Although quantum mechanics tells you that the material that makes up your body has a very low probability of appearing on the moon in an instant. But classical mechanics tells you that this is impossible, because the particles in your body are entangled with collective freedom and the wave function collapses. It is actually a popular scheme to explain consciousness from the perspective of quantum mechanics.
Penrose, a famous physicist who won the Nobel Prize in Physics last year (2020) for discovering that the formation of black holes is a powerful prediction of general relativity, is keen on explaining consciousness with quantum mechanics. In his eyes, consciousness is produced by quantum entanglement and quantum superposition.
His logical reasoning is as follows:
Godel's Incomplete Theorem: In a set of axioms, there must be truths that cannot be proved.
Human mathematicians can understand truths that cannot be proved.
Human consciousness is beyond justice.
So this is due to the collapse of wave function in the brain, and human consciousness is determined by quantum mechanics.
There are also some physicists trying to explain consciousness through string theory. However, the concept of Penrose has also caused great controversy in the scientific community, and even there have been many opposing voices.
I won't discuss it here. After all, this is just an immature conjecture of Penrose, and it is outside his research field. However, China was keen on this metaphysical research, and even became a master's thesis in a certain field of philosophy department. However, whether using quantum mechanics to explain consciousness or using string theory to explain consciousness is tantamount to improving the explanation of human consciousness. This belongs to human conceit.
I dare not say that Penrose is wrong, but human beings are still too small for the origin of the universe. From the perspective of neuroscience, there is a definite demand for our neural signal transmission.
For example, if you see a beautiful painting, the information you see is converted into electrical signals through cone cells and visual receptors, and then transmitted to your visual center. The expression of this information is accurate, so you can make clear its composition, lines and colors.
On the contrary, when the signal transmission in your brain becomes inaccurate, you may feel dizzy, dizzy, or even hallucinate and see pictures that have never appeared before. Or, when the neural pathway of dopamine is abnormal, you may have cognitive defects such as schizophrenia, hallucinations and delusions.
Besides, 2/3 of inexplicable migraine is due to arterial pulsation, and 1/3 is a very complicated neural mechanism, such as ionic changes in meningeal blood vessels and abnormal function of brain stem nuclei. In essence, it is an abnormal ion channel and nerve signal pathway. In addition, about 30% people sneeze in strong light.
From the perspective of neuroscience, the most likely reason is that the trigeminal nerve and the visual nerve, which control the sensation and movement of the head and face, are closely connected, and there may be a cross reaction between them. When the bright light from the outside suddenly enters the retina, the pupil will contract rapidly, triggering the optic nerve reflex. These nerve signals may be transmitted to the trigeminal nerve by mistake, and the brain will send out the wrong sneezing instructions, thus causing the occurrence of "sneeze reflex".
This reflex can be inherited. If one parent has a slight sneezing reflex, there is a 50% chance that it will happen to the child.
To sum up, both information perception, signal processing and external behavior of our brain need the accuracy of neural pathways and signals. So, how do precise neural pathways become complex consciousness? Before answering this question, let's take a look at what consciousness is.
The most classic way for human beings to judge consciousness is the mirror image test: in previous studies, it was found that bottlenose dolphins, magpies, apes and elephants can all pass the mirror image test. These are very clever animals. They seem to be self-conscious, so people take it for granted that they are conscious. Later, it was found that cats, dogs and octopuses who looked smart could not pass the mirror test.
It seems that this shows that they are unconscious.
But in later research, it was obvious that someone was hit in the face. In the Indo-Pacific region, there is a kind of fish called schizophrenic fish, which is also called "medical fish" because it can help other large fish clean up parasites. A study at the beginning of 20 19 showed that cleft lip fish could pass the mirror image test.
Even on 20 15, a study claimed that ants can pass the mirror test: although the mirror test of ants is controversial. But from people to cleft lip fish, it is not difficult to find that all those who can pass the mirror image test are social animals without exception. Social animals, on the other hand, have strong sociality, so it is necessary for them to distinguish the identity of each individual in the process of ethnic interaction.
In the process of distinguishing other members, self-knowledge has a foundation. However, judging by the mirror test alone is actually problematic. Let's suppose that there are two animals with the same intelligence. The self-cognition of animal A is beneficial to pass the mirror image test, while the self-cognition of animal B is not conducive to pass the mirror image test.
So when humans use mirror test to judge whether animals have self-awareness and which animals are smarter. Directly, it will be preconceived: A has strong self-awareness and is smarter. B has no self-knowledge and is not as smart as A, but obviously, B's judgment is probably wrong.
There are also examples in reality. Although dogs can't pass the mirror test, some studies show that dogs can recognize themselves by smell. Through the mirror test, I came to an arbitrary conclusion about consciousness, which reflected the conceit of human beings. Even if we don't discuss it, crows, animals without neocortex, are still very smart. From the perspective of mammalian neocortex development, we simply say that consciousness will not suddenly appear, and the neocortex will continue to develop and become complicated from mice to humans.
