Chapter 10 consciousness

rapid eye movement (REM) sleep

, or rapid eye movement (REM) sleep During this stage of sleep, the sleeper's eyes move rapidly back and forth under the closed lids. (The other stages of sleep are known as non-REM, or NREM, sleep.

paradoxical sleep

A paradox is an apparent contradiction. REM sleep is paradoxical because it is light in some ways and deep in others. It is light because the brain is active and the body's heart rate, breathing rate, and temperature fluctuate substantially. It is deep because the large muscles of the body that control posture and locomotion are deeply relaxed. Indeed, the nerves to those muscles are virtually paralyzed at this time.

neurocognitive theory

An alternative view, known as the neurocognitive theory, is that dreaming is simply a kind of thinking, similar to daydreaming or mind wandering, that occurs under these conditions

sleep apnea

Apnea means "no breathing." Many people have occasional brief periods without breathing while asleep. People with sleep apnea, however, fail to breathe for a minute or more and then wake up gasping for breath.

insomnia

Insomnia means "lack of sleep." More specifically, insomnia is not enough sleep for the person to feel rested the next day

lucid dreaming

Lucid dreaming is another example in which part of the brain is awake and another part asleep. Someone having a lucid dream is aware that it is a dream. Lucid dreaming occurs during periods of increased activity at 40 Hz (cycles per second) in the frontal and temporal cortex, with less arousal in the rest of the brain

polysomnography

Sleep researchers combine an EEG measure with a simultaneous measure of eye movements to produce. test to monitor brain waves, muscle tension, eye movement, and oxygen levels in the blood as the patient sleeps.

sleep talking

Sleep talking is a common experience that ranges from a grunted word to a clear paragraph. Many people talk in their sleep more often than they realize because they do not remember sleep talking and usually no one else hears them. Sleep talking is most common during stage 2 sleep, but it occurs in all stages

vegatative state

Someone starting to emerge from a coma enters a ________, marked by limited responsiveness, such as increased heart rate in response to pain.

Melatonin

The suprachiasmatic nucleus exerts its control partly by regulating the pineal gland's secretions of the hormone melatonin, which is important for both circadian rhythms and many species' annual rhythms of reproduction, hibernation, and so forth.

slow-wave sleep

These stages differ in the number of long, slow waves. Stage 2 has the fewest and stage 4 has the most. These waves indicate synchrony among neurons, related to decreased brain activity. The waves grow larger because the little brain activity that does occur drives many neurons in synchrony.

sleep walking

When you awaken, various brain areas don't necessarily all awaken at once. Occasionally, most of your cortex awakens but one part of your medulla continues sending inhibitory messages to the spinal cord, just as it does during REM sleep. You then find yourself alert, with your eyes open, but temporarily unable to move your arms or legs. Sleepwalking tends to run (walk?) in families, mostly in children and mainly during stage 4 sleep. Some adults sleepwalk also, mostly during the first half of the night's sleep, and not while dreaming. They have clumsy, apparently purposeless movements with only limited responsiveness to their surroundings. Contrary to what you may have heard, wakening a sleepwalker is not dangerous, although it is not particularly helpful either . A better idea is to guide the person gently back to bed. In addition to walking during sleep, some people have been known to eat, rearrange furniture, drive cars, and engage in sex (either by masturbation or with a partner) during sleep. You might wonder, is the person really asleep? The answer is "sort of." As mentioned, the entire brain doesn't necessarily wake up or go to sleep all at once. Sleep can be localized to one brain area more than another. Sleepwalking occurs when the motor cortex and a few other areas are active while most of the brain remains asleep

suprachiasmatic nucleus

a cluster of neurons in the hypothalamus in the brain that governs the timing of circadian rhythms. The circadian rhythm of sleep and wakefulness is generated within the brain by a tiny structure known as the suprachiasmatic nucleus (SCN). If it is damaged, the body's activity cycles become erratic.

deja vu experience

a feeling that an event is uncannily familiar, is fairly common in young adults and less so as people grow older.

circadian rhythm

a rhythm of activity and inactivity lasting about a day. (The term circadian comes from the Latin roots circa and dies, meaning "about a day.")

Meditation

a systematic procedure for inducing a calm, relaxed state through the use of special techniques, follows traditions that have been practiced in much of the world for thousands of years, especially in India. One variety of meditation seeks "mindfulness" or thoughtless awareness, in which the person is aware of the sensations of the moment but otherwise passive

Evolutionary Theory of sleeping

also known as the adaptive theory of sleep, suggests that periods of activity and inactivity evolved as a means of conserving energy. According to this theory, all species have adapted to sleep during periods of time when wakefulness would be the most hazardous

Consiousness

as the subjective experience of perceiving oneself and one's surroundings. However, that definition relies on the phrase "subjective experience," which is no better defined than consciousness itself. Researchers use this operational definition: If a cooperative person reports being conscious (aware) of one stimulus and not of another, then he or she was conscious of the first and not the second.

coma

caused by traumatic brain damage, the brain shows a steady but low level of activity and no response to any stimulus, including potentially painful stimuli.

night terrors

causes someone to awaken screaming and sweating with a racing heart rate, sometimes flailing with the arms and pounding the walls

activation-synthesis theory

dreams occur because the cortex takes the haphazard activity that occurs during REM sleep plus whatever stimuli strike the sense organs and does its best to make sense of this activity

minimal conscious state

in which people have brief periods of purposeful actions and speech comprehension

Hypnosis

is a condition of focused attention and increased suggestibility that occurs in the context of a special hypnotist-subject relationship

Narcolepsy

lose the brain cells that produce orexin, and therefore return to a pattern resembling infants.They experience sudden attacks of sleepiness during the day.

Energy Conservation Theory

sleep is an adaptation that allows us to conserve energy for gathering food, defeating predators

Electroencepholograph eeg

sleep researchers distinguish among sleep stages by recording brain waves with electrodes attached to the scalp.measures and amplifies tiny electrical changes on the scalp that reflect patterns of brain activity

Stages 3 and 4 of sleep

slow wave or deep sleep with delta waves below 3.5 hz

Repair Sleep Theory

that sleep allows for the body to repair and replete cellular components necessary for biological functions that become depleted throughout an awake day.

activation-synthesis theory

the activation synthesis theory makes no clear, testable predictions. For example, the muscles are always paralyzed during REM sleep. Why don't we always dream that we cannot move? Perhaps a more serious problem for this theory is that dream experiences, although strange, do not appear to be random or haphazard. theory that dreams reflect inputs from brain activation originating in the pons, which the forebrain then attempts to weave into a story.

brain death

the brain shows no activity and no response to any stimulus

energy conservation

the practice of finding ways to use less energy or to use energy more efficiently

Restoration Sleep Theory

theory that sleep is a biological need

Freud theory of dreams

unconscious thoughts and desires that need to be interpreted, little scientific support manifest content—the content that appears on the surface— and a latent content—the hidden ideas that the dream experience represents symbolically.