The universe within
Every morning when the alarm clock rings, we become aware of our existence. Usually we first notice some vague sensations, like a feeling of warmth or cold, a tension in a limb, the heaviness of your awakening body or the babbling of the inner voice of thought… You open your eyes and see the room around you… We realize that we are here and now and that we will spend another day of living in our world in which we encounter our friends and family, our hobby's and work, our passions and routines, and where we experience our joys, fears and moments of sadness… Although this world, as we consciously experience it, feels like it is the real world out there, it only exists in the head of each of us. Without that experience however our lives would be meaningless. This inner world, being a mixture of representations of external situations and internal memory traces and evaluations is what I have called INTROVERSUM. From there we wonder what it is all about...
Conscious awareness thus is the stage for the drama of our lives, and this is so obvious that we seldom reflect on it. In this respect we are like travellers in a train, focussed on our destination while enjoying the view from the window but not interested in the transport company that makes this all possible.
Then, what is this real world out there that is represented in the consciousness of each of us? The best guess we can make is provided by science, thanks to which we can make reliable predictions and from which technology developed. Due to the common architecture that all human brains share, we have more or less the same kind of sensorial experiences (seeing, hearing, touching, etc.)
The brain is actually a large number of physical memory networks, in which our life experiences are wired. Each new situation is compared with previous experiences. Those earlier experiences determine how we will respond in actual circumstances. Our memories are the filters that attribute meaning to new experiences. We have separate memories for images, sounds, smells, memories, words, behaviours, emotions and many other sensations.
Some features of consciousness
Consciousness is a property of a living brain. Most of the activity of the brain remains unconscious however. If other organs than a brain could produce awareness remains unknown, but so far there are neither proofs nor indications. That is not a surprise if we consider the immense complexity of the mechanisms underlying consciousness in the animal brain.
Consciousness seems a central meeting point for the information brought in by all the senses. Several technical names have been suggested, like a theatre, a global workspace, a display or re-entrant networks. My own 'unified information field' is another example. Although naming doesn't explain anything, the model that it implies can shed new hypothetical light on underlying dynamics. The advantage of a fresh name can also be its semantic neutrality, making it necessary to make more efforts to explain and understand it.
Consciousness is based on a simultaneous parallel and serial processing mode. In every single moment we have lots of information to our disposal (we see, hear, smell and touch many details). Just imagine yourself watching a sunset or having dinner in a restaurant. But the composition of this informational display changes every second, passing from one meaningful item into the next.
Consciousness comes late. That means that the automatic reactions orchestrated by the brain, always precede consciousness. If I touch a hot stove, I have withdrawn my hand already when I feel pain.
At the same time consciousness often feels as if it is a means of control. Before walking to the coffee machine I decided to prepare a coffee, at least so it feels. Experiments of Libet and others proved the opposite and have put the question of free will under constraints.
The late appearance of consciousness makes one wonder why it should be there anyway. Does it have a function or is it just a accidental phenomenon due to underlying processes? This is still subject of a hot debate.Maybe the most striking feature of consciousness is its information richness in every single moment. This state is attained by qualia, the basic elements of experience like the colour green, the sound of the voice of my lover, or the smell of a flower. These coexist in a meaningful way, thus bringing together many aspects of our lives.
Consciousness can be more or less intens. Its contents vary from moment to moment. We can recognize different levels of awareness:
— 'Core consciousness' we probably share with many other animals. It helps us to experience in real time mode the interaction between the organism and its environment.
— 'Extended consciousness' helps us to map the relationship between these experiences themselves and implies input from long-term memory. That makes it possible for previous experience to direct future behaviour.
We must distinguish between what consciousness IS and how we experience it. Thus we introduce a dualistic position: publically accessible objectivity (the res extensa) and private, personal experience, a view on the world out there from a delimited part of the res extensa (the body, itself a part of the res extensa ). The relationship between consciousness and its contents implies dualism, as knowledge is always knowledge 'about' something. The function of consciousness is the creation of an internal, highly integrated model of the environment, the self and their mutual relationship. The anatomy and physiology of the brain make this clear. Our brain is an on-board computer that takes in signals from the social and physical environment, including the body and orchestrates appropriate behaviour. How this vast amount of information is integrated, leading to subjective experience, is still unexplained. What is clear however is that these processes serve an organizing and filtering function. Without such unification our brain would become overwhelmed by massive electric action potentials, thus incapable of attributing meaning to the many information flows.
