Chapter 4 States of Consciousness

1. Chapter 4States of Consciousness

2. What is Consciousness? Consciousness is everything we are aware at any given time-our thoughts, feelings, sensations and external environment

3. Altered States of Consciousness Altered state of consciousness A change in awareness produced by sleep, meditation, hypnosis, or drugs

4. Circadian Rhythms Regular fluctuation from high to low points of certain bodily functions and behaviors within a 24-hour cycle Regulate all vital life functions

5. Influence of Circadian Rhythms Suprachiasmatic nucleus Structure in hypothalamus Body�s biological clock Controls timing of circadian rhythms Signals pineal gland to secrete or suppress melatonin

6. Disruptions in Circadian Rhythms Subjective night time during a 24-hour period when biological clock tells a person to go to sleep Jet lag and working during subjective night disrupt circadian rhythms Can lead to sleep difficulty and reduced alertness

7. Sleep Deprivation Effects: Difficulty concentrating Impaired learning Negative mood Effects on brain Decreased activity in temporal lobes during verbal learning tasks Increased activity in prefrontal cortex and parietal lobes To compensate for decreased temporal lobe activity

8. Why Do We Sleep? Circadian theory of sleep Sleep evolved to keep humans out of harm�s way during night Also known as evolutionary theory Restorative theory of sleep function of sleep is to restore body and mind Day-light savings time study

9. How do we study sleep? EEG � measures brain waves EOG � measures eye movements EMG � measures muscle activity Beta waves Alpha waves Theta waves Sleep spindles Delta waves REM sleep

10. Sleep Cycles During a typical night�s sleep, a person goes through about five 90-minute cycles

11. Sleep Cycles cont� Stage 1 (NREM) Transition stage between waking and sleeping Irregular EEG waves; some alpha waves, theta waves Stage 2 (NREM) Deeper sleep than in stage 1 Sleep spindles appear in EEG Stage 3 (NREM) Beginning of slow-wave sleep EEG registers 20% delta waves Stage 4 (NREM) Deepest stage of NREM sleep More than 50% delta waves Growth hormones are secreted

12. Types of Sleep NREM and REM NREM sleep Non-rapid eye movement sleep Characterized by slow respiration and heart rate, little body movement, and low blood pressure and brain activity REM sleep Characterized by rapid eye movements, paralysis of large muscles (atonia), fast and irregular heart and respiration rates, increased brain activity, and vivid dreams REM without atonia REM sleep may be critical to consolidation of new memories

13. Sleep Cycles (90 minutes) 1 2 3 4 3 2 REM REM 2 3 4 3 2 2 3 2 REM REM 2 REM 2

14. Figure 4.1 Brain-Wave Patterns Associated with Different Stages of Sleep

15. Content of Our Dreams REM dreams Have a story-like quality More visual, vivid, and emotional than NREM dreams NREM dreams Occur during NREM sleep Less frequent and memorable than REM dreams

16. Interpreting Dreams�Freud � royal road to unconscious.� Dreams satisfy unconscious sexual and aggressive desires. These wishes are unacceptable to dreamer and must be disguised in symbolic forms Manifest content content of a dream as recalled by dreamer Latent content underlying meaning of a dream

17. Interpreting Dreams cont� Activation-synthesis theory of dreaming Dreams are brain�s attempt to make sense of random firing of neurons during REM sleep Evolutionary theory of dreaming Vivid REM dreams enable people to rehearse skills needed to deal with threatening events

18. Figure 4.2 Average Hours of Daily Sleep across Life Span

19. Sleep Disorders Parasomnias: a sleep disturbance in which behaviors and physiological states that normally occur only in waking state take place during sleep Exclusively occur in Stage 4 (except sleep talking) Sleepwalking Sleeptalking Sleep driving Sleep eating Sleep terrors

20. Sleep Disorders cont� Dyssomnia: timing, quantity, or quality of sleep is impaired Sleep apnea Insomnia Narcolepsy Cataplexy

21. Psychoactive Drugs Any substance that alters mood, perception, or thought Controlled substances: approved for medical use Illicit substances are illegal

22. How Drugs Affect the Brain Create a sense of pleasure by increasing availability of dopamine in nucleus accumbens How drugs affect neurotransmission Opiates mimic effects of endorphins Depressants act on GABA receptors Stimulants mimic effects of epinephrine

23. Substance Abuse and Addiction Substance abuse Continued use of a substance after several episodes in which use has negatively affected an individual's work, education, and social relationships Physical drug dependence Compulsive pattern of drug use in which user develops drug tolerance coupled with unpleasant withdrawal symptoms when drug use is discontinued Psychological drug dependence A craving or irresistible urge for drug�s pleasurable effects

24. Stimulants Speed up activity in central nervous system Suppress appetite Make people feel more awake, alert, and energetic Stimulants include Caffeine Nicotine Amphetamines Cocaine

25. Depressants Decrease activity in central nervous system Slow down bodily functions Reduce sensitivity to outside stimulation Sedative-hypnotics Alcohol Barbiturates Minor tranquilizers (benzodiazepines) Narcotics (opiates) Morphine, heroin Oxycontin, Vicodin

26. Hallucinogens Drugs that can alter and distort perceptions of time and space, alter mood, cause hallucinations Also called psychedelics Hallucinogens include Marijuana LSD Designer drugs (e.g., MDMA or Ecstasy)