Criteria of Consciousness

Transcription

1 SLEEP AND DREAMS

2 Criteria of Consciousness self he or she must be able to recognize himself as distinguished from the environment. time he or she must be able to discriminate between the presentation in the physical world. location in space he or she must have a sense of his or her location in the present world.

3 Sleep: state of consciousness in which the body engages in some housekeeping tasks such as digestion and waste product removal Definition

4 Circadian Rhythms biological clock or person s daily sleep and wakefulness cycle controlled by superchiasmatic nucleus of the hypothalamus influenced by external cues such as light and dark wakefulness: (high point, increased body temperature and cortisol levels w/ vision, hearing, smell, taste, and peak alertness); (low point, decreased body temp. and cortisol levels and increased sleepiness) 25-hour cycle; free running when no cues interfere jet lag: discrepancy between biological clock and official clock (fitful sleep and sluggishness)

5 Sleep Patterns decrease w/ age: infant (16 hrs.), average adult (7-8 hrs.), average person 70 or over (6 hrs) Sleep Patterns

6 EEG patterns measure brain waves. As we move from an awake state through deeper stages of sleep, our brain waves decrease in frequency (cycles per second) and increase in amplitude (height). EEG beta patterns are associated with being awake. Stages of Sleep

7 Model Alpha Waves drowsy but awake state when eyes are closed and relaxed. Stage 1 Sleep transition between wakefulness and real sleep. Theta waves. EEG pattern changes to small, irregular pattern. After 5-10 minutes, move on to Stage 2. Wake up in this stage of sleep. Stage 2 Sleep Sleep spindles occur. Muscles less tense, eyes rest. EEG irregular. After 15 minutes, go on to Stage 3. Half of our sleep time is in Stage 2. Stage 3 Sleep EEG delta waves appear about percent of time. Slow-wave sleep. Stage 4 Sleep Over half the waves are delta. Most difficult to awaken from; deepest sleep. Decrease with age. We spend the first 30 to 45 minutes going from Stage 1 to Stage 4 sleep. The next 30 to 45 minutes is spent reversing in direction, from Stage 4 back to Stage 1. At this point, REM sleep occurs.

8 REM rapid eye movement; paradoxical sleep; deep sleep. EEG patterns resemble those of someone who is awake. Heart rate, respiration, blood pressure, and other physiological patterns are like those occurring during the day. atonia: loss of muscle tone or paralysis Most of our dreaming occurs. Incorporate environmental stimuli.

9 NREM: orthodox sleep; few dreams occur; sleeptalking and sleepwalking occur. NREM

10 During the night, we travel back and forth through the stages four to six times. Each completed cycle takes about 90 minutes. First half of night: deeper sleep. Last half: dominated by Stage 2 and REM sleep, from which we wake up. Sleep Cycles

11 Theories of Sleep adaptive theory: Each species needs a certain amount of time awake in order to survive. Sleep is an adaptive mechanism that protects members of a species by keeping them out of trouble during time not devoted to survival activities. conserving energy theory: Sleep is a protective method for conserving energy because we burn fewer calories while sleeping. restorative function theory: Sleep is necessary for resting and restoring the body, for nervous system development, and for consolidating what has been learned during the day.

12 Dreaming is a mental experience that occurs during sleep and consists of vivid images. While we dream we accept bizarre happenings without question. Lucid dreaming occurs when a sleeper is aware of dreaming while a dream is happening. Dreaming

13 Dream Theory Psychoanalytic Theory: Dreams are repressed desires and provide access to the unconscious in symbolic form. Sexual and aggressive impulses are disguised in our dreams. Activation-Synthesis Model: Dreaming is the brain s attempt to make sense out of random electrical activity that enters the forebrain during REM sleep. Dreams are a response to this random electrical activity and have no meaning. Housekeeping Hypothesis: The cleaning up or clearing out of unneeded neural connections occurs during dreaming, which is why the brain creates random electrical activity. Off-line Hypothesis: REM sleep plays a role in learning by integrating new and old information.