An important step is the translation of neural firing patterns into qualia. Qualia are qualities of experience, such as color, shape, smell, sound, pain, anger and other sensations, contributing in varying proportions to any moment of consciousness. They make sure that we can differentiate within and between our experiences, making them highly informative. How neural firing patterns (and other relevant neural correlates of consciousness) give rise to qualia can be considered as the transition point of the objective to the subjective. Partly because physical and biological processes are described by scientific models and language concepts, being hypothetical but workable representations of reality themselves, we should not expect too soon a satisfying and intuitive throbbing answer to the question what is the exact relationship between neural firing patterns and subjective sensations like the soft yellow color or the sweet scent of lilies of the valley. Qualia are probably complex phenomena, of which the contributing processes still have not been traced through reduction. Some argue that even in the future this will stay impossible. This pessimistic view comes from philosophy, a field that has proven itself to be better at questioning than explaining phenomena. But even if qualia are emergent properties of a larger system, detailed knowledge of the elements of such a system might still be the key to understanding them.
I consider consciousness as an epiphenomenon (or rather a different manifestation) of a complex neural information processing activity. In this process, large amounts of information coming from the sensory periphery are encoded, each with respect to their receptive function. This allows information flows on light frequency (resulting in color quale), on molecular composition (resulting in smell quale) and on air pressure fluctuations (resulting in noise quale) to be kept apart. This encryption takes place in the primary cortices. The encoded information streams are then combined into an upward hierarchy and modulated by feedforward and feedback loops. Eventually they are integrated into a unique field or master network (Edelman's 'dynamic core'), fueled by slave dynamic networks, without losing their individual sensorial coding characteristics. Therefore, it is a very intense, intrinsically associated network, modulated by a variety of lower hierarchical levels. How the different encodings (e.g. those that correspond with the yellow color and those with the scent of lilies of the valley) 'understand' each other, remains unclear. About their temporal associations we know now that these are produced by special synchronization processes (binding). To what extent qualia arise at the level of individual neurons or at network level is still a mystery. More about this in the section on Theories of consciousness.
The processes that give rise to subjective experience are energy expensive. A subtle mix of neurotransmitters in the brain, particularly acetylcholine, noradrenalin and serotonin, determines the activation of the thalamus, which as a spider in a neural web communicates incoming and outgoing information flows with all parts of the brains. When the level of these energizers in the brainstem is reduced, we fall asleep. The thalamus then falls back in the standby mode, generating a specific rhythm of action potentials. These are measurable at the cortex (theta waves), which then has become less active itself.
During dream sleep there is more activity in some parts of the cortex and the limbic system. Increasing levels of acetylcholine in the brainstem modulate this process. The prefrontal cortex, however, remains closed, partly due to low dopamine production. As a result there is no conscious planning activity.
The content of this website
On the next page will follow some information about brain circuitry underlying consciousness. Especially Gerald Edelman, Francis Crick and Christof Koch gave some very important clues.
Then we move on to some philosophical aspects, like the dilemma of dualism and some epistemological problems. The questions about consciousness, what it is and how is arises, have puzzled philosophers for ages, but their intellectual, introspective efforts have not provided satisfying answers so far. But philosophers are particularly goods at asking the right questions, so that is what we are going to look at.
In the section that follows some of the most influential theories of consciousness are discussed. Recent scientific progress in biology and especially neuroscience gives new hope and new points of departure. More people than ever seem to be interested in the subject, which also could lead to more efforts to tackle the problem. After all, we are all specialists, as we all are the owner of a private consciousness, which I have called: introversum.
The final pages include an account of my own view on the subject and a forum at which I would love to exchange ideas with all of you that share this interest. Reflecting the impermanence of reality, I hope the site will stay under constant revision and updating, not at least by constructive critics and new input from readers as well as from developing insights based on science.
With regard to the last, in science - as opposed to dogma and religion - we build on a body of knowledge about relations between aspects of our social and material world. Words, sentences and theories in science are like cells in our animal bodies: they only live as long as they are useful. This unselfish mentality helps the process. Science is not for egos.
Finally, every page is elucidated by a short lecture on the subject:
