Peels

Because the primary function of sleep is not for rest, tiredness does not always lead to sleepiness. To fall asleep, you need to meet three conditions: lowering the sensory input level below a threshold; stop motor output; and lowering the activity of the conscious brain below a threshold. It is usually easy to meet the first two. However, the third one is sometimes hard to satisfy, especially when under high stress. As DV8 2XL put it, "Mostly it is stress or worry that causes classic insomnia."

I agree. I think that was what Freud tried to point out in The Interpretation of Dreams. "Dreams a brief insanity, and insanity a long dream" (Schopenhauer in Freud).

All conscious forms are composed of neurons that are not themselves conscious. Consciousness occurred, when many different kinds of neurons are connected in some ways. To solve the consciousness puzzle, one needs to answer why, when and how consciousness was evolved. Therefore, in my opinion, the first step is to figure out the transition point from non-conscious to conscious.

Although some studies using CT scan and MRI have demonstrated quite remarkable differences between a normal brain and schizophrenia brain, some studies also indicated that some brains with similar differences have no schizophrenia. The chemical imbalances theory is also only a belief/theory. If interested, see the debate between Pfizer and MindFreedom: http://www.mindfreedom.org/mindfreedom/pfizerlies.shtml This is why the diagnosis for schizophrenia is still based on the SYMPTOMS – what the person says and what the doctor observes, and judged by the DSM-IV (in US), not by checking brain chemical level or other lab tests, such as a CT scan, MRI, or blood tests etc. (these tests may be done to rule out other conditions that can cause symptoms similar to schizophrenia.). The fact is that we don't know what level of brain chemical is normal yet.

Francis Crick, in his book: The Astonishing Hypothesis, pointed out that "you, your joys and your sorrows, your memories and your ambitions, your sense of personal identity and free will, are in fact no more than the behavior of a vast assembly of nerve cells and their associated molecules". As Lewis Carroll's Alice might have phrased it: "You're nothing but a pack of neurons." As we know, all life forms are composed of molecules that are not themselves alive. Therefore, to define the lowest level of living life possible, there is general agreement that a localized molecular assemblage should be considered alive if it continually regenerates itself, replicates itself, and is capable of evolving. My original question of consciousness was sprung from the similar thought. So, what I would like to know is that by adding which function (both necessary and sufficient), could we change a non-conscious living life to a conscious living life? For instance, in my opinion, language and self-awareness (I classify them as higher level of consciousness) are sufficient but not necessary to define consciousness.

A person without cortex, I think, will be in a coma state.

viruses? DNA? Atoms? --- Are they conscious at all? I am really confused about the definition of consciousness while I google around about this topic.

What is the lowest level of consciousness possible?

Hi pljames, I am not working in the mental health field, not even life science field. Like everyone responded, it depends on how you define "normal". For a given definition of "normal", any thing out of it will be labeled as "un-normal". Many mental illnesses are examples of this, including schizophrenia. My guess is that you want to debate about schizophrenia. So, what is your viewpoint?

I agree with gnpatterson to use close-packed hexagonal arrangement. I think the answer is 525.

Try these two links: Association for the scientific study of consciousness (ASSC) http://assc.caltech.edu/index.htm Science & Consciousness Review http://www.sci-con.org/articles.html

I agree with mmalluck. Anyone who read some articles about EEG biofeedback or neurofeedback would know that the electrical state of the brain can be changed by controlling one's own thought to particular brain states.

I googled a little bit earlier this year about this topic. Among many articles read, I highly recommend this review article to anyone interested in this topic about Prof. John Lorber's work: "Exploding the 10 percent myth" from Science & Consciousness Review (September, 2004) http://www.sci-con.org/articles/20040901.html

Yes and No, depending on which part of sleep you are talking about. I think that sleep could be divided into two parts: necessity and luxury. Necessity is the part of sleep that you have to have; and the luxury is the part that you could have it and not have it. Just like after dinner then have some dessert. The dinner part is necessary for your health, however, the dessert part is only for luxury. You can reduce this luxury part of sleep any time you want.

"If the many hours of sleep accomplish nothing, it is the greatest mistake nature ever made." quoted from Dr. Allan Rechtschaffen, U of Chicago

As I known, even scientists and researchers in this field still claim that "the mechanism is as yet unknown", referring to Nocturnal erection (quoted from the article you suggested, Lue, et al, Physiology of Penile Erection at http://www.duj.com/Article/Lue.html). It seems to me that you mixed up Skeletal muscle with smooth muscle. First, it is true that we are almost completely paralyzed in REM sleep due to the main skeletal muscle lost muscle tone. However, as my understanding through reading, our smooth muscle, cardiac muscle (found only in heart), and even many small skeletal muscle (like eye muscles) are never paralyzed in REM. This is why we have this rapid eye movement during REM sleep. Second, when talking about muscle of penile erection, we are referring to the smooth muscle, not skeletal muscle: "The penile erectile tissue, specifically the cavernous smooth musculature and the smooth muscles of the arteriolar and arterial walls, plays a key role in the erectile process." (quoted from the article you suggested, Lue, et al, Physiology of Penile Erection at http://www.duj.com/Article/Lue.html, (emphasis added)). Therefore, your statement of "the penis IS paralyzed during REM sleep" is untrue, as there is no skeletal muscle in the penile.

What is a nervous breakdown? In the Middle Ages, it was called melancholia. In the early 1900s, it was known as neurasthenia. From the 1930s to about 1970, it was known as a nervous breakdown. "Nervous breakdown" is a term that the public uses to characterize a range of mental illnesses, but generally it describes the experience of "snapping" under immense pressure, mental collapse or mental and physical exhaustion. Nervous breakdown" is not a clinical term. There is no psychiatric definition of a nervous breakdown, and it has nothing to do with nerves. "Nervous breakdown" is an inexact and unscientific term that is no longer used in psychiatry. The diagnosis that most closely resembles what the public calls a nervous breakdown is major depression. The mental illness known as a "nervous breakdown" may also be something like panic attacks, schizophrenia, post-traumatic stress disorder or acute stress disorder. from http://people.howstuffworks.com/question653.htm

"Besides the heart and lungs, another part of the body is not paralyzed during REM sleep: the penis. Normal men always have an erection during REM sleep. When one of my colleagues was asked, for the umpteenth time, where dreams come from, he answered, 'I don't know where they come from, but I think that the erect penis serves as the antenna to receive them.' This doesn't really violate the rule about paralysis during REM sleep, since erections are not caused by muscle action but by blood engorgement. Since there is usually a REM period right before waking, men often wake up with an erection. In women, other sleep researchers have found that there is increased vaginal blood flow and clitoral engorgement during REM sleep. The increase in blood flow in both men and women during REM sleep is probably an incidental effect of the activation of the part of the autonomic nervous system that controls heart rate and other involuntary body functions. Penile erection during REM (called nocturnal penile tumescence, or NPT) is sometimes misunderstood, usually because the sleeper or his partner thinks the erection signifies that the dream is about sex. This is not the case. No matter what the dream is about, REM sleep will produce an erection in any man who is not impotent for physical reasons. A patient was referred to me because she was concerned that her husband had an erection every night, and she thought he must be dreaming about sex with another woman. She worried that this was a reflection of a real affair. She was very distressed, but I assured her that, barring any other evidence, she should put her mind at ease. The erection is almost never associated with erotic dream content. Even newborn males have erections during REM sleep. Once, through an error in the hospital billing office, over 100 women were billed for an NPT test. When many of these women called to ask about the NPT test on their bill we had to suffer the embarrassment of telling them about the test and our mistake. The worst moment was explaining this to a patient who was a nun." Quoted from William C Dement, "The Promise of Sleep", 1999.

Inventor Kurzweil Aiming to Live, not 100 years, but Forever - Immortality! http://www.cbsnews.com/stories/2005/02/13/tech/main673726.shtml

When we talk about the bladder controll thoery, we are talking about REM sleep. It is possible that one has a need to go to toilet without erection if woke up from NREM sleep.

I just noticed that my dog also has this "Nocturnal penile tumescence" sometimes in the morning.

This has nothing to do with impotence! It caused by attention to urinating, and reflects a change of neurotransmitters after wake up from REM sleep.

Men do need more effort to initiate urinating, and usually lost erection quickly during urine discharging.

Thanks Newtonian for your link. To solve this puzzle, two questions need to be answered. First, what is the cause of the penile erection in REM sleep? Second, what is the function of the nocturnal erection? The article from this link gives a theory about the first question only. I'll quote some parts from this article "The male sexual response reflects a dynamic balance between exciting and inhibiting forces of the autonomic nervous system within the penis and throughout the CNS. The sympathetic component tends to inhibit erections, whereas the parasympathetic system is one of several excitatory pathways… Switching off the activity of the sympathetic nervous system enhances erections. Nocturnal erections are a good example of this. Nocturnal erections occur primarily during rapid eye movement (REM) sleep, the stage in which dreaming occurs. During REM sleep, sympathetic neurons are turned off in the locus coeruleus, a specific area of the brain stem. According to one theory, when the sympathetic nervous system is at rest, proerectile pathways predominate and allow nocturnal erections to occur." However, the theory did not explain why our brain has to shut off the sympathetic nervous system in REM sleep. The odd part that I noticed is that many other articles give an opposite result. They claim that sympathetic-nerve activity increased significantly during REM sleep (NOT "switching off"), which is in agreement with the observation of increased heart rate and blood pressure. Switching off the activity of the sympathetic nervous system will also cause a big problem to the urinary system. As we know, under normal conditions, the bladder and the internal urethral sphincter primarily are under sympathetic nervous system control. When the sympathetic nervous system is active, it causes the bladder to increase its capacity without increasing detrusor resting pressure (accommodation) and stimulates the internal urinary sphincter to remain tightly closed. The sympathetic activity also inhibits parasympathetic stimulation. When the sympathetic nervous system is active, urinary accommodation occurs and the micturition reflex is inhibited. This means that without inhibiting from sympathetic nervous system, the bladder will hold less pee and the internal urethral sphincter will be out of control. Any comments?