«To dream is to get some air in infinity. » Anne Barratin How to explain the variety, intensity and richness of our mental manifestations orchestrated by an organ limited to our skull.
We will first describe the consciousness and revisit the dream, the near death experience and the terminal lucidity.
We will then move on to the formation of our memories and the physical limits of memory.
4.1 Consciousness perception
The consciousness can be defined as the perception, the
knowledge of oneself and of the outside world.
It is expressed through our thoughts, emotions and feelings, to which corresponds a specific degree of attention and neural activity.
The attention manages the consciousness, it can be outward or inward turned and more or less focused on a particular point.
We distinguish the consciousness from the present moment: the brain reacts, the awakened consciousness: the events are memorized and the self-consciousness: the person is conscious of his actions.
The brain plays a key role in the production of consciousness, involving the cortex (perception, emotion, awareness), the thalamus* (attention) and the hippocampus (memory).
Summary
The consciousness is expressed through our thoughts, feelings and emotions.
The brain plays a key role in the production of consciousness, involving the cortex, thalamus and hippocampus.
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4.2 Consciousness manifestation
Where do our emotions, feelings, ideas, intuitions come from?
How can we explain the richness and intensity of our dreams or of the near death experiences?
What are the commonalities between these mind
manifestations. Are they only the result of intracerebral processes?
We propose to revisit some modified states of consciousness: the dream, the near death experience and the terminal lucidity.
Dream
During our sleep we experience fictional scenes with such intensity that the brain areas involved in the perception of reality are reactivated.
Our brain allows us to experience surreal events where we can meet imaginary people, as if we enter another dimension.
According to Freud, the dream dives us into our unconscious, the study of our dreams allowing us to better understand its nature and its mechanism.
Jung claims that the creative resources of the unconscious are unleashed during our dreams widening the narrow views of our consciousness.
Everything indicates access to expanded skills and knowledge, unsuspected of our awake consciousness, as if our mental abilities were released.
NDE*
People whose brain was turned off keep their consciousness active if not expanded. They may report unknown facts some time occuring during their coma.
Near death experiences recall dreams, yet their unfolding conditions, amplitudes and impacts have no equivalent.
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Both are unconscious phenomena but during a NDE, the brain is very close to death or the patient is clinically dead.
It is no longer about fantastic scenarios but an access to an unlimited level of skills and knowledge.
An enhanced consciousness, an exit from one’s body, a 360°
vision, a complete review of one’s life, an encounter with deceased relatives or access to a larger level of knowledge are frequently reported.
The most striking example is the Pamela Reynolds one, who was operated on an aneurysm of the brain stem and whose her cerebral arterial circulation was interrupted more than an hour and her brain cools to 15,5°C.
When she awoke, she described in details her operation and the surgeon conversation with the cardiologist also present.
NDE are opposed to the materialistic theory limiting the consciousness to intracerebral physiological reactions.
Terminal lucidity*
People suffering from dementia, for many years or even their birth, could retrieve briefly their mental health just before dying, showing sometimes new abilities.
Hundreds of cases spanning several centuries have been
collected, for example:
- A woman with severe mental disabilites who was
never able to speak started singing for half an hour
before passing away.
Thus a serious alteration of brain function can be briefly corrected at the time of death.
Cases of terminal lucidity reinforce the hypothesis of a consciousness that can function with a disabled brain.
Summary
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NDE are opposed to materialistic theory limiting consciousness to intracerebral physiological reactions.
Severe alteration of brain function may be temporarily
corrected just before death.
4.3 Remembrance creation
Every day we receive thousands of information, sorted by the amygdala, useful information or high emotional event being preferentially retained.
The memory is created in the hippocampus in the form of a precise list of brain neurons involved in its development, represented by a unique spatio-temporal map.
We have 5 types of memory:
- The working memory manipulates in real time the
information needed for language, calculation, reflection and planning.
- The unconscious procedural memory is the memory of
know-how and motor skills.
- The perceptive, involuntary memory prints a trace of
perceived sounds, colours, images, smells.
- The semantic memory stores knowledge of ourselves
and the world, not related to lived events.
- The episodic memory records life-changing
experiences.
Moreover, we have no conscious memory of our early
childhood, this childhood amnesia is due to the progressive maturation of the hippocampus.
Summary
The memory is created in the hippocampus in the form of a precise list of neurons involved in its development.
We have 5 types of memory: working, procedural, perceptive, 39
4.4 Memory capacity
Is our physical memory sufficient in terms of its multiple roles and number of events, information and knowledge to record?
Digital
The storage capacity of our brain is estimated at 2,5 million Gigabyte* and that of a film from 90 min to 10, the brain can therefore memorize a total of 250.000 films (2,5 million/10).
The average life expectancy estimated at 80 years or 700.800
hours corresponds to 467.200 films (700.800/1,5).
The memory should therefore be doubled to record the film of a whole life in 2D (467.200/250.000).
This digital analogy is truncated, the total of data recorded being much higher:
- Our life takes place in a 4-dimensional space-time
environment,
- Our 5 senses are involved,
- Not to mention our emotions and thoughts.
Thus the totality of memories and knowledge accumulated
throughout life exceeds our memory capacity.
Neurobiology
Moreover, the brain is not limited to a biological library, therefore, the whole of its space cannot be allocated to the memory:
- We also have a working, procedural and perceptive
memory, all 3 of which require workspace.
- Only semantic memory (body of knowledge) and
episodic memory (significant events) retain long-term
information.
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- In addition to the memory, the brain has many other
functions: body management, environment perception
and analysis, manifestation of consciousness...
- A 3-year-old girl with her left hemisphere removed
had no particular disability and developed normally.
- A man with a brain reduced to 2 millimeters thick and
to 100g following hydrocephalus* leads a perfectly
normal life including academic studies.
Once again it appears that the brain storage capacity cannot cover our entire needs on its own.
We must admit that memory is at least partly relocated.
Summary
The brain storage capacity cannot cover all of our needs.
4.5 Conclusion
The number, variety, intensity of mental manifestations as sometimes their unfolding conditions exceed our limited
biological faculties.
The physical storage capacity of the brain is lower than the amount of information stored throughout the life.
At least partial relocation of the consciousness, the
unconsciousness and the memory is the simplest explanation for such prowess of our mind.
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