3. Circadian Rhythms
• Many of our behaviors display rhythmic
variation.
– Circadian rhythms
• One cycle lasts about 24 hours (e.g. sleep-waking
cycle).
• Light is an external cue that can set the circadian
rhythm.
• Some circadian rhythms are endogenous suggesting
the existence of an internal (biological) clock.
4. Sleep
• Sleep is a behavior AND an altered state of
consciousness.
• We spend about a third of our lives in sleep.
– A basic issue is to understand the function of sleep.
5. Myths of Sleep
• Everyone needs 8 hrs of sleep per night to
maintain good health.
• No longer a myth
• In order to perform at optimal level
• Learning of complicated subjects such as calculus
can be done during sleep.
• Some people never dream.
• Dreams last only a few seconds.
• Genital arousal during sleep reflects dream
content.
• May be a useful index of physical versus psychological
causes of impotence in males
6. Stages of Sleep
• Hypnagogic state: “pre-sleep” stage marked by
visual, auditory and kinesthetic sensations.
• Non-REM
Stage one
Stage two
Stage three
Stage four
• REM: rapid eyes movements, high frequency brain
waves, paralysis of large muscles and dreaming
7. Functions of Sleep
• REM Sleep:
– Consolidation of new memories
– Role in learning
– Absent in lower mammals
• Non-REM sleep
– People deprived of all sleep show greater time
spent in non-REM sleep the next night.
8. Functions of Sleep
• New research shows that sleep helps
implant emotional memories and delete
unemotional memories.
9. Effects of Sleep Deprivation
• Reduced immunity
• Mood alteration
• Reduced concentration and motivation
• Increased irritability
• Lapses in attention
• Reduced motor skills
10. Theories of Sleep
• Repair/Restoration
– Sleep allows for recuperation from physical,
emotional, and intellectual fatigue.
• Evolutionary/Circadian
– Sleep evolved to conserve energy and protect
our ancestors from predators.
11. Theories of Dreaming
• Psychoanalytic: Dreams represent
disguised symbols of repressed desires and
anxieties.
– Manifest versus latent content
• Biological: Dreams represent random
activation of brain cells during sleep.
• Cognitive: Dreams help to sift and sort the
events of the day.
12. Dysomnias• Insomnia
– Difficulty in getting to sleep or remaining asleep and has
many causes.
– Situational: related to anxiety
– Drug-induced: Use of sleeping pills or other drugs can result
in insomnia
• Sleep apnea:
– Person stops breathing and is awakened when blood levels of
carbon dioxide stimulate breathing.
• Narcolepsy:
– Sleep appears at odd times.
– Sleep attack: urge to sleep during the day
13. Parasomnias
• Nightmares:
– Anxiety-arousing dreams
– Generally occurring during REM sleep.
• Night Terrors:
– Usually boys 4-12.
– Abrupt awakenings from NREM sleep
– Feelings of panic
14. Drugs
• Drugs
– Chemicals that have biological effects within the
body.
• Psychoactive drugs
– Chemicals that change conscious awareness or
perception.
– Depressants slow down the nervous system.
– Stimulants speed up the nervous system.
– Opiates relieve pain.
– Hallucinogens alter sensory perception .
15. Drug Use and Abuse
• Drug abuse:
– Drug use that causes emotional or physical harm to the
user.
• Addiction
– Results from repeated drug use.
• Tolerance
– More drug is required.
– Drug abstinence leads to withdrawal symptoms.
16. Drug Use and Abuse
• Drug dependence can be:
– Physical:
• Withdrawal reactions are noted when drug use is
terminated.
– Psychological:
• Associated with a craving for the drug
18. Depressants
• Alcohol is particularly dangerous when combined
with barbiturates.
– Abuse can lead to serious losses in cognitive
functioning
– In US involved in nearly ½ of all:
• Murders
• Suicides
• Spousal abuse
• Accidental deaths in the
– 3rd leading cause of birth defects
19. Stimulants
• Nicotine
– Considered single most preventable cause of
death & disease in US.
• Cocaine
– Causes physical damage
– Severe addiction
– Psychological dependence
– Can interfere with electrical activity of the heart
21. Hallucinogens
• LSD- associated with “bad trips”
• Marijuana has some properties of
depressants, narcotics and hallucinogens at
higher doses.
22. “Club Drugs”
• MDMA (Ecstasy)
– High doses can cause
• Dangerous increases in body temperature
• Dangerous increases in blood pressure
– Leading to
– Seizures
– Heart attacks
– Strokes
• Can produces long lasting damage to the brain.
23. Factors that Lead to Drug Abuse
• Positive associations: the drug is portrayed in a
positive fashion in the media.
• Biological factors: the drug induces a pleasurable
state (usually related to dopamine activity in the
brain).
• Prevention of withdrawal: person continues to
take the drug to avoid withdrawal effects.
• Conditioning of drug craving: cues associated
with drug use can elicit craving for the drug.
24. Hypnosis
• Hypnosis is an altered state of heightened
suggestibility.
• The hypnotic state is characterized by:
– Narrow and focused attention
– Imagination
– Passive receptive attitude
– Reduced reaction to pain
– Heightened suggestibility
25. Myths of Hypnosis
• People can be hypnotized against their will.
• People will do immoral things while
hypnotized.
• Hypnosis improves memory recall.
• Hypnotized persons have special strength.
• Hypnosis is fake.
26. Altered States
• Meditation
• refers to a set of techniques that promote a
heightened sense of awareness.
– can involve body movements and posture,
focusing of attention on a focal point, or control
of breathing
– can induce relaxation, lower blood pressure,
and can be associated with a sense of euphoria
27. Why do people alter
consciousness?
• Sacred rituals
• Social interactions
• Individual rewards
