1. Chapter 4:Consciousness
Consciousness can be divided into two groups:
waking consciousness, in which an individual is alert and aware of his or her surroundings
altered states of consciousness, which represent any measure of arousal different from the normal waking state (e.g., sleeping, drug use, meditation)
Even in waking consciousness, awareness is not uniform
Selective attention is a conscious focus on one stimulus or perception at a given time
Selective inattention refers to the environmental stimuli screened out or ignored while your attention is selectively focused on something else
The consequences of multitasking, or divided attention, can be negative and even deadly

2. Our Biological Clock
The circadian rhythm is our biological clock, which regulates various bodily functions on approximately a 24-hour cycle
Thinking and memory peak with circadian arousal and this peak occurs at different times for different people
The suprachiasmatic nucleus causes the pineal gland to either increase (in the evening) or decrease (in the morning) the production of melatonin, a sleep-inducing hormone
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3. Why We Need Sleep
LO 4.4 Describe the function of sleep and consequences of sleep depravation.
Theories for why we sleep include preservation and protection, body restoration, learning, memory, synaptic plasticity, and growth
Sleep deprived students can experience difficulty studying, irritability, fatigue, a lowered rate of productivity, and a tendency to make mistakes
Sleep deprivation can have dire consequences for our physical and mental health
There is a consistent relationship between lack of adequate sleep and obesity
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4. Figure 4.1 Sleep Duration Recommendations
The recommended hours of sleep each night decreases with age. Even within each age group, a range of appropriate hours of sleep exists. It is important to find the number of hours of sleep that is right for your age, body, and lifestyle.

5. Stages of Sleep
High frequency and irregular beta waves characterize active wakefulness; slower alpha waves characterize a relaxed or drowsy state
Theta waves are brain waves associated with the transition to sleep (stages N1 and N2 – Non-REM)
Stage N3 consists of higher amplitude delta waves; we then enter stage R, which refers to rapid eye movement (REM) sleep
Periods of REM sleep increase in both duration and frequency the longer we sleep
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6. Stages of Sleep (1 of 4) LO 5.1b Identify the different stages of sleep and the neural activity and dreaming behaviors that occur in each.
We cycle through five stages of sleep in 90-minute cycles.
Stages 1–4 (Non-REM)
No rapid eye movements, fewer dreams
Stage 5 (REM) sleep
Vivid dreams
Rapid eye movements (REM)

7. Stages of Sleep (2 of 4) LO 5.1b Identify the different stages of sleep and the neural activity and dreaming behaviors that occur in each.
Stage 1 (5–10 minutes/cycle)
Theta waves
Hypnagogic imagery
Myoclonic jerks
Stage 2 (10–30 minutes/cycle)
Sleep spindles and K-complexes
As much as 65 percent of total sleep

8. Stages of Sleep (3 of 4) LO 5.1b Identify the different stages of sleep and the neural activity and dreaming behaviors that occur in each.
REM sleep
Called paradoxical sleep as bodies are paralyzed but brains are active
REM rebound occurs when we don’t rest well for several nights.
Function of the eye movements is unknown.
Muscles in middle ear are also active.
Stages 3 and 4 (15–30 minutes/cycle)
Delta waves
Crucial to feel rested; suppressed by alcohol
40 percent of sleep in children; 25 percent in adults
Stage 5 (REM sleep; 10–20 minutes/cycle)
Brain activity similar to wakefulness
Becomes longer as the night goes on

9. Figure 5.2 Stages of Sleep in a Typical Night
Source: Dement, 1974

10. Sleep Disorders
LO 4.6 Distinguish the various sleep disorders and their treatments.
Insomnia is characterized by dissatisfaction with the duration or quality of sleep
Narcolepsy is characterized by excessive daytime sleepiness and periodic, uncontrollable sleep attacks
Sleep apnea is a sleep disorder involving regular interruptions of breathing during sleep
Nightmares, sleep terrors, and sleepwalking are parasomnias, which refer to abnormal behavioral, experiential, or physiological events that occur in conjunction with sleep
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11. Dreams
LO 4.7 Recognize the different theories proposed to explain the function of dreams.
Freud classified dreams into: the manifest content (actual details) and the latent content (the unconscious)
The activation-synthesis hypothesis states that dreams are the result of the brain’s attempt to make sense of random neural activity originating in sub-cortex (figure right)
The information-processing perspective suggests that dreams may help us sort and place the day’s experiences into our memories

12. Figure 4.5 Psychotropic substances: Drugs that alter consciousness Classes of Drugs
There is some variation in the way to classify psychoactive drugs, but a common method includes the classes of depressants, stimulants, narcotics, and hallucinogens.

13. Depressants and Stimulants
LO 4.9 Differentiate depressant and stimulant psychoactive drugs and their effect on the body.
Depressants are drugs that depress or slow down the central nervous system and other bodily functions
e.g., alcohol, barbiturates, and benzodiazepines
Stimulants excite or increase the functioning of the central nervous system and speed up the body
e.g., caffeine, nicotine, amphetamines, and cocaine
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14. Narcotics and Hallucinogens
LO 4.10 Describe the effects of narcotic and hallucinogenic psychoactive drugs.
Narcotics are a type of depressant used medically in the management of pain and can produce feelings of euphoria
e.g., codeine, morphine, hydrocodone, oxycodone, and heroin
Hallucinogens are a class of drugs that can produce unusual sensations, distortions in the perception of reality, and intense emotional mood swings
e.g., magic mushrooms, LSD, and marijuana

15. Mapped connections for drug-free brain (left) and brain on Psilocybin “Magic” Mushrooms

16. Substance Use Disorders
LO 4.8 Recognize the symptoms associated with a substance use disorder.
Physiological dependence is where the body becomes physically dependent on the drug
Psychological dependence refers to emotional or motivational symptoms that include intense cravings for the drug, inability to concentrate, and/or feeling restless
Tolerance involves the body becoming used to the drug and needing more of it to achieve the same effect
A substance use disorder is diagnosed when a pattern of drug use leads to significant impairment or distress in the person’s life

17. Figure 4.8 Marijuana’s Effect on the Developing Brain

18. How Psychoactive Drugs Work Agonists vs. Antagonists
©John Wiley & Sons, Inc Huffman: Psychology in Action (8e)

19. Meditative techniques
Method of altering consciousness often associated with positive health benefits
Two general types: Concentrative (focused attention) and ‘open’ (mindful)
©John Wiley & Sons, Inc Huffman: Psychology in Action (8e)

20. Upper Paleolithic Cave Art: Indications of rituals to achieve ASC?
©John Wiley & Sons, Inc Huffman: Psychology in Action (8e)

21. Traditional ceremonies
Mandan Indiana sun-dance: altered state as pain endurance
©John Wiley & Sons, Inc Huffman: Psychology in Action (8e)