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...
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.
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.)
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.
features of 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.
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.
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.
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
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.
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.
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.
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.
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.
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
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.
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.
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.
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.
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.
every page is elucidated by a short lecture on the subject: