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Chapter 5- Consciousness

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1 Chapter 5- Consciousness
Consciousness: the awareness of internal and external stimuli You are aware of external events because of your senses EX- I can smell that yummy pie, I hear my mother yelling at me! You are aware of your internal sensations EX- I can feel my heart racing, I am starting to sweat You are aware of yourself and we are unique individuals separate from other people and our surroundings Ex- Why me? Little kids do not have a sense of self…this is why they may talk in the third person You are aware of your thoughts about experiences Ex- It is going to be cold if I jump in that pool right now. Consciousness never stops……it is always flowing…..stream of consciousness

2 States of Consciousness
Daydreaming Hypnosis Hallucinations Meditation Dreaming

3 Variations in Awareness
Sigmund Freud wanted to examine what goes on beneath the surface of consciousness. Freud argued that people’s feelings and behavior are influenced by unconscious needs, wishes and conflicts that lie below the surface of conscious awareness. Conscious and unconscious processes are different levels of awareness. Since Freud’s time, research has shown that people continue to maintain some awareness during sleep and sometimes even when under anesthesia for surgery. A new parent has been known to sleep through a loud thunderstorm but wake up at the quiet noise of their baby crying down the hall. The parents selective sensitivity to sound means that some mental processing must be going on even during sleep.

4 Consciousness and Brain Activity
Scientists are increasingly using brain imaging methods to explore the link between brain activity and consciousness. Electroencephalography (EEG)- device that monitors the electrical activity of the brain over time by means of recording electrodes attached to the surface of the scalp. This machine measures brain waves.

5 Correlation does not equal Causation
If you become drowsy while listening to me lecture, your brain wave activity will probably change. But are these changes causing your drowsiness, or is your drowsiness causing the changes in brain activity? There could also be a third variable.

6 Circadian Rhythms Are you a night person or a morning person?
Circadian rhythms are the 24 hour biological cycles found in humans and many other species. Regulates sleep, blood pressure, urine production, hormonal secretions, and other physical functions. Ex- Research indicates that people generally fall asleep as their body temperature begins to drop(night) and awaken as it begins to rise once again (morning).

7 Rule of Thumb: Recovery from Jet Lag
The Research To study biological clocks, researchers have monitored physiological processes while subjects are cut off from exposure to the cycle of day and night and all other external time cues. These studies have demonstrated that circadian rhythms generally persist even when external cues are eliminated. However, when people are isolated in this way, their cycles run a little longer than normal, about 24.2 hours on the average. When you ignore your biological clock and go to sleep at unusual times, the quality of your sleep typically suffers. Getting out of sync with your circadian rhythms is also the cause of jet lag. Rule of Thumb: Recovery from Jet Lag Takes about a day for each time zone crossed when flying eastward Takes about two-thirds of a day per time zone when you fly westward. Investigators do not know why circadian rhythms last longer when time cues are taken away but its not apparent under normal circumstances bc exposure to light readjusts people’s biological clocks.

8 The Sleep and Waking Cycle
Electromyograph (EMG)- records muscular activity Electrooculograph (EOG)- records eye movement Stages 1-4 (Non-REM) The length of time it takes for a person to fall asleep will vary but the average in a recent study of over 35,000 people from ten countries was 25 minutes. STAGE 1: Brief transitional stage of light sleep that usually lasts only minutes. Breathing and heart rate slow as muscle tension and body temperature decline. STAGES 2: Still a light stage of sleep but deeper than stage 1. Lasts about minutes. STAGES 3 AND 4(Slow wave sleep): Sleep is deep and the brain produces delta waves. Stage 4 is the deepest sleep meaning that it is the one during which someone would have the greatest difficulty waking up. Stage four is reached usually in less than an hour and continues for as much as a half-hour. NOW THE CYCLE REVERSES ITSLEF AND THE SLEEPER GRADUALLY MOVES BACK UPWARD THROUGH THE LIGHTER STAGES.