It is possible that consciousness has existed for a long time.
Let's assume that the score of mice is 1 and that of humans is 100, so the consciousness of macaques who can't pass the mirror test may be 59, not zero. If we say that many times, when we judge whether lower animals are conscious, it often lies in our definition of consciousness itself. But what we really care about is not the definition of consciousness, but the process from 1 to 100.
So, how did consciousness go from 1 to 100? In the field of EEG, there is a concept of brain entropy (BEN), which represents the irregularity of brain system and information processing ability. The human brain is often in an active state of fluctuation. Entropy brain represents the ability of the brain to transmit information, and also refers to the number of neural states that the brain can access.
The entropy of human brain has these characteristics: 1, and brain entropy is highly correlated with consciousness. 2. The entropy of human brain is greater than that of other animals (here, it refers not to the degree of chaos, but to the total amount of information). 3. The higher the general intelligence, the higher the entropy (ditto). 4. When people are in psychedelic state, rapid eye movement, psychotic episode and sleep epilepsy, their entropy increases. The higher the intelligence, the higher the entropy, because the more information the brain processes.
Mental patients have higher entropy because the information they process is more chaotic. It can be said that an equally high entropy person may be Einstein, but a person may be mentally ill. In the psychedelic state, people will show a certain "primary consciousness". For example, when you subconsciously go to the toilet at night, someone calls you and you react, but when you get up the next day, you don't remember anything. This is a kind of "primary consciousness".
After people gradually wake up from the entropy of primary consciousness, the entropy of human brain will present a subcritical state. In this subcritical state, we will show enough sober consciousness. 1 year-old babies will show primary consciousness, while 1 year-old babies are likely to be worse than orangutans of the same age. (The main reason is that human babies are premature and have a long sexual maturity cycle. The human mind has the ability to maintain secondary consciousness, which can improve the response to objectivity and show more order, thus the brain shows entropy reduction. It can also be considered that the degree of order is higher, so less additional information is needed when expressing the same amount of information.
Generally speaking, people's secondary consciousness depends on the coherence and hierarchical structure of brain tissue and the processing ability of the system. The human brain always keeps a strict balance between order and chaos. When people are in the secondary consciousness state, they don't deal with external information so carefully, and they are easily influenced by emotions, prejudice, anxiety and desire.
In the process of evolution, the human brain has the ability to control entropy at the sub-critical point, which is helpful to promote realism, foresight, careful thinking, and the ability to identify and overcome wishful thinking and fantasy. Of course, the process of suppressing secondary consciousness also limits the space for consciousness expansion. For example, compared with children's brains, adults' brains always lack imagination. Of course, the total ability of adult brain to process information is higher, and the brain entropy is naturally higher.
When the secondary consciousness is suppressed, the primary consciousness will be more active. Generally speaking, 25 years old is the peak of human entropy and information processing ability. The brain entropy of different age groups is simulated by tossing coins, choosing cards, rolling dice, choosing one of nine circles, and filling in grids. Experiments show that human beings' ability to process information is the highest around the age of 25, mainly concentrated in the young and middle-aged stage. Although the birth process of consciousness is still in the hypothetical stage, researchers may have found the switch of consciousness-the central lateral thalamus.
Researchers at the University of Wisconsin-Madison found that when the central lateral thalamus was stimulated by 50 Hz, anesthetized macaques could wake up and have normal waking behavior. The monkey opened his eyes, his vital signs changed, his face and body began to move, and he reached for nearby objects.
However, after turning off the electrical stimulation, in just a few seconds, the monkey will close his eyes again and return to the unconscious state. The above experiments must be very accurate to be realized. A 50 Hz electric pulse can only click on a specific location of only 20 nanometers. This shows that the central lateral thalamus has a certain priming effect on consciousness. But can this experiment prove that consciousness has obvious regional functions such as movement, feeling and vision like the central cortex? That's not necessarily true.
Hydrocephalus anencephaly is a congenital disease, which is usually manifested by the loss of both cerebral hemispheres (cerebral cortex) and replaced by a thin sac filled with cerebrospinal fluid. In addition to the cerebral cortex, the child's brain stem, cerebellum and meninges are all sound, and some may have some temporal lobes, occipital lobes or frontal lobes. Although these children often die young, most of them can show conscious activities. This is enough to show that although the cerebral cortex plays an important decisive role in consciousness, it is definitely not a necessary condition for consciousness.
From this point of view, judging the "lower" animals without cerebral cortex will not lead to the inference of consciousness, and it is also untenable. Although birds also have cerebral cortex, the actual "consciousness" of birds can appear without going through the cerebral cortex. There are indications that the birth of consciousness may be related to the overall activity of the brain.
