Science, Art, Litt, Science based Art & Science Communication
Krishna: Yes, neurons are required for something, living things, to have consciousness, at least in our universe.
Consciousness is scientific, not spiritual.
Consciousness. Image source: Nautilus
The concept of Universal consciousness originated in spirituality, not in science and therefore has no evidence and although a part of the scientific community deals with it, there are no specific guidelines to define it and somehow this leads to a controversial part of science.
Consciousness is the result of neuron activity. In our standard view of things, consciousness exists only in the brains of highly evolved organisms, and hence consciousness exists only in a tiny part of individuals of the universe and only in very recent history.
People use it to mean something quite sophisticated, such as self-awareness or the capacity to reflect on one’s own existence.
Do Individual atoms have consciousness? No!
According to the scientific community, consciousness arises from the collective interactions going on in the particles that make up our “brain.” Therefore, there might be something about the properties of matter, as currently measured, that contains some “essence” of consciousness (1).
It is particular phenomenological groupings of sub-atomic particles that allow consciousness to arise. Science would argue consciousness arises from the structural nature of the “neuron.” Since not all molecules are replicant like DNA, nor are all cells “neurons”, the basis of consciousness is not implicit to the standard model, but explicit to a small set of the phenomenological groupings that arise from it. It is the way matter is arranged, that decides about its consciousness.
So quantum action might be a precondition of consciousness, but not necessarily the only condition. Phenomenological groupings (like DNA and the neuron) exhibit behavioural perceptions unique to those groupings. The property arises from the shape of the grouping, not the components. A unified theory of physics will arrive at a point where matter has no properties except relative location on which an action principle works. So, consciousness would arise from phenomenological groupings, not from properties of matter.
Consciousness requires several steps up in order and complexity. That can be obtained only by way of interactions of specific groupings of molecules working in a specific way.
Although individual oxygen, carbon and iron atoms can become part of brain structure, contribute some way with their properties, they themselves cannot cause consciousness. They alone don't cause consciousness in other parts of the body. Without interaction between specific-chemical-interaction-structured-neurons and their interactions with one another in a special way, there won't be any consciousness. Although nerve cells exist through out the body, only the specific collective interactions of neurons with the help of other neurons in the body in a brain causes consciousness. But other neurons help in the process. Only when other neurons send signals that your hand 's injured, you become aware that your hand 's injured when the specific neural process in your brain determines and fixes it.
Consciousness is the result of our neurons in the brain interacting with one another at a higher scale to make us conscious!
A fully developed fetus in the womb can be somewhat conscious. But before different cells are differentiated, you have interactions between cells through chemical signaling. The fetal brain does not begin to develop until 3-4 weeks into the pregnancy, at which point it is little more than a hollow tube filled with dividing neurons. Between weeks 4 and 8 this neural tissue grows forming the major divisions of the adult brain. By 8 weeks recognisable facial features have developed and the cerebral cortex separates into two distinct hemispheres. By the end of the first trimester (12 weeks) nerve cells are beginning to form rudimentary connections between different areas of the brain. However, these connections are sparse and incapable of performing the same functions as an adult brain. So by 12 weeks, although the fetus is certainly starting to look like a little human, the neural circuits responsible for conscious awareness are yet to develop.
As the complexity of the fetal brain grows, forming structures similar to those we recognise in the adult, so does the fetus’ ability to experience and respond to its environment. Studies have shown that from 16 weeks the fetus can respond to low frequency sound and by 19 weeks will withdraw a limb or flinch in response to pain. An observer would certainly think these responses look very much like the start of conscious awareness. However, during these early days the neural pathways responsible for converting senses to conscious experiences have yet to develop. This means what we are seeing are just reflexes, probably controlled entirely by the developing brainstem and spinal cord.
In fact, we know that the brain structures necessary for conscious experience of pain do not develop until 29-30 weeks, while the conscious processing of sounds is only made possible after the 26th week. Even when the fetal brain possesses all its adult structures, scientists are cautious to assume it possesses what we refer to as ‘consciousness’. This is mainly because the low oxygen levels and a constant barrage of sleep-inducing chemicals from the placenta ensure that, until birth, the fetus remains heavily sedated. It is not full consciousness. In the last few weeks before the birth the fetus develops some memories. Fetuses can listen to speech within the womb, but the sound-processing parts of their brain become active in the last trimester of pregnancy.
Consciousness requires a sophisticated network of highly interconnected components, nerve cells. Its physical substrate, the thalamo-cortical complex that provides consciousness with its highly elaborate content, begins to be in place between the 24th and 28th week of gestation. Roughly two months later synchrony of the electroencephalographic (EEG) rhythm across both cortical hemispheres signals the onset of global neuronal integration. So, many of the circuit elements necessary for consciousness are in place by the third trimester.
Before birth, full consciousness is not well developed in a fetus (1).
Some people argued as part of answer to this question that out of body experiences show consciousness can occur without a brain: This is my reply to them:
The mechanism behind some of these strange experiences is in the way our brains process sensory information. What we see as "reality" around us is only the sum of all the sensory information our brain is receiving at any given moment. When you look at a computer screen, the light from the screen hits your retinas, and information is sent to the appropriate areas of the brain to interpret the light patterns into something meaningful -- in this case, the words you are currently reading. An even more complex system of nerves and muscle fibers allows your brain to know where your body is in relation to the space around it. Close your eyes and raise your right hand until it is level with the top of your head. How do you know where your hand is without looking at it? This sensory system allows you to know where your hand is even when your eyes are closed. Trauma affecting functional areas of the brain, such as the somatosensory and visual cortexes, could cause hallucinations that get interpreted as NDEs. Now imagine that all your senses are malfunctioning. Instead of real sensory input from the world around you, your brain is receiving faulty information, possibly because of drugs, or some form of trauma that is causing your brain to shut down. What you perceive as a real experience is actually your brain trying to interpret this information. Some have theorized that "neural noise," or an overload of information sent to the brain's visual cortex, creates an image of a bright light that gradually grows larger. The brain may interpret this as moving down a dark tunnel.
The body's spatial sense is prone to malfunction during a near-death experience as well (2). Out of body experiences are malfunctioning brain’s interpretations and are a part of consciousness too.
So the answer to the first part of your Q is ‘‘YES, but … not only neurons- arranged in a certain way- are required to develop consciousness, they should also work only in a certain way.”
Second part: this is not the realm of genuine science. It borders between genuine science and spiritualism leaning towards the latter. No evidence means it cannot be accepted as genuine science.
The answer to the third part is “NO”.