The term consciousness has several different meanings.

In colloquial language, it denotes being awake and responsive to one's environment; what some call reactivity. This might contrast to being asleep or being in a coma.

Philosophers distinguish between phenomenal consciousness and psychological consciousness.

Table of contents
1 Phenomenal consciousness
2 Psychological consciousness
3 Consciousness and language
4 Consciousness and chemistry
5 Consciousness and memory
6 Further reading
7 External Links

Phenomenal consciousness

There is, on the view of very many philosophers, one mental function that accompanies some, or perhaps all, mental events, namely, consciousness. In a philosophical context, the word "consciousness" means something like awareness, or the fact that the mind is as it were directed at something or other. (That sounds more like a definition of that philosophical term "intentionality" often laymanified as "aboutness".) So when we perceive, we are conscious of what we perceive; when we introspect, we are conscious of our thoughts; when we remember, we are conscious of something that happened in the past, or of some piece of information that we learned; and so on.

In this philosophical sense of the word "conscious", we are conscious even when we are dreaming; we are conscious of what's happening in the dream. But sleep researchers believe there is a sleep stage that happens, called "deep sleep", in which apparently we are not conscious of anything in any sense. No mental processes that involve consciousness in an ordinary or in a philosophical sense are going on. So deep dreamless sleep is an instance in which one is alive and one's brain is functioning, but there are no mental events occurring in which there is any element of consciousness.

Modern discoveries on consciousness are based on study of consciousness states and the deficits caused by lesions, stroke, injury, or surgery that disrupt the normal functioning of our senses and cognitions. These discoveries suggest that the mind is a complex structure of various localized functions held together by a unitary awareness.

There has been some debate about the following question: Must one be conscious, in the philosophical sense, whenever a mental event occurs? For example, is it possible to have a pain that one does not feel? Some people think not; they think that in order for something to be a pain, one has to feel it or be aware of it. Similarly, if anything is a thought, then one has to be aware of that of which one is thinking (indeed, that seems nearly a tautology); if there is no consciousness, no awareness, of anything at all, then one is not thinking. Philosophers ask: Do mental events necessarily involve consciousness?

Suppose we answer "No." Then of course what we'd be saying is that there are some mental events that do not include an element of consciousness. These events are going on even though we aren't aware of them. In other words, part of the mind is unconscious. Cognitive scientists believe that many cognitive processes are unconscious in this manner; we are aware of only some of the stuff that's going on in our minds. Some may even view consciousness as an emergent phenomenon, somehow arising from a hierarchy of unconscious processes. These are fairly recent views, made popular only after Freud.

The complementarity of consciousness has parallels with the nature of quantum theory. This has prompted quantum models of consciousness.

Psychological consciousness

Psychological consciousness refers to a closely interrelated set of features. Julian Jaynes lists these features as:

1. spatialization - having an internal mental 'space' in which hypothetical events can 'happen'. It is impossible to think of any events occurring in time without spatializing them, usually on a timeline running from left to right. People who are not conscious (eg, in a hypnotic state) are incapable of thinking about time or putting things in a time-ordered sequence.

2. analog I - being able to see 'in' one's spatialized mind what one would 'see' if one were in a certain situation. For example, if a person comes to a fork while walking through a forest, they can 'see' 'in' their mind what they would through their eyes if they took either of the paths. It's based on this information that they can decide to take one path (perhaps more scenic) over the other.

3. analog Me - the 'I' is the subject performing actions, through whose eyes we 'see'. The 'Me' is an object 'seen' in its entirety. The 'I' is the first-person view in computer games while the 'Me' is the third-person view, behind the main character. One can often 'see' oneself performing actions 'in one's mind' as if one were 'outside' of one's own body.

4. excerption - the taking of a small aspect of something to stand for that whole thing. No one thinks of their city by imagining every house, every streetcorner and every sewer. One takes something, perhaps the skyline or city hall, and lets it stand for the whole thing. The same occurs for everything. Recalling one excerption after another by a chain of associations is what constitutes 'reminiscence'.

5. conciliation - something similar to assimilation of knowledge to fit a schema but done 'in' a conscious mind.

6. narratization - the constant unnoticed activity of thinking of one's life in terms of stories, in which one is the star character.

See also:

Consciousness is generally regarded as comprising abilities such as self-awareness and the ability to perceive the relationship between oneself and ones environment. A thing that is conscious uses the term "I" to refer to itself. So far, the only beings believed to be conscious are human beings.

Human consciousness is generally regarded by most people as an self-evident directly perceived entity. However, consiciousness has been a great problem for scientists and philosophers.

In particular, philosophers have asked "how do we know we are conscious?" and "how do we know other people are conscious?". It turns out that these are difficult questions, both to formulate accurately, and to answer.

One question is to what extent other primates, whales and dolphins, or grey parrots have consciousness. These issues are of great interest and controversy not only to scientists, but also to animal rights lawyers.

In the past the origin of consciousness was looked for in a soul separate of the body. This idea developed in many cultures. Some of these conceptions were first developed in ancient Greece, and later adapted to Christian ideas.

Today human consciousness is understood by many scientists as a function of the brain. This realization is based on the observation the fact that consciousness can be affected through chemical substances working in the brain and that often mental disorders cause changes in consciousness. Human behavior is affected by conscious and unconscious processes (assumed to be displaced consciousness contents and instincts), whereby the dividing line is to be drawn with difficulty.

Experimental psychology and developmental psychology, which are concerned with the learning behavior of infants (e.g. Elizabeth Spelke, Stephen Pinker), point to an early developing consciousness.

Usually most consciousness awareness is lost during sleep. However, some people can activate this awareness by using lucid dreaming techniques.

Consciousness and language

Because of the fact that humans can express themselves by language, unlike all other animals, it is tempting to equate language abilities and consciousness. There are however speechless humans (infants, Kaspar Hauser, accident victims), to who consciousness is attributed despite language lost or not yet acquired. Also consciousness does not change by the acquisition of a new language. Consciousness is therefore one of the conditions for the language acquisition; missing language ability is however no reference to missing consciousness.

Here a distinction must be made between language abilities and language authority: language authority is for example present with mute ones quite (see bearing language). Language is the substantial means of humans to give expression to the experience of consciousness. Other forms are artistic, such as music, dance, painting and sculpture.

Consciousness and chemistry

Consciousness-changing chemicals human consciousness can be affected by medicines. Sleeping drugs (e.g. Midazolam = Dormicum) are used, in order to bring the brain from the awake condition (conscious) to the sleep (unconscious). Wake-up drugs (e.g. Anexate) reverse this process. Many other drugs (such as heroin, cocaine, LSD, MDMA) have a consciousness-changing effect.

It is generally believed that general anaesthetics work by suppressing consciouness.

Modern brain research assumes that consciousness expires at brain death.

Consciousness and memory

Consciousness is closely connected with the ability of memory, since even after temporary consciousness loss the identity of the individual remains.

Further reading

  • How the Mind Works, Stephen Pinker.
  • Consciousness Explained, Daniel Dennett 1991
  • Consciousness: An Introduction, Susan J. Blackmore, 2003.
  • The Alex Studies: Cognitive and Communicative Abilities of Grey Parrots, Irene M. Pepperberg, 1999.

External Links