Sleep If we live to 75 we would have spent 25 years sleeping including 5 years dreaming Studying sleep Sleep Laboratories rooms are home like. They found Different stages which we progress through in a repeated way. Known as REM and NREM(1,2,3,4,) B2KKpY Methods used to study sleep Physiological measures: objective All detect amplify and record electrical activity DARE (this needs to be stated at the start of every answer) 1) Electroencephalograph (EEG) -DARE electrical activity of the brain and produces brainwaves. -EEG: patterns for each stage Name of Wave Looks LikeStage of Sleep Beta LikeHighest frequency Lowest amplitude Awake / Busy And REM sleep (dreaming) AlphaLower than Beta Frequency, slightly higher amplitude than Beta Stage 1 ThetaLower frequency than first 2 (B&A) Some high and low amplitude End of stage 1, all stage 2, and start of stage 3 DeltaLowest frequency, Highest Amplitude End of stage 3 and all of Stage 4 Stage of sleepBrain Waves REMBeta Like NREM 1Alpha + Theta NREM 2Theta NREM 3Theta + Delta NREM 4Delta How can we remember this? BATheD - Beta, Alpha, Theta, Delta B = A= T= D= 2) Electromyograph (EMG) (m = muscles) DARE electrical activity in active muscles. -REM = Very little or no electrical activity (Muscle paralysis) = tension -NREM = Some muscle electrical activity recorded 3) Electrooculargram (EOG) DARE electrical activity in the muscles that control the eyes -REM = Rapid movements -NREM = Little/no movement Others -HR measured by an electrocardiogram (decreases in NREM, increases REM) -Body Temp = drops around 1 degree while we sleep Ways continued 4) Video monitoring: sleep walking, talking, tossing, hours to fall asleep 5) Sleep-reports: - Subjective 6) Sleep diary/log: record of an individuals sleep and waking activities over weeks. - Used in conjunction with the other methods because -Dishonesty -Forget -Cant describe their experiences in words -Above are least reliable NameWhat it measuresREM v NREM EEG Detects, amplifies & records electrical activity in the brain REM = Beta Like NREM = Alpha, Theta and Delta EMG Detects, amplifies & records electrical activity of muscles REM = Little/no movement NREM = some movement EOG Detects, amplifies & records electrical activity of eye muscles REM = Rapid/lots of NREM = little XS7ujM ways to measure sleep/States of Chttp://www.youtube.com/watch?v=VpR1C XS7ujM 2 stages of sleep 1)Non rapid eye movement (NREM) 2)Rapid eye movement (REM) Typical sleep for adults = 8 hours: (80% NREM and 20% REM) Babies = 18 hours (50% of each) Stages of sleep There are 45 continuous sleep cycles per night Each sleep cycle (REM & NREM) lasts 80100 mins Approximately 80% of adult sleep is NREM REM gets longer as the night progresses NREM gets shallow as the night progresses Key terms Circadian rhythm occurs once a day. E.G= sleep wake cycle, body temp, production of melatonin Ultradian rhythm = occurs more than once a day. E.G = breathing, heart rate, sleep its self The picture shows that REM gets longer and NREM sleep stages get shallower as the night progresses NREM sleep 80%for adults Four stages: light deep sleep First half of night has more NREM sleep EMG = movement EOG = no movement EEG = NREM 1 = Alpha / Theta NREM 2 = Theta NREM 3 = Theta / Delta NREM 4 = Delta Hypnogogic state pre-sleep + alpha waves + slow rolling eye movements Stages of Sleep within NREM Stage 1 -Drift in and out -Hypnic jerk jerking sensation/falling -Decrease in HR, respiration and body temperature -Alpha Waves followed by irregular theta Waves (as we move stage 2) -If woken we feel like we have not been asleep Stage 2 -Easily woken, however it is the stage when we first are truly asleep -Theta Waves + sleep spindles + K complexes Sleep spindles = brief bursts of high frequency which is an indicated the person is truly asleep K complex = single burst of high amplitude in response to arousing stimulus Stage 3 -HR, respiration, body temperature all continue to fall -Mixture of theta and delta (delta = moving into stage 4 marks the beginning of Slow Wave Sleep SWS) Stage 4 SWS -Deepest stage -Muscles are relaxed -Delta Waves: Difficult to wake -Less and less time spent in stage 4 as night goes on -If woken feel confused sleep inertia A single sleep cycle looks like REM23432REM 2REM (later in the night = shallow) REM (dreaming) known as paradoxical sleep Rapid Eye Movement Paradoxial = brain is active while body is inactive EEG = Beta Like Waves 20% for adults (50% for babies) Time when most dreams occur (can occur in all stages however) EMG = little/muscle paralysis atonia Low muscle tension EOG = Rapid