Chapter 4 psychology

• Consciousness


  Our awareness of internal and external stimuli
• Consciousness


  • Awareness of internal stimuli (e.g. pain, hunger, thirst, sleepiness, thoughts, emotions)
  • Awareness of external stimuli (e.g. seeing light, feeling warmth, hearing voice)
• Sleep


  A state marked by relatively low levels of physical activity and reduced sensory awareness, distinct from periods of rest during wakefulness
• Wakefulness


  Characterized by high levels of sensory awareness, thought, and behavior
• Other states of consciousness

  • Daydreaming
  • Intoxication
  • Unconsciousness due to anesthesia
• Biological rhythms


  Internal rhythms of biological activity
• Circadian rhythm


  A biological rhythm that takes place over a period of about 24 hours
• Circadian rhythms


  • Sleep-wake cycle linked to light-dark cycle
  • Daily fluctuations in heart rate, blood pressure, blood sugar, body temperature
• Suprachiasmatic nucleus (SCN)


  The brain's clock mechanism located in the hypothalamus
• Light information received through projections from the retina


  Allows the SCN to synchronize the internal clock with the outside world
• Melatonin


  A hormone released by the pineal gland that regulates various biological rhythms and the immune system during sleep
• Chronotype


  Individual differences in circadian patterns of activity (e.g. morning larks, night owls)
• Sleep regulation


  The brain's control of switching between sleep and wakefulness and coordinating this cycle with the outside world
• Jet lag


  A collection of symptoms resulting from the mismatch between internal circadian cycles and the environment when traveling across multiple time zones
• Rotating shift work


  A work schedule that changes from early to late on a daily or weekly basis, disrupting normal circadian rhythms
• Insomnia is a consistent difficulty in falling or staying asleep for at least three nights a week over a month's time
• Jet lag


  A collection of symptoms that results from the mismatch between our internal circadian cycles and our environment, including fatigue, sluggishness, irritability, and insomnia
• Rotating shift work


  A work schedule that changes from early to late on a daily or weekly basis, which disrupts circadian rhythms and can lead to sleeping problems, depression, and anxiety
• Rotating shift work


  Affects relationships with family
• Bright light exposure


  • Can help combat insomnia and symptoms of anxiety and depression caused by disruptions in circadian rhythms
• Sleep debt


  Not getting sufficient sleep on a chronic basis, leading to decreased alertness and mental efficiency
• Since the advent of electric light, the amount of sleep people get has declined
• Consequences of sleep deprivation


  • Decreased mental alertness and cognitive function
  • Depression-like symptoms
  • Obesity
  • Increased blood pressure
  • Increased stress hormones
  • Reduced immune function
• Sleep deprivation affects cognitive and motor function as much as, if not more than, alcohol intoxication
• The most severe effects of sleep deprivation occur when a person stays awake for more than 24 hours, or following repeated nights with fewer than four hours in bed
• By the time we are 65 years old, we average fewer than 7 hours of sleep per day
• Sleep


  Characterized by low levels of physical activity and reduced sensory awareness, regulated by circadian and homeostatic mechanisms
• Sleep-wake cycles


  • Controlled by multiple brain areas acting in conjunction, including the thalamus, hypothalamus, and pons
• Sleep rebound


  The fact that a sleep-deprived individual will fall asleep more quickly during subsequent opportunities for sleep
• Hormones secreted during sleep

  • Melatonin
  • Follicle stimulating hormone (FSH)
  • Luteinizing hormone (LH)
  • Growth hormone
• Evolutionary psychology


  A discipline that studies how universal patterns of behavior and cognitive processes have evolved over time as a result of natural selection
• There is little research that supports the hypothesis that sleep is essential to restore resources expended during the day
• The relationship between predatory risk and sleep is very complex and equivocal
• Cognitive function of sleep

  Sleep is important for cognitive function and memory formation
• Sleep deprivation results in disruptions in cognition and memory deficits
• Slow-wave sleep after learning a new task can improve resultant performance on that task and seems essential for effective memory formation
• Getting the optimal amount of sleep has been associated with increased capacities for creative thinking, language learning, and inferential judgments
• Beta waves


  Brain wave activity dominant when awake, have highest frequency (13–30 Hz) and lowest amplitude, show more variability
• REM sleep


  Characterized by darting movements of the eyes under closed eyelids, brain waves appear very similar to wakefulness
• Non-REM (NREM) sleep


  Subdivided into three stages distinguished from each other and from wakefulness by characteristic patterns of brain waves