Chapter 5: Variations in Consciousness

Consciousness: Personal Awareness

• Consciousness– Includes:

• Awareness of external events• Your awareness of internal sensations• Your awareness of the uniqueness of

having these experiences• Your awareness of the thoughts of these

experiences

Consciousness: Personal Awareness

• Levels of awareness• James 1902 – stream of consciousness- an

endless flow of ideas– Freud – unconscious- was one of the first

theorists to recognize that consciousness is not an all or none phenomenon…rather there are levels of awareness

• Sleep and dreaming researchers also showed that awareness is different during sleep and dreaming, but mental processes occur that are quite similar to waking thought and surprisingly sophisticated

The Electroencephalograph:A Physiological Index of Consciousness

• EEG – monitoring of brain electrical activity• Brain-waves: across large areas of the cerebral

cortex. It is basically a physiological index of consciousness

– Amplitude (height)– Frequency (cycles per second)

• Beta (13-24 cps): alertness and problem solving

• Alpha (8-12 cps) resting and relaxation• Theta (4-7 cps): low alertness and sleep• Delta (<4 cps): deep, dreamless sleep

Table 5.1 EEG Patterns Associated with States of Consciousness

p. 178

Biological Rhythms and Sleep

• Circadian Rhythms – 24 hr biological cycles– These daily cycles are particularly

important in the regulation of sleep, but also in the regulation of temperature, blood production, hormone production, and other bodily processes.

– Our bodies are set-up on a 24.2 hour sleep cycle

Fig. 5-3, p. 177


• Physiological pathway of the biological clock:– The pathway for regulation of the human biological

clock appears to be based in light levels, which go from the eye to an area of the brain called the suprachiasmatic nucleus (in the hypothalamus).

– This nucleus tells the pineal gland to secrete melatonin, a hormone that adjusts biological clocks

• Light levels retina suprachiasmatic nucleus of hypothalamus (in the hypothalamus) pineal gland secretion of melatonin


• Sleep and Work (or school for you)– Your body likes a set schedule– Shift rotation is hard on the body and leads

to more fatigue, lower production, and more accidents• 40% rise in cardio. Disease• Irregular menstrual cycles• increase in premature deaths• Lower fertility


• Melatonin and circadian rhythms– Melatonin supplements are sold in the U.S. as

nutritional supplements, but many researchers worry that people are taking too high doses of this substance, when long-term effects have not been tested.

– Research shows that may be helpful in the treatment of jet lag, but timing is very important and hard to get right. Studies also show that melatonin may be useful as a mild sedative, more so in the daytime than at night, when melatonin levels are naturally higher

Sleep/Waking Research

• Instruments:– Electroencephalograph – brain electrical

activity– Electromyograph – muscle activity – Electrooculograph – eye movements– may also record heart rate, breathing rate,

temperature, etc., as well as videotape the person sleeping through a window• people get used to the wires and

cameras after only one night

Sleep Stages: Cycling Through Sleep

• Stage 1: brief, transitional (1-7 minutes)– moves from predominately alpha waves,

when the person is just about to fall asleep, to more theta activity

– Hypnic jerks, those brief muscle contractions that occur when one is falling asleep, occur in stage 1 sleep.

• Stage 2: (10-25 minutes)– characterized by more mixed brain wave

activity with brief bursts of higher-frequency brain waves, called sleep spindles


• Stages 3 & 4: slow-wave sleep (30 minutes)– characterized by low frequency delta

waves; 30 minutes to reach stage 4, and usually people stay there for about 30 minutes

• Then the cycle reverses. When stage 1 should be next in line in the cycle, something interesting happens…rapid eye movement (REM) sleep begins. – REM sleep was accidentally discovered by

Nathaniel Kleitman in the spring of 1952


• Stage 5: REM– EEG that looks awake and alert…and by rapidly

moving eyes behind the lids, an irregular pulse and breathing rate, and loss of muscle tone

– someone awakened from REM sleep often reports vivid dreaming

– Developmental differences in REM sleep:• Infants spend much more time in REM than do

adults. • During adulthood, sleep changes continue with

the percentage of slow-wave sleep declining and the percentage of time spent in stage 1 increasing

Figure 5.5 An overview of the cycle of sleep

The Neural Bases of Sleep

• Brain Structures:– Ascending reticular activating system

• a system of afferent fibers running through the reticular formation that influence physiological arousal. When these fibers are cut, animals will sleep continuously. If they are stimulated, arousal and alertness result

– Pons (REM sleep), medulla, thalamus, hypothalamus, limbic system

The Neural Bases of Sleep

• Neurotransmitters:– Acetylcholine and serotonin (sleep itself)– Also norepinephrine, dopamine, and GABA

(involved in arousal and the course of sleep) • Basically, no one center or chemical is

at work; sleep is rather an interplay of many neural centers and neurotransmitters.

Figure 5.7 The ascending reticular activating system (ARAS)

Why Do We Sleep?

• Hypothesis 1:– Sleep evolved to conserve organisms’

energy• Hypothesis 2:

– Immobilization during sleep is adaptive because it reduces danger

• Hypothesis 3:– Sleep helps animals to restore energy and

other bodily resources

Sleep Deprivation

• Complete deprivation– Sleep deprivation studies indicate that

people can function surprisingly well when sleep deprived; although effects on mood and performance are present, these are modest

– 3 or 4 days max

Sleep Deprivation

• Partial deprivation or sleep restriction (very common)– impaired attention, reaction time, coordination, and

decision making – accidents: Chernobyl, Exxon Valdez

• Selective deprivation– When researchers wake subjects up whenever

they go into REM sleep, thus depriving them of this one particular stage, they find that soon, the person will try to go back into REM faster

– REM and slow-wave sleep: rebound effect

• College kids and standardized tests (both intelligence and moods)-– What were the results?

