and part of insects with similar nerve centers.
Even supporters of the subcortical role of consciousness do not deny the importance of the cortex for humans. Speech, memory, imagination, planning, and detailed perception require complex cortical networks. The difference applies to the minimum level of conscious experience. The scrupulous departments, according to this version, can create basic sensations, and the cortex makes the experience detailed, coherent and accessible for thought.
Interest in subcortical structures is also connected with how the brain collects a single perception. The nervous system constantly receives light, sound, smells, signals from the body and emotional reactions. A person does not perceive everything as a stream of individual impulses. The brain connects the data into the overall picture. Supporters of the subcortical role suggest that the lower departments can participate in the unification of different signals. So far, this is a hypothesis, not a generally accepted theory.
It is difficult to verify this idea: the subcortical structures are located deep, and the intervention in these zones for a long time remained rude and risky. Now researchers are counting on transcranial focused ultrasound. The method allows you to influence the internal parts of the brain without surgery: ultrasound waves are directed into the desired area through the skull. If stimulation can change pain, fear, pleasure, or other sensations without directly affecting the cortex, an approach that connects consciousness primarily to the cortex will face a serious challenge.
There is no single theory of consciousness yet. Some experts consider the key buttons of feedback, others associate the basic sensations with ancient emotional and bodily systems, others are trying to combine both approaches. In 2024, nearly 600 scientists signed the New York Declaration on Animal Consciousness. The document recognizes the almost undeniable presence of conscious experience in mammals and birds, as well as the real possibility of experiences in all vertebrates and many invertebrates. For a dispute about bodies without bark, this is an important reference point: if the state of a living being cannot be determined reliably, its well-being is better to take into account in advance.
In the biotech industry, a controversial idea is discussed: to grow human bodies without crust of large hemispheres and use them as a source of organs for transplantation. Proponents of the approach come from a simple assumption: without cortex there is no consciousness, pain and fear, and the body can be considered as biological material. But neuroscientists are increasingly arguing with such logic. Some researchers believe that consciousness may depend not only on the cortex, but also on the more ancient parts of the nervous system.
The bark of the large hemispheresis is an external folded layer of the brain. In a person, it is associated with speech, abstract thinking, planning, self-esteem and a detailed picture of the world. Therefore, the crust was long considered the main point where a conscious experience arises. Deeper are the subcortical structures: the brain stem, thalamus, basal ganglia, tonsils, hippocampus and other parts. They support wakefulness, emotions, the work of internal systems, simple reactions and the transmission of signals from the senses.
In a healthy brain, the bark and subcortical parts constantly exchange signals. Information from the sense organs passes through the lower structures, rises higher, and then returns as a body command. Most neuroscientists agree that human consciousness depends on this connection. The dispute begins with another question: can subcortical departments maintain at least the simplest sensations if there are no crusts?
Researchers who associate consciousness primarily with the cortex, respond negatively. In their version, subcortical structures include the brain, maintain wakefulness, and control basic reactions, but do not create subjective experiences. Opponents consider this conclusion too harsh. In their opinion, science could overestimate the role of the cortex, because vision, speech and complex thinking are easier to study through the upper parts of the brain.
One of the main arguments is to have hydranencephaly. In this case, a rare violation is a significant part of the cortex, and the cavities inside the skull are filled with liquid. Such patients were often described as people in an unconscious or vegetative state. However, observations of families gave a more complex picture: the children reacted to the environment, laughed, played, showed emotions and turned to what was happening around. They could not tell about their feelings, but their behavior is difficult to reduce to a set of automatic reactions.
Here the dispute becomes especially difficult. Behavior in itself does not prove the presence of consciousness. A newborn, animal or patient without speech can not explain what exactly he feels. Therefore, scientists have to work with indirect signs. Similarly, people talk about dogs and cats: animals do not describe in words pain, joy or fear, but their reactions make you consider the possibility of experiences.
Proponents of the leading role of the cortex object: the reaction to the outside world does not mean a conscious feeling. The brain is able to perform many actions without the participation of consciousness. A good example is blindness. If a visual cortex is damaged, a person can claim that he does not see anything, but still guess the location of objects or react to movement. According to this logic, children with hydranenecephaly and some animals may respond to stimuli without subjective experience.
The other side offers to look not only at vision, but above all at the senses. Visual information is really often processed without awareness, but pain, fear, hunger, anxiety and pleasure work differently. They help the body choose between needs: eat, sleep, look for a partner, avoid danger, save energy. In this interpretation, consciousness could begin not with reflection, but with a simple sensation that prompts a living thing that is important right now.
Evolution makes the dispute wider. The mole catering appeared relatively late, hundreds of millions of years ago. Subcortical systems are much older and go back to early vertebrates. If simple sensations arise in these departments, the question of consciousness affects not only people, mammals and birds. The discussion includes fish, amphibians, reptiles, and possibly octopuses and part of insects with similar nerve centers.
Even supporters of the subcortical role of consciousness do not deny the importance of the cortex for humans. Speech, memory, imagination, planning, and detailed perception require complex cortical networks. The difference applies to the minimum level of conscious experience. The scrupulous departments, according to this version, can create basic sensations, and the cortex makes the experience detailed, coherent and accessible for thought.
Interest in subcortical structures is also connected with how the brain collects a single perception. The nervous system constantly receives light, sound, smells, signals from the body and emotional reactions. A person does not perceive everything as a stream of individual impulses. The brain connects the data into the overall picture. Supporters of the subcortical role suggest that the lower departments can participate in the unification of different signals. So far, this is a hypothesis, not a generally accepted theory.
It is difficult to verify this idea: the subcortical structures are located deep, and the intervention in these zones for a long time remained rude and risky. Now researchers are counting on transcranial focused ultrasound. The method allows you to influence the internal parts of the brain without surgery: ultrasound waves are directed into the desired area through the skull. If stimulation can change pain, fear, pleasure, or other sensations without directly affecting the cortex, an approach that connects consciousness primarily to the cortex will face a serious challenge.
There is no single theory of consciousness yet. Some experts consider the key buttons of feedback, others associate the basic sensations with ancient emotional and bodily systems, others are trying to combine both approaches. In 2024, nearly 600 scientists signed the New York Declaration on Animal Consciousness. The document recognizes the almost undeniable presence of conscious experience in mammals and birds, as well as the real possibility of experiences in all vertebrates and many invertebrates. For a dispute about bodies without bark, this is an important reference point: if the state of a living being cannot be determined reliably, its well-being is better to take into account in advance.