Although early brain research tended to be divided into regions. However, many kinds of neuron coupling systems have been discovered in academic circles for a long time, and a special subject-synchronous dynamics of neuron coupling systems was born. With the rapid development of electroencephalogram (EEG), magnetic resonance imaging (MRI) and positron emission tomography (PET). In recent years, the cross-frequency coupling network between different regions of the brain and the dynamic coupling between whole brain neurons and neurotransmitter system have been discovered.
These studies show that the brain has a strong integrity when working together. Most of people's frontal lobe, parietal lobe, occipital lobe and temporal lobe cortex are called commissural areas, which can receive multi-channel sensory signals and integrate neural activities in various functional areas. 90% of people's left and right brains belong to a combined system. When the corpus callosum between the left and right brains breaks, the consciousness of the left and right brains will be confused at first.
The left and right brains will move independently, cooperation will disappear, and two things will be done at the same time. Draw a circle with your left hand and a square with your right hand, which is easy for people with split brains. However, due to the disunity between the left and right brain thinking, many behaviors of schizencephalic people tend to be uncontrollable, and even the right brain may control the left hand to attack people:
This animation should come from the movie scene, the real situation will not be so exaggerated, and the hand is not uncontrollable.
People often have crazy flashes. The flash of this thought is often controlled by the right brain (human emotional impulse).
Under normal circumstances, the left brain, which is connected with the left brain and is responsible for thinking logic, will stop the strategy of the right brain in time before the neural signal appears. When the left and right brains are still connected, there is often only one contradictory strategy. But for schizencephaly, the two strategies can be kept at the same time. For example, in normal people, when the brain has a flash of self-harm, the other half of the brain directly stops it, and nothing will happen again. But for people with split brains, stopping will happen after action.
The consciousness of "I" itself is the unity of the left and right hemispheres. Of course, because the brain can be connected by other parts, for people with brain division, consciousness is still complete, not really divided. When people hesitate between reason and emotion, it is not a contest between left and right brains. So, do you often win with your left brain or your right brain?
Of course, the brain also has extraordinary adaptability, and not all people with brain division will have a serious impact on life. In children without corpus callosum, the brain redistributes signals through other brain regions, such as communication between midbrain and forebrain, to ensure communication between left and right brains. Although there is no corpus callosum and brain function is only slightly affected, it fully shows the plasticity of the brain.
Judging from some cases in which brain tissue was removed and survived by being shot in the head, many brain tissues were missing, even half of the head was gone, but consciousness was not greatly affected.
It can be seen that the plasticity of the brain is far from being imagined. This plasticity can never be explained by the functional division of the brain. Although the neocortex is only 3 mm thick, it has 6 layers:
In order to deal with all kinds of complicated information, human neocortex has formed different regions, which are mainly divided into three regions: primary sensory region, primary motor region and contact region:
Sensory areas include: hearing, vision, somatosensory, etc. At the same time, human beings also have a special language area, which is sometimes classified as a part of the contact area. Nerve cells in primary sensory area and primary motor area are highly specific, and directly receive nerve signals from receptors, and connect with occipital lobe, temporal lobe and central anterior and posterior gyrus to form corresponding contact areas.
The primary reflex activity of cerebral cortex is possessed by most mammals, but the contact area of lower mammals is not developed, and their consciousness is mainly primary consciousness. After the primate branch evolved into apes, the cortical contact area began to develop rapidly, forming the basis of higher consciousness.
In addition to the language area, the contact area also includes: pillow contact area related to self-body view, belief and emotional attitude; Temporal lobe contact area of multi-sensory integration and conceptual conception: frontal lobe contact area responsible for judgment, foresight and personality attributes.
Except the prefrontal area, all parts of this area include visual, auditory and somatosensory contact areas.
Why has the human cerebral cortex evolved more complicated? The neocortex not only occupies 94% of the cerebral cortex, but even occupies more than 70% of the whole brain.
Neocortex is highly related to memory, learning and even consciousness formation. From early mammals to primates, the biggest change lies in the evolution of life skills, sports ability and sensory ability. These comprehensive reasons promote the development of brain contact area and make neocortex fold out more and deeper sulcus gyrus.
Only when the newly added neocortex has a larger surface area can it support complex brain activities. Consciousness can never be attributed to a single factor. Although neocortex can well explain human higher consciousness, for crows with few neocortex (compared with humans), it is obvious that other factors need to be considered more when studying their consciousness.
Generally speaking, from mice to humans, the process of consciousness from 1 to 100 is actually relatively clear. Just from 0 to 1, when and how it happened, it may take us a long time to understand. However, with the development of brain science, we are getting closer to the truth about consciousness.
PS: Although many people criticize that artificial intelligence is not real artificial intelligence, in fact, with the increasing complexity of artificial intelligence systems, although each information unit is as accurate as neural pathways, with the increasingly irregular activities of neural networks, the generation of consciousness is almost inevitable. At present, artificial intelligence is too simple, and the first one to produce real advanced consciousness in the future must be supercomputer (even supercomputer matrix).