What is consciousness? Some define it as awareness, others as subjective experience. In science our awareness and ability to respond to our surroundings is something that can be studied, while our subjective experience is not. To state it another way, Philosopher Ned Block said that there are two kinds of consciousness (1): Access consciousness, which refers to information being processed in the brain (being conscious of something); and phenomenal consciousness, which he defined as subjective experience. I believe that both deserve attention and explanation.
To begin, I will discuss the scientific studies of awareness (consciousness). The highest state of consciousness scientists know about is that of being awake. This state is characterized by being alert, able to process sensory messages accurately, solve problems, control bodily movement, and so on (2). Even in the state of wakefulness, there is a range of consciousness. After eating a large meal, for instance, you may feel lazy and less alert. You may feel very alert while exercising, and moderately alert while attending a college class or working at a desk job.
A second state of consciousness is sleep. There are basically two kinds of sleep: slow wave sleep and REM sleep. Slow wave sleep is characterized by slowed heart and breathing rate, and larger, slower moving brain waves. When someone is in the state of slow wave sleep, they are much harder to wake because they are less responsive to outside stimuli. The second type of sleep is REM sleep, during which muscles become paralyzed, neurons fire at a high rate, and of course the eyes move rapidly (REM stands for “rapid eye movement”) (3).
A third and far more controversial state of consciousness is the hypnotic trance. People who are hypnotized are allegedly highly suggestible and not in full control of their actions (4). Very little is known about hypnosis, although most researchers see it as due to suggestibility, much like the placebo affect5.
There has been massive progress in discovering which parts of the brain are responsible for information processing and consciousness. In 1949, it was discovered that a part of the brain called the “reticular formation” was responsible for sending impulses to the thalamus and cortex (5).
Researchers stimulated the reticular formation in sleeping laboratory animals, and observed that this caused immediate and long lasting arousal in the cerebral cortex. Thus, the reticular formation controlled consciousness.
It has also been discovered that certain parts of the brain are responsible for the “feelings” we have. Philosopher Daniel Dennett (Who is also Co-Director of Tufts Center for Cognitive Studies) tells of a Neurosurgeon who was performing brain surgery on an epileptic patient. The patient had to be kept awake during the surgery, and the Neurosurgeon would stimulate parts of the patient’s brain, asking what sensation it caused (to make sure he was not removing anything absolutely vital). Oddly enough, one stimulation caused the patient to hear the Guns N’ Roses song “Outta Get Me” (6).
This brings me to subjective experience, or “phenomenal consciousness”. A popular concept in the philosophy of consciousness is the philosophical zombie (7): A hypothetical being who behaves as if it were conscious; yet does not have consciousness. A philosophical zombie would be, in crude terms, a computer made of meat. How can any theory of consciousness explain subjective experience? Why aren't we all just unconscious biological machines?
To answer this question, we need to understand what “qualia” are, and then understand what produces qualia. Daniel Dennett defines Qualia as “unfamiliar term for something that could not be more familiar to each of us: the ways things seem to us.” (8) A good example of a Quale (Singular form of Qualia) is the color red. What causes our awareness and visualization of that color? I think that when we see the color red, what is happening is that our eyes are picking up light and sending chemical and electrical signals to our brains that make us believe that we see red. (9)
This may be better understood with a thought experiment: Imagine that in the future, virtual reality video games are made which have no controllers, screens, etc.: They only manipulate your brain waves to make you believe certain things. Let's say that I created a virtual World War Two game. I manipulate the user's brain to make him believe he is seeing the beaches of
What is the difference between having a full-eye screen that displays the beaches of
For further reading, I highly recommend "Consciousness Explained" By Daniel Dennett.
Works Cited/References
1. http://www.bbsonline.org/documents/a/00/00/04/31/bbs00000431-00/bbs.block.html
2. See “Origins of the Mind” by Charles Furst, p. 76
3. http://library.thinkquest.org/C005545/english/sleep/stage.htm
3. http://skepdic.com/hypnosis.html
4. “Exploring Psychology” by David Myers, pp. 200-202
5. “Origins of the Mind” by Charles Furst, pp.76-77
6. See “Consciousness Explained” by Daniel Dennett, pp. 58-59
7. “Consciousness Explained” by Daniel Dennett, pp. 309-314
8. “Quining Qualia” by Daniel Dennett, accessed at http://ase.tufts.edu/cogstud/papers/quinqual.htm
9. This is a rephrased version of the explanation found on this website:
http://evanlouissheehan.home.comcast.net/~evanlouissheehan/Simplifying_Consciousness.htm
