PSYX 100 1st Edition Lecture 12 Outline of Last Lecture I Consciousness II Consciousness and Brain Activity Outline of Current Lecture I Biological Rhythms II Circadian Rhythms III Sleep IV The Sleep Cycle V Functions of Sleep VI Age Culture and Sleep Current Lecture I II Biological Rhythms a Biological rhythms are patterns behaviors that are engrained in us b Cycles create fluctuations in physiology i Annual cycles yearly SADS seasonal ii 28 day female menstrual cycle iii 24 hour hunger blood pressure urine production iv 90 minute sleep cycles Circadian rhythms a 24 hour cycle in humans and other species b Influential in sleep and productivity c Physiological changes body temperature blood pressure hormonal secretions etc d Creates an optimal time for sleeping and working e Light plays a key role i Receptors in our retina that send signals to the pineal gland ii Melatonin adjusts our biological clocks and makes us sleepy f Ignoring Circadian Rhythms disrupting circadian rhythms affects sleep quality These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute III i Can be caused by jet lag work shift rotations etc g Realigning Circadian Rhythms i Melatonin supplements ii Light treatments timed exposure to bright lights that helps people to more quickly adopt a new sleep cycle iii Shift scheduling schedule for progressively later starting times more time between shift changes Sleep a Studying Sleep i Electromyograph EMG records muscular activity and tension ii Electrooculograph EOG records eye movements iii EKG measures heart contractions iv Other instruments are used to measure breathing body temperature and many other things b Stages of Sleep i 5 Stages of Sleep ii On average takes about 25 minutes to fall asleep c Stage 1 Theta Waves i Lasts for about 7 10 minutes ii Deep relaxation mimics meditation iii May experience vivid images resembling hallucinations sensory experiences that occur without the presence of a stimuli iv Sensation of falling v Decline in heart rate respiration and body temperature d Stage 2 Sleep Spindles i 10 25 minutes ii Brief bursts of higher frequency sleep waves occur these are called sleep spindles iii Sleep talking commonly occurs during this stage iv Brainwaves slowly become higher in amplitude and lower in frequency as a person descends into slow wave sleep v Continued decline in heart rate respiration muscle tension and body temp e Stage 3 Slow wave Sleep i Stage 3 is a quick transitional stage into stage 4 there are less delta waves in stage 3 than in stage 4 ii High amplitude and low frequency delta waves occur iii Takes about 30 minutes to reach and lasts for about 30 minutes iv Bed wetting and sleep walking in children usually occur towards the end of this stage v Cycles reverse back up to lighter stages of sleep f Stage 5 REM Sleep IV V VI i REM rapid eye movement ii Marked by irregular eye movements breathing and heart rate iii EEG waves resemble beta waves iv Sleeper is basically paralyzed v 80 of dreaming occurs in REM The Sleep Cycle a We cycle through sleep stages about 4 times per night b REM periods get progressively longer throughout the night c REM sleep is about 20 of total sleep d Sleep hygiene different factors can affect the quality of sleep we get the following factors are some of examples i Eating sugar ii Drinking caffeine and alcohol are linked to poor sleep quality iii Light iv Temperature v Interruptions vi Stress vii Anxiety viii Rituals ix Putting brain to rest getting rid of technology and similar stimuli Functions of Sleep a Not much is known about why we need sleep but here are some helpful functions b Sleep conserves energy c Sleep provides protection from exposure to danger dark is danger d Sleep repairs and restores our mind and bodies and makes them reinvigorated e Sleep increases learning by consolidating memories f Sleep aides in growth think about how much babies sleep and how much they grow in such a short amount of time Age Culture and Sleep a Age trends in sleep i Newborns sleep about 16 hours a day 1 REM sleep 50 2 REM declines to about 30 in the first year ii Adults REM sleep 20 1 Slow wave sleep gradually declines 2 Stage 1 gradually increases increase greater in men iii Average total sleep declines with age b Culture and sleep i Nightly sleep is cross cultural ii Co sleeping is the world norm but is discouraged in urban western cultures there is no known consequences 1 Co sleeping the practice of parents and children sleeping together iii Siesta cultures 1 2 hour mid day nap 1 More prevalent in tropical areas during the hottest part of the day or after the biggest meal 2 Not practiced in industrialized societies