Chapter 5 & 6

1. Chapter 5 & 6 Sensation & Perception and States of Consciousness

2. Sensation • Sensation • our sensory receptors and nervous system receive and represent stimulus energy • Perception • organizing and interpreting sensory information, enabling us to recognize meaningful objects and events

3. Sensation

4. Sensation • Bottom-Up Processing • analysis that begins with the sense receptors and works up to the brain’s integration of sensory information • Top-Down Processing • information processing guided by higher-level mental processes

5. Sensation - Basic Principles • Psychophysics • study of the relationship between physical characteristics of stimuli and our psychological experience of them • Light- brightness • Sound- volume • Pressure- weight • Taste- sweetness

6. Sensation - Thresholds • Absolute Threshold • minimum stimulation needed to detect a particular stimulus 50% of the time • Difference Threshold • minimum difference between two stimuli required for detection 50% of the time • just noticeable difference (JND)

7. Perceptual Organization • Gestalt • tendency to integrate pieces of information into meaningful wholes

8. Perceptual Organization • Figure and Ground--organization of the visual field into objects (figures) that stand out from their surroundings (ground)

9. Perceptual Organization- Gestalt • Grouping • the perceptual tendency to organize stimuli into coherent groups • Grouping Principles • proximity--group nearby figures together • similarity--group figures that are similar • continuity--perceive continuous patterns • closure--fill in gaps • connectedness--spots, lines, and areas are seen as unit when connected

10. Perceptual Organization- Closure

11. Perceptual Organization- Grouping Principles • Gestalt grouping principles are at work here.

12. Perceptual Interpretation • Perceptual Adaptation • (vision) ability to adjust to an artificially displaced visual field • prism glasses • Perceptual Set • a mental predisposition to perceive one thing and not another

13. Perceptual Set- Schemas • What you see in the center is influenced by your perceptual set

14. Waking Consciousness • Consciousness • our awareness of ourselves and our environments • Selective Attention • focusing of conscious awareness on a particular stimulus

15. Sleep and Dreams • Circadian Rhythm • the biological clock • regular bodily rhythms, such as of wakefulness and body temperature, that occur on a 24-hour cycle

16. Sleep and Dreams • REM (Rapid Eye Movement) Sleep • recurring sleep stage • vivid dreams • “paradoxical sleep” • muscles are generally relaxed, but other body systems are active • Sleep • periodic, natural, reversible loss of consciousness

17. Sleep Deprivation • Effects of Sleep Loss • fatigue • impaired concentration • depressed immune system • greater vulnerability to accidents

18. Sleep Disorders • Insomnia • persistent problems in falling or staying asleep • Narcolepsy • uncontrollable sleep attacks • Sleep Apnea • temporary cessation of breathing during sleep • momentary reawakenings

19. Night Terrors and Nightmares • Night Terrors • occur within 2 or 3 hours of falling asleep, usually during Stage 4 • high arousal - appearance of being terrified • seldom remembered

20. Dreams: Freud • Sigmund Freud--The Interpretation of Dreams (1900) • wish fulfillment • discharge otherwise unacceptable feelings • Manifest Content • remembered story line • Latent Content • underlying meaning

21. Dreams: Freud • Dreams • sequence of images, emotions, and thoughts passing through a sleeping person’s mind • hallucinatory imagery • discontinuities • incongruities • delusional acceptance of the content • difficulties remembering

22. Dreams • As Information Processing • helps facilitate memories • As a Physiological Function • periodic brain stimulation • REM Rebound • REM sleep increases following REM sleep deprivation

23. Hypnosis • Hypnosis • a social interaction in which one person (the hypnotist) suggests to another (the subject) that certain perceptions, feelings, thoughts, or behaviors will spontaneously occur

24. Drugs and Consciousness • Psychoactive Drug • a chemical substance that alters perceptions and mood • Physical Dependence • physiological need for a drug • marked by unpleasant withdrawal symptoms • Psychological Dependence • a psychological need to use a drug • for example, to relieve negative emotions

25. Psychoactive Drugs • Depressants • drugs that reduce neural activity • alcohol, barbiturates, opiates • slow body functions

26. Psychoactive Drugs • Alcohol • affects motor skills, judgment, and memory • reduces self awareness • Barbiturates • drugs that depress the activity of the central nervous system, reducing anxiety but impairing memory and judgment

27. Psychoactive Drugs • Opiates • opium and its derivatives (morphine and heroin) • opiates depress neural activity, temporarily lessening pain and anxiety • highly addictive

28. Psychoactive Drugs • Stimulants • drugs that excite neural activity • caffeine, nicotine, amphetamines, cocaine • speed up body functions

29. Psychoactive Drugs • Amphetamines • drugs that stimulate neural activity, causing speeded-up body functions and associated energy and mood changes

30. Psychoactive Drugs • Cocaine • effects depend on dosage, form, expectations, personality and situation • coca leaves • powder • crack

31. Cocaine Euphoria and Crash

32. Psychoactive Drugs • Ecstasy • MDMA (methylenedioxymethamphetamine) • stimulant and mild hallucinogen • dangerous short and long term effects

33. Psychoactive Drugs • Hallucinogens • psychedelic (mind-manifesting) drugs that distort perceptions and evoke sensory images in the absence of sensory input • LSD • MDMA (Ecstasy)

34. Psychoactive Drugs • LSD • lysergic acid diethylamide • a powerful hallucinogenic drug • also known as acid • THC • the major active ingredient in marijuana • triggers a variety of effects, including mild hallucinations

35. Psychoactive Drugs