Abstract
We know that the brain is the seat of the mind. Constructing the reductive model of the conscious mind requires an indication of the laws according to which the mind emerges from biophysical processes occurring in natural brains. Because in Part I, the authors presented the theoretical model referring to the ideal structures of the imagined neural network, we now have easier task, because we need to indicate in the brains of the living beings those processes that functionally correspond to our postulates. Such suitability is not guaranteed by known processes occurring in specialized parts of the brain. The role of the primary sensory areas is a detailed analysis of sensory stimuli with specific modality. They result in analysis of the meaning of all useful stimuli and their interpretation used in various parts of the cortex. The high specialization of individual cortex areas is striking and are the result of evolutionary development of the brain. New brain structures, such as the new cortex, were added on the outskirts of existing structures, improving their performance in the ever more demanding environments, where other intelligent beings ravened. But even as we know the brain organization, we struggle to understand how it works. How neurons that make the brain work together to create the conscious mind. To discover functionally effective processes in the brain, one need to reach for the biophysical properties of the astrocyt-neural network. In this chapter, the authors suggest that some concepts of neuro-electro-dynamics and the phenomena of neuro- and synapto-genesis as well as synaptic couplings may explain the processes of categorization, generalization and association leading to the formation of extensive, semihierarchical brain structures constituting neural representations of perceptions, objects and phenomena. Natural brains meet the embodiment condition. They are products of evolution, so they have intentionality, their own goals and needs. So they can naturally show emotions, drives and instincts that motivate to act. This determines the nature of constructed mental representations. They are the subject of psychological research, which shows the motivation of pain and pleasure in the field of intelligent activities, as well as the motivation of curiosity and the need for understanding in the domain of propositional and phenomenal consciousness. They describe the way pain is felt in organisms as basic quale. The role of other qualia for “how-it-is-like to feel something” and their subjective character was explained, as well as their interspecies specificity was characterized. In this chapter, the authors present an elementary biophysical phenomenon, that is a flash of consciousness. This phenomenon is synaptic coupling formed in the course of learning. They justify that the stream of such phenomena is the foundation of consciousness. They also point out that the astrocytic-neural network meets all the conditions required to generate conscious sensations.
TopMishmash
Guided by modern knowledge, we know that the brain is the seat of the mind. Let us recall information about the specific role of some areas of the brain. This will create a pattern of mutual connections and specializations of known brain structures that explains their interaction.
The brain is not only the central organ controlling our thoughts and behavior, but it also fulfills the more ordinary tasks of controlling processes important for our bodily life. That’s why it connects and works closely with the two external circuits needed to regulate basic vital functions, maintain stability, and deliver sensory information and information for remote muscle control. Both of these circuits fulfill an important role, but they do not determine the feeling of consciousness. That is why the center of our interest will be the central nervous system, which traditionally has two parts: the brain (including the brain stem and cerebellum) and spinal cord. This distinction is related to their evolutionary origin and also to the sequence of development in fetal life. In the brain they are closely related.
Let’s recall their role:
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The spinal cord is a thick bundle of nerves about 1 cm in diameter, and it regulates spontaneous basic reflexes, such as the knee reflex. The stem axon bundle goes from the brain to the spinal cord. It contains also a few motor neurons that control simple reflexes. These neurons allow the body to respond immediately without information processing in the conscious part of the brain. An example is the withdrawal of a hand after a burn or the automatic evasion of an oncoming object, even though it has not even been consciously recognized.
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The cerebellum deals with the control and coordination of movement, the regulation of muscle tone, and maintaining the proper (most often vertical) posture of the body.
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The brain stem, the so-called “reptilian brain,” includes the medulla, pons, and midbrain, and it owes its name to the fact that it appears in cold-blooded animals at an early stage of evolutionary development. It fulfills many regulatory functions. The brain stem affects the remaining areas both by direct stimulation and regulation of various neurotransmitters. According to Wikipedia, there are the respiratory center, heart-regulating center, blood-pressure-regulating center, body-temperature-regulating center, metabolic control center, pituitary gland, eye and ear reflex centers, integration center of motor and sensory stimuli, and reticular formation of the brain stem responsible for the ability to be awake, stay awake, and wake up. The brain stem is also the focus of nerve centers for the following reflex actions: sucking, chewing, swallowing, vomiting, sneezing, coughing, blinking, sweating, and regulating metabolism. (All these reflexes are congenital and are already present in newborns.) Part of the brain stem is, inter alia, the “reticular formation” lying in the medulla of the brain stem. The reticular formation is responsible for the ability to be awake, the state of consciousness, the bones, and the ability to wake the brain. It also stimulates the muscles, providing a general tonus modulated by the cerebellum. The reticular formation is considered to be a “motivational” system, giving rise to various types of actions, switching between extremely different pairs of behaviors regarding general arousal (sleep/wake), movement (rest/movement), eating (hunger/satiety), excretion, and sexual activity. A correlation was found between the excitability of reticular formation and the type of personality.
Let’s move on to the tasks performed by the main parts of the brain proper. The thalamus makes a preliminary assessment of sensory stimuli and sends them to the cortex. It regulates circadian cycles, sleep, and wakefulness. It plays a key role in the integration of sensory and motor information, the processes of attention, and control of access to sensory data. It works with the limbic system, sending signals about the stimulation of emotions, allowing quick, instinctive reactions. The thalamus, cooperating with the brain stem and the cortex, has an influence on what information reaches the cortex and how strongly different areas and ways of its operation are activated.