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Consciousness and states of awareness

Consciousness and states of awareness. Consciousness – what we are aware of at any given time Sensation/perception – how we sense thing both internal and external world Consciousness – What we sense/perceive Factors affecting consciousness (awareness) Attention

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Consciousness and states of awareness

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  1. Consciousness and states of awareness • Consciousness – what we are aware of at any given time • Sensation/perception – how we sense thing both internal and external world • Consciousness – What we sense/perceive • Factors affecting consciousness (awareness) • Attention • Altered states (drugs, hypnosis, meditation, etc.) • Continuum of wakefulness

  2. Controlling attention • Attentional control – Can we always ignore or attend to just what we want? Big Small Couch Chair Him Her Green orange blue yellow purple White Stroop effect

  3. Stroop effect • Distinction between automatic and controlled processing • Reading – automatic • Color naming –controlled

  4. Consciousness or states of arousal • Affects attention and other behaviors • Some different states of arousal/consciousness • Sleep • Drugs • Hypnosis • Meditation • Form a continuum

  5. Circadian rythms • 24-hour body clock • Many functions exhibit circadian rhythms • Alertness • Body temperature • Hormone release

  6. Circadian rhythms and levels of alertness • Most aware of this one • Generally gradual increase until about noon • Dip after noon • Slow decline until night fall • All nighters and circadian rhthms • 3-5 am most difficult time • Surge around 10 am • Won’t necessarily fall asleep earlier

  7. What controls circadian rhythms • Is it light dark cycle? • Why this would be reasonable • Cave experiment

  8. Sleep • Under control of circadian rhythms • Importance of the electroencephalograph (EEG) • How does it work • Initial theories about sleep • Unitary state theory

  9. Sleep research EEG and sleep

  10. Stages of sleep

  11. Rapid eye movement (REM) sleep • Brain activity closest to waking state • Muscles are most relaxed • Least likely stage to sleepwalk (stages 1 and 2 most likely • Most difficult stage to wake someone from • If awakened about 90% will report dreaming • If awaken during stage 4 about 10% report dreaming • So important other stages called Non-REM sleep

  12. Stages of sleep through the night • First fall asleep – Stage 1 (hynogogic) only when first fall asleep • stage 4 after about 30 minutes • Most responsive to external stimuli here • Cycle back to stage 2 then have first REM bout • First REM relatively short

  13. Stages of sleep through the night • Usually 4-5 cycles per night • Easiest to wake at earlier stages • Will be most alert wake at earlier stages • Least alert wake at REM or stage 4 • Implications for staying awake all night

  14. Stages of sleep through the night • Changes throughout night • Duration of REM periods increase • Time in stage 4 decreases

  15. How much sleep do we need • Variable • Most (70%) need 7-8 hours • Small percent need lot less or lot more • Extraordinary cases need less than 1 hr

  16. Species comparisons

  17. Changes across the life span • Infant can need up to 16 hours • By 60-70 generally around 6 hours • College students 7-8

  18. Why do we sleep • Is it restorative • Evidence against • Is it to dream (Freud) • What areas of brain most active during sleep • Evolutionary explanation of why we sleep

  19. Neural basis of dreaming • Which areas of brain most active during dreaming • Physiological approach to dream interpretation? Areas active during dreaming

  20. Effects of sleep deprivation • World record for hours without sleep 264 hours (11 days) • Impossible to go without sleep indefinitely • Importance of REM sleep • REM rebound • Effects of REM and non-REM deprivation on task performance

  21. REM vs. Non-REM deprivation

  22. Sleep disorders • Insomnia (different types) • Difficulty falling asleep • Difficulty falling back to sleep (if awakened) • Light sleep (easily awakened) and fail to get sufficient REM • Sleep apnea • Difficulty (cessation) of breathing during sleep • Can awaken 500 times during night • Failure to get sufficient REM

  23. Sleep apnea treatment

  24. Sleep disorders • Narcolepsy • Sudden onset of sleep • Go immediately into REM • Often report hallucinations (probably just dreams)

  25. Neural basis of sleep

  26. Psychoactive drugs • Changes in consciousness that can affect behavior • Range from stimulants to depressants • Most common (in order) • Caffeine • Nicotine • Alcohol • Tranquilizers • Illegal drugs

  27. Depressants • Alcohol – by far most common • Physiological effects general slowing of NS • Low doses produce general sense of well being • Blood alcohol levels (.05) • Higher doses (BAL .1) • More aggressive • Severe cognitive impairment • Severe physical impairment • Extremely high does (BAL > .7) can result in death

  28. Brain images of alcohol Lighter areas indicate higher activity

  29. Depressants continued • Barbiturates • Range from mild (valium) to strong (anesthetics) • Can produce physical addiction • Withdrawal produces physical symptoms • Biggest danger: combined with alcohol can cause death • Essentially giving two depressants • Opiates • Strongest narcotics • Physical addiction • Withdrawal can cause death