9 REM SLEEP When sleepers reach what should be stage 1 again, they usually go into the fifth stage of sleep. This is the stage most widely known as REM sleep (rapid eye movement). In humans, the REM stage tends to be a “deep” stage of sleep (hard to wake up) There is usually irregular breathing and pulse rate. Muscle tone is extremely relaxed…you are nearly paralyzed. Brain waves look that same as when you are awake on the EEG machine! MOST VIVID DREAMS HAPPEN HERE! During the course of the night people usually repeat the sleep cycle about four times. The cycle changes through out the night. The first REM cycle is short and later REM cycles get longer peaking at about minutes. NREM intervals tend to get shorter.

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11 Both the total amount of sleep per night and the portion of sleep that is REM change with age. Sleep patterns change the most dramatically during infancy.

12 Age Trends in Sleep Read pages 191-192 in text
Characteristic REM sleep NREM sleep Type of EEG Activity Mostly Beta. “Wide awake” brain waves Varied, lots of delta Eye Movements Rapid, lateral Slow or absent Dreaming Frequent and vivid Less Frequent Depth (Difficulty in awakening) Varied, generally difficult to awaken Varied, generally easier to awaken Percentage of total sleep (in adults) About 20%-25% About 75%-80% Increases or decreases (as percentage of sleep) during childhood) Percent decreases Percent increases Timing in sleep cycle (dominates early or late) Dominates late in cycle Dominates early in cycle

13 How important is REM sleep?
Selective deprivation- subjects are awaken consistently during REM sleep. RESULTS REM re-bound- You spend more time in REM sleep. Same thing happens when people are awakened during slow wave sleep. Research concludes that SWS and REM sleep must be important…why else would we spend so much time there after being deprived of it? Some studies found that REM and SWS sleep contributes to firming up learning that takes place during the day. Sleep also seems to enhance memory of specific learning activities that occurred during the day and that depriving subjects of either REM sleep or slow-wave sleep reduces these increments of memory

14 SLEEP DISORDERS INSOMNIA Most common sleeping disorder
People with insomnia have difficulty falling asleep(younger people) and staying asleep(older people) Associated with daytime fatigue, impaired cognitive functioning, elevated risks for accidents, reduced productivity, depression, anxiety, substance abuse, etc..

15 SLEEP APNEA Gasping for air that awakens a person and disrupts sleep. Some victims awake 100’s of times a night Stop breathing for a minimum of 10 seconds….loud snoring NIGHTMARES Anxiety rousing dreams that lead to awakening usually from REM sleep. Significant stress in one’s life is associated with increased frequency and intensity of nightmares NIGHT TERRORS Abrupt awakenings from NREM sleep accompanied by intense autonomic arousal and feelings of panic. Can cause an increase in heart rate….usually occur during stage 4 of sleep. Victims usually let out a cry and bolt upwards…and usually do not recall a dream but they may remember a frightening image. A return to sleep is usually easy SLEEPWALKING OR SOMNAMBULISM About 15% of children and 3% of adults exhibit repetitive sleepwalking. Usually occurs in the first 3 hours of sleep when you are in slow wave sleep Episodes may last for minutes. REM SLEEP BEHAVIOR DISORDER Acting out dreams….may yell, leap out of bed etc..you can hurt yourself or others

16 See chart on page 203 for most common dreams.
What do you dream about? See chart on page 203 for most common dreams. 42 percent of subject reported dreaming of water when they were sprayed with water during REM sleep……….I see an interesting experiment idea!

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19 HYPNOSIS A SYSTEMATIC PROCEDURE THAT TYPICALLY PRODUCES A HEIGHTENED STATE OF SUGGESTIBILITY. Not everyone can be hypnotized. About 10-15% of the population are good at being hypnotized. Although a number of theories have been developed to explain hypnosis, it’s still not well understood. One popular view is that hypnotic effects occur because participants are put into a special altered state of consciousness, called a hypnotic trance. Although hypnotized subjects may feel as thought they’re in an altered state, they do not seem to show reliable alterations in brain activity. Hypnosis & Surgery Pain Video from PowerLecture CD MEDITATION Trains attention to heightened awareness and brings mental processes under great voluntary control Important in many religions such as Buddhism

20 Brain Waves You are playing a video game Beta Waves – alert attention, wide awake You are deep in meditation Alpha Waves- relaxation You have just fallen asleep Theta Waves- stage 1 You are sleepwalking across the lawn Delta Waves stages 3 and 4 You are in the midst of a terrible nightmare Beta- REM sleep

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