1 / 49

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

una
Download Presentation

Consciousness and states of awareness

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  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

More Related