Featured Sleep Study

Figure 5.9 Effect of sleep deprivation on cognitive performance

Featured Study

• Those who were deprived of sleep did much worse, but predicted they did much better (and their attitudes/moods were still good)…

Sleep Problems

• Insomnia – trouble falling asleep, trouble remaining asleep, and persistent early morning awakening. – Difficulty falling asleep is most common

among young people, while early morning awakening and trouble staying asleep are more common among middle-aged and elderly people

– 34-35% of adults report problems with insomnia and about 15-17% have severe or frequent insomnia

– 50% more common in women than in men

Sleep Problems

• Narcolepsy – falling asleep uncontrollably during normal waking hours– person with Narcolepsy goes directly into

REM sleep• Sleep Apnea – reflexive gasping for air that

awakens– the person literally stops breathing for 15 to

60 seconds…can cause heart and lung damage

Sleep Problems

• Nightmares – anxiety arousing dreams - REM

• Night Terrors – intense arousal and panic - NREM

• Somnambulism – sleepwalking

Figure 5.12 Sleep problems and the cycle of sleep

Figure 5.11 The vicious cycle of dependence on sleeping pills

Dreams and Dreaming:Content and Significance

• Dreams – – mental experiences during REM sleep that

are often based in vivid imagery, have a storylike quality, are often bizarre, and seem real to the dreamer

– people dream in non-REM too, although the dreams are less story-like and vivid in imagery, recent research shows that content is usually not bizarre, and that dreamers are often aware that they are dreaming


– Content usually familiar– Common themes: include things like falling, being

pursued, trying repeatedly to do something, school, sex, being late, eating, being frightened, etc

• Children’s dreams appear to differ from those of adults, with preschool children reporting bland images with no story lines when awoken from REM sleep (if they recall dreaming at all – children under the age of 9-11 report dreaming only 20-30% of the time when awoken from REM sleep, as opposed to an adult’s 80% of the time).


• Between 5 and 8, children begin to report dream narratives, but these are not well developed. Adultlike dreams develop at around 11-13, suggesting that dreaming is a cognitive ability that develops gradually.

– Waking life spillover – day residue- Freud said that the contents of waking life tend to spill into dreams; he called this day residue

• Western vs. Non-Western interpretations

Figure 5.14 Three theories of dreaming

Hypnosis: Altered State of Consciousness or Role Playing?

• Hypnosis = a systematic procedure that increases suggestibility- as well as relaxation, narrowed attention, and enhanced fantasy.

• Hypnotic susceptibility: individual differences- 10% of people are especially easy to hypnotize, 10% especially difficult

• Susceptibility linked to higher levels of absorption in a task and in a person’s imaginativeness…greatly depends on expectations.

Hypnosis: Altered State of Consciousness or Role Playing?

• Effects produced through hypnosis:– Anesthesia– Sensory distortions and hallucinations– Disinhibition– Posthypnotic suggestions and amnesia

• Researchers argue about whether hypnosis is really an altered state of awareness or if it is simply people doing what they think they are supposed to do when they are hypnotized…the dissociation hypothesis holds that hypnosis splits consciousness into two streams…divided consciousness

Meditation

• Meditation = practices that train attention to heighten awareness and bring mental processes under greater voluntary control– Some of the most widely practiced forms of

meditation are yoga, Zen, and transcendental. All three of these are rooted in Eastern religions; however, many who meditate do so separately from religious practice

– Effects of meditation include decreased heart rate, respiration rate, etc., and a relaxed EEG, with predominant theta and alpha rhythm patterns

Meditation

• Yoga, Zen, transcendental meditation (TM)– Potential physiological benefits

• Similar to effective relaxation procedures• research using the CT scan to track

blood flow in the brain in experienced Tibetan Buddhist meditators shows high activity in the prefrontal cortex (an area important for focused attention) and low activity in parts of the parietal lobe that are known to process information about the body’s location in space

Psychoactive drugs

• Psychoactive drugs: modify mental, emotional, or behavioral functioning…

• Recreational drug use: pleasurable alterations in consciousness.

• Narcotics (opiates) – pain relieving; morphine, codeine, Demerol, and methadone…high doses produce an overwhelming sense of euphoria

• Sedatives – sleep inducing; barbiturates…downers• Stimulants – increase CNS activity; caffeine and

nicotine, as well as much stronger drugs such as cocaine and amphetamines

Psychoactive drugs

• Hallucinogens – distort sensory and perceptual experience; Hallucinogens such as LSD, mescaline, and psilocybin

• Cannabis – produce mild, relaxed euphoria; Cannabis is the hemp plant from which marijuana, hashish, and THC

• Alcohol – produces relaxed euphoria, decreases in inhibitions

• MDMA – produces a warm, friendly euphoria; ecstasy

Table 5.3 Psychoactive Drugs: Tolerance, Dependence, Potential for Fatal Overdose, and Health Risks

Drug Effects

• Tolerance: you need more of the drug to gain the same pleasure

• Physical Dependence: must take the drug to avoid withdrawal symptoms

• Psychological Dependence: must take the drug to satisfy mental and emotional cravings

• Many physiological and mental symptoms: vary based on the type of drug

Chapter 5: Variations in Consciousness

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