  30. Stimulants • Examples: Nicotine, caffeine, cocaine • Produce general increase in both somatic and autonomic nervous system • BP, heart rate, digestion, all increase • Jitters and other physical manifestations • Mild stimulants (nicotine, caffeine) can have beneficial effects on performance • Improved concentration, awareness, better performance

  31. Stimulants (cont’d) • Many stimulants can be physically addicting • Nicotine, caffeine, cocaine • Most act as appetite suppressors. • Most act by increasing action of dopamine • Prevent breakdown • Increase release • Release of dopamine and pleasure centers

  32. Hallucinogens • Examples: Marijuana, LSD, phencyclidine (PCP- “angel dust”) • Distort perceptions • Mild distortions (e.g., marijuana): general slowing of time, increased attention to sensory input • Severe distortions (e.g., LSD): Multi-sensory distortions – (e.g., sound produces visual, tactile experience)

  33. Hallucinogens (cont’d) • PCP –phencyclidine • Used as anesthetic • Produces serve hallucinations and delusions • Combination is particularly dangerous

  34. Hypnosis • Definition • State of arousal between sleep and wake • Heightened suggestibility • Can respond to external stimuli • Large individual differences • About 15% of people highly hypnotizable • About 10% not responsive at all • Post hypnotic suggestions • What are they? • Do people remember • Limitations

  35. Hypnosis example

  36. Hypnosis • Does it work? • Pain relief • Possible mechanism: Experience not available to consciousness • Dissociation explanation – temperature experiment (one hand in ice water; other hand asked to write by free association) • Dissociation between behavior and what is written • Recall of memories • Use in eyewitness testimony • Repressed memories of sexual abuse?

  37. Meditation • Is it a “different” state • Physiological changes • Are they different from other points along the continuum of arousal

  38. Selective attention • Definition • Effects • On attended stimuli • On unattended stimuli • Testing • Dichotic listening task • Performance on attended ear • Performance unattended ear • Physical changes in unattended ear

  39. Selective attention • Humans have superb selective attention abilities • Cocktail party phenomenon • Can attend to one conversation among many • Sometimes want non-attended stimuli become attended

  40. Two competing conversations

  41. Two competing conversations – different voices

  42. Importance of selective attention • Can attend to limited number of stimuli • Effects of requiring attention to too much stimuli • Dual task procedures • General procedures • Results

  43. Count the number of 1’s –single task 10 2 5 3 1 10 5 7 3 10 7 6 3 8 10 6 5 9 4 6 8 3 10 10 3 5 1 6 9 3 2 9 1 9 5 5 1 1 4 2 3 8 5 1 7 10 9 6 7 2 5 6 5 6 8 5 3 5 4 2 3 2 6 3 7 10 6 2 7 2 6 2 10 8 4 3 9 3 8 1 9 6 7 4 5 6 2 5 3 2 9 4 2 3 9 6 6 2 9 4 2 4 8 8 10 10 9 3 3 3 6 4 1 6 5 7 5 1 3 7 9 9 3 9 10 8 6 1 10 7 6 2 2 6 5 10 9 7 5 6 6 1 6 3 1 2 2 5 8 9 2 10 8 4 5 10 9 3 1 3 1 6 8 8 9 4 5 2 7 2 3 5 2 4 8 9 10 9 9 5 3 6 10 10 8 6 9 9 5 6 4 2 1 9 4 4 7 3 9 5

  44. Count the number of 1’s AND number of “the’s” 10 4 8 8 2 6 5 3 8 9 9 2 2 10 2 1 1 6 9 9 5 10 8 4 2 2 5 1 9 3 7 3 8 1 10 6 10 6 9 4 2 10 10 4 4 7 1 6 5 2 3 5 2 3 6 8 9 4 4 6 8 10 10 7 6 3 3 6 4 1 7 4 2 2 8 6 10 2 2 2 3 5 7 8 8 8 2 1 2 2 9 7 4 3 1 3 2 2 4 5 10 1 9 3 1 4 2 1 2 3 6 2 5 1 5 2 1 5 1 4 6 10 5 7 3 6 1 9 4 3 10 8 10 6 7 1 4 9 1 4 6 4 1 6 7 5 4 4 1 1 3 7 4 10 1 4 3 4 9 10 7 5 4 10 2 5 6 2 3 5 2 7 4 6 10 1 2 8 5 7

  45. Attention and dual tasks • Can attend to two or more stimuli simultaneously • Effects on performance • Everyday importance?

  46. Which do you like better 1 2 Great Rats

  47. Which do you like better 1 2 Great Rats

  48. Subliminal perception • Subliminal – below threshold • If has effect must be attended to • Not consciously aware of all we attend to • Subliminal messages outlawed • Recent controversy

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