Review: 

• consciousness as a continuum
• biological rhythms
• circadian rhythm

Consciousness can also be defined as 'awareness of self' . Next week, if we have time, we will see a video on consciousness in animals. However, while animals may be more aware of what is going on around them and of their bodies than scientists previously realized, we do not have much evidence that they are self  aware.

(For more information about sleep and links to more sites than you need for this course, click on SLEEP.)

This is what you do need to know about sleep:

1.  There  are four stages of sleep:

• Normal waking consciousness:  high frequency brain waves, 'Beta' brain wave patterns, aware of surroundings, able to interact with environment
• Relaxed wakefulness (eyes closed) brain waves slower and more rhythmic (some Alpha brain waves).
• Stage One of sleep: theta waves and some small alpha brain waves, but more irregular. Very light sleep; often person doesn't even recognize he/she has been sleeping  ('Just resting my eyes!). Slight drop in core body temperature.
• Stage Two: appearance of 'sleep spindles'  and 'K complexes in EEG brain waves, body temperature dropping lower. If person awoken, aware that he/she has been sleeping but still relatively easy to waken. (As a person 'drops' into this stage, they may jerk or startle once involuntarily; this is called a 'hypnic jerk'. 
• Stage Three: initial appearance of some long slow Delta waves, further loss of consciousness
• Stage Four: Almost all Delta waves, deepest sleep (pure oblivion), hardest to awaken (may be confused). Occurs about an hour after first falling asleep. When a person is exhausted due to physical exertion during the day, he or she will spend more time in this stage of sleep, suggesting that Stages 3 and 4 are needed for physical restoration.

After reaching stage four during the initial part of a night's sleep, the individual moves back up through the levels to stage one, a cycle of about 90 minutes that repeats itself. As the night goes on, less time is spent at the deep levels and more in Stage One and Two.

2.  There are two states of sleep:

• REM sleep: Rapid eye movements and other signs of physical and emotional arousal. An EEG of the REM state has an pattern more like waking than sleeping. Usually associated with dreaming (as reported by person when awoken from REM sleep). During this stage, the major muscles are not able to move. Usually occurs during periods of Stage One  sleep, although not the first Stage One period of a night's sleep. Length of time spent in REM sleep increases over the course of a night's sleep and a person spends more time in REM sleep during times of stress.
• NREM (nonREM) sleep: no indication of eye movement. Can occur during any of the four stages of sleep, but most common in stages Two, Three and Four. Dream-free about 90% of the time. Major muscles are not paralysed in non-REM sleep. Sleep-walking and sleep-talking as well as night terrors occur during stage three and four, in NREM sleep states.

Humans (and mammals) cycle through REM sleep and deep sleep in approximately 90 minute cycles. REM sleep may related to the development and maintenance of the neocortex. Even in the womb, infants have REM sleep and then have periods of REM about half of the 16 hours of sleep per every 24 hour cycle. This is a time of tremendous growth for the infant's cortex and REM may be associated with that growth spurt.)

Total sleep deprivation vs REM sleep deprivation:
    When a person is constantly woken up as they enter REM sleep, there are no lasting psychological or health affects, although material learned before sleeping is not retained well if REM sleep is not allowed to occur, suggesting that REM assists in consolidating long-term memories. When the person is then allowed to sleep uninterrupted,  he/she makes up for the lack of REM by spending more time in that state ('REM rebound')  While lack of any of the non-REM stages of sleep doesn't appear to have lasting or severe effects, the lack of sleep altogether can be fatal. However, unlike REM sleep deprivation, overall sleep  deprivation cannot be 'made up'. Even after being awake over 200 hours, a DJ who tried to stay awake for days only slept 13 hours!

Thanks to the invention of the electric light, most people these days do not get all the sleep they need: while people averaged about 10 hours a hundred years ago, now we are down to an average of 7 hours!  And in some cultures, adults as well as children nap during the day, nd researchers find that although some people report feeling groggy after a daytime nap, most report both better mood and performance after napping.  (Unfortunately our industrial culture does not allow for this sort of midday break for most of us.....)    

All people dream, (and, possibly, all mammals, as they too have REM sleep and behave as if they were dreaming at those times I see my dog quietly yipping as her paws twitch in a dream chase of a rabbit? or squirrel?)  although not everyone remembers his/her dreams. The degree to which dreams are considered a valued part of a culture affects how likely people are to remember their dreams. In cultures that emphasize the importance of dreams, dreams may be considered to be messages from spirit guides from another world, important channels to one's inner voice, representative of alternative realities, or even God's way of speaking to us. In our busy culture, many people can rarely recall their dreams; the demands of their daily life immediately interferes with their awareness of the dream just ended, preventing the dream from being 'saved' in long term memory.

Dreams occur most frequently during REM sleep (80% to90% of REM sleep time) and REM sleep dreams are the most vivid and emotional of all dreams. Dreaming is reported less frequently (only about 10% of the time) when people are woken from non-REM sleep and the dreams they describe are more like thoughts than experiences; less emotional and 'lively'.

We discussed some of the theories of dreaming:

•  Psychodynamic Theory: Freud believed that dreams were a means of fulfilling forbidden  and unconscious wishes and desires, but that the true meaning (latent content) of the dream was disguised in symbols (manifest content). He felt the images in dreams were symbols that reflect internal conflicts and subconscious motives such as socially unacceptable desires. Dreams serve as a sort of 'safety valve' for the pressure of these primitive impulses, a way of acting them out without violating society's rules.
• Activation-Synthesis theory: Hobson and McCarley argued that dreams are a byproduct of the brain's automatic activities during sleep. They said that part of the brainstem (pons) sends out activating messages in random patterns to the cortex, stimulating sensory circuits. The messages from the brain to the body are blocked, so no movement results, but the sensations of  movements and perceptions are then accounted for by the 'synthesis' (putting together) of various stored memories that 'explain' the sensations. In fact. according to this theory, there is no hidden meaning or logical reason to dreams; they are simply the result of random cells firing in the pons and sending both inhibitory and excitatory messages to the cortex.
• Calvin Hall studied dreaming in many cultures and found evidence that culture as well as aspects of daily life were reflected in dreams. He also found certain common elements, regardless of culture, in dreams from all over the world. While he saw symbolic content in dream images, he felt that the symbols directly expressed their meaning, rather than disguising it as Freud proposed.  
• Many current researchers ascribe to the theory that dreams are extensions of waking life, reflecting the events, feelings, thoughts, etc. of our daily lives. Everyday events, people and places are often a part of our dreams, though rarely without non-logical distortions and juxtapositions.That we replay our daily experiences in our dreams is shown by the  example in which  experimental subjects, after wearing red goggles for a week, reported seeing the world in  'red' colors in their dreams. And research has shown that culture plays a role in shaping the content of our dreams; that people in violent cultures often have violent dreams, while people who live in more peaceful societies do not. The book give these examples: Japanese college students rarely dream about strangers or animals whereas they are fairly common in American college students' dreams. This may reflect that pets -and contact with animals in general - are relatively rare in Japan, and the culture's homogeneity and value of collectivity may mean that other Japanese are not perceived as 'strange'.
• Others feel think that dreams represent another source of information about our lives or are a way of working on problems, fears, and concerns. Many people follow this advice when trying to make a difficult decision: 'sleep on it!' They may wake to find an issue resolved or decision made during the night.
• Dreams also express creativity in their original juxtapositions and unique visions. Ernest Hartman, of Tufts University, a psychiatrist , theorizes that dreaming allows us to explore the complex web of interconnections of brain cells (without the interruption of new incoming sensory data) in new ways, making broader connections and new associations. This may explain the importance of dreams in both creative inspiration and also problem solving during dreams. A designer I know comes up with some of his highly original compositions in his dreams.

Think about your own dreams (if you can remember them!) Which theories best match your own experience? Most likely you will find different theories  are needed to explain or understand different dreams....

Video: "Dreams: the Theater of the Night". Reviews and explains theories of dreaming, illustrates methods for studying dreams, and discusses possible meanings of dreams, including the activation/synthesis and psychoanalytic, but also some other possibilities, such as the idea that maybe dreams are just part of a 'computer de-bugging program', processing the day's data, removing unimportant or harmful memories and consolidating the important ones, preventing brain 'overload', or that REM sleep could be like a 'pilot light' for the brain, preventing  the brain from lapsing into permanent unconsciousness, and priming it to be ready to go upon awakening.
The video also raised the issue of lucid dreaming, in which people can learn to control their dreams. 

• The film also demonstrated various sleep disorders and the fact that  we move around frequently during sleep (stages 2, 3, 4) each night.

 I gave out a copy of a magazine article: "What Dreams Are Made Of" (NEWSWEEK, NOV 8, '99) which cites some of the research supporting aspects of both the activation-synthesis theory and psychodynamic theory. The handout, a copy of a report out just last year on the latest research in dreaming, offered some additional information on the  biological processes of dreaming. New information shows that while REM sleep occurs during the part of sleep where dreams are most likely to occur, it is not the cause of dreams, nor is it essential to dreaming. Rather, it is the state most conducive to dreaming. Research done by PET scans shows that if the pons (which sends out the messages to the brain which trigger REM) is so damaged that REM sleep does not occur, people still dream. On the other hand, if there is damage to some of the higher areas of the brain (especially areas having to do with emotions, memory, and processing of visual information such as object recognition as well as the areas associated with motivation), there will still be REM but no dreams. During dreams, the rational regions of the brain are deactivated, which explains the illogical aspects of dreams,  but there is a lot of activity in the sensory-motor cortex and the motivational areas as well as the visual areas mentioned. The reason the motor activity doesn't result in a lot of moving around during dreams is due to the fact that the activating messages to the muscles are blocked in the brain stem.

For web-based information about dreams, click on the dream portion of the  Dreams and Lucid Dreams

Sleep disorders:

• Insomnia: problems going to sleep., staying asleep and  waking too early resulting in sleep deprivation. We discussed a number of suggestions and techniques for dealing with insomnia. Taking sleep medication (or an alcoholic drink) to deal with insomnia is not suggested; they may help one drop off to sleep, but they disrupt the needed cycles through the various stages and levels of sleep, and also may create dependency.
• Sleep apnea:   a disorder in which a person stops breathing for short period, waking in a panic from oxygen deprivation, and then falling back asleep again. Repetition of this cycle hundreds of times in a night creates sleep deprivation and has been shown to increase the risks of stroke, heart disease and other health problems, but the condition is seriously under-diagnosed. An obvious symptom is heavy irregular snoring. Treatment consists of wearing a mask (while sleeping) that maintains a positive air pressure in the lungs.
• Narcolepsy: 'Sleep attacks', in which a person falls immediately asleep in the middle of normal waking activities. His/her muscles go slack and REM sleep begins immediately. 'Sleep attacks' are usually triggered by pleasurable events. This has been shown to be due to a defect in a single gene (shared by narcoleptic dogs!) and, while incurable, can be treated to some degree by the use of stimulants and afternoon naps.
• REM sleep disorder: This is a disorder in which the person's muscles are not immobilized during REM sleep. (The video showed one man with this problem beating on his pillow while dreaming.   Pity his wife!)
• SIDS (Sudden Infant Death Syndrome): This is apparently a type of sleep apnea in infants whose sleep/breathing systems are not yet fully coordinated and the baby doesn't respond actively enough to the sudden lack of oxygen. The 'Back to Sleep' training program has reduced SIDS by up to 50%.
• Parasomnias: There are a number of other sleep disorders that include sleepwalking or talking, night terrors, and enuresis (bedwetting) which are associated with level 3 or 4 sleep. They are most common in young children, but are more common in adults than generally realized (probably because the topics are embarrassing).

PSYCHOACTIVE DRUGS: substances that affect our nervous system, altering consciousness and awareness, moods, feelings, and thoughts.
After caffeine, nicotine is the world's most widely used psychoactive drug, and, according to the Surgeon General, is the single largest avoidable cause of death in the United States today. Alcohol directly  kills only about 1/4 as many people as nicotine, but because it is significantly involved in so may medical, social, emotional legal, job-related and personal problems, many consider it to be the most dangerous and costly of all legal and illegal psychoactive drugs. 
 For the section on altering consciousness with both legal and illegal psychoactive substances, study the Table on pages 220-221,  and know which drug combinations are dangerous because of their interactive (rather than additive) effects. Also know the difference between physical addition (in which a person develops a physical dependence on the drug that includes a tolerance for it and withdrawal symptoms when usage stops) and psychological addiction, in which use and abuse is not due to physical dependency but is a habitual pattern of drug-using behavior. One can have a 'habit' and/or a dependence.