eye movement High muscle tension Breathing and heart rate are faster REM periods lengthen as the night progresses Note Can dream in NREM but are less frequent less memorable less vivid Summary During an 8 hour sleep period, we experience four or five complete cycles of sleep consisting of NREM and REM sleep periods. Generally a complete cycle lasts for min. NREM has four distinct stages and stages 3 and 4 (deepest sleep) may disappear as morning approaches. Some people think of REM as the 5 th stage of sleep. As sleep progresses, periods of REM sleep tend to get longer and closer together. Key features of NREM sleep Stage 1: a light sleep, commonly experience hypnic jerk Stage 2: a light sleep, sleep spindles & K complexes Stage 3: a deep sleep, Stage 4: deepest sleep, sleep inertia experienced if woken. _6fkRs summary of REM and NREMhttp://www.youtube.com/watch?v=a3ONM _6fkRs-HrM EEG and stages of sleephttp://www.youtube.com/watch?v=zI_hdRd -HrM StageEEG Pattern Alert and REM sleepBeta Stage 1Alpha + irregular theta towards the end moving into stage 2 Stage 2Theta with sleep spindles and K complexes Stage 3Theta with delta (marks the beginning of slow wave sleep and entering stage 4) Stage 4Delta only During Stage 1 sleep, a person A. is more likely to dream than during other stages. B. is often difficult to wake up. C. has a very low body temperature. D. may experience very brief muscular contractions. Stage 3 sleep primarily consists of A. beta and theta waves. B. theta and delta waves. C. alpha and delta waves. D. alpha and theta waves. Recordings from an electromyograph (EMG) can distinguish between rapid eye movement (REM) sleep and non-rapid eye movement (NREM) sleep because there is A. never any movement of the muscles in REM sleep, unlike NREM. B. never any movement of the muscles in NREM sleep compared to REM. C. an increase in movement of the muscles in REM sleep compared to NREM. D. an increase in movement of the muscles in NREM sleep compared to REM. Students who chose option A must be extremely wary of choosing absolute statements. The EMG measures electrical activity in muscles of the body whereas the EOG is used to measure electrical activity in muscles that control eye movement. Patterns of sleep over the life span Newborns -REM = 50% allows connections in brain to be formed hours = newborn -12 13 hours = 1 year old Children - sleep pattern is ideal - 8 12 hours sleep Adolescence = significant changes -Total time is shorter = sleep debt -Sleep-in more (weekends) -Increase in day time sleepiness -Need 9-10 hours but usually only get 8 Sleep-wake cycle shift during adolescence Why: a mismatch between internal biological cues (hormones) and external environmental cues (presence/absence of sunlight, alarm clocks, meal times, phones) to go to sleep at night. :Teenagers = Delayed Sleep Phase Syndrome : InvolvesInvolves delay in the time a person falls asleep a tendency to want to sleep-in longer in the mornings. increase in daytime sleepiness Note: Combined with a delayed onset of sleep, teenagers commonly experience a reduced total sleep time during the week. On Saturday and Sunday, many teenagers sleep-in to catch up on the sleep they lost during the week. However, experiencing a later rise time on two days over the weekend can make it extremely difficult for a teenager to get up for school on Monday morning. Consequences Greater daytime sleepiness impairs cognitive functioning and achievement at school. Lower achievers compared to higher achievers: sleep less hours a night experience greater number of awakenings from sleep report more daytime sleepiness experience greater weekend delay = having a later bed- time and a later rise time on Saturdays and Sundays compared to weekday Why does this happen A) social and B) biological factors A) Social factors - homework, - go out with friends, - after-school sporting activities, - part-time employment, - technology in bedrooms Biological 1) Melatonin: is a hormone associated with the onset of sleep. It has been found that from the beginning of puberty, melatonin is secreted later in the evening which means that they fell tired later. Overall In adolescence, the release of melatonin occurs later in the day and as a result creates -Delayed sleep onset which leads to -Reduction in sleep each night = sleep debt Circadian rhythm is linked to external cues such as daylight, meal times, and alarms. Hormones are also produced in a cyclical pattern to control bodily functions such as the release of melatonin. Q: But how is a sleep-wake cycle different during adolescence? Sleep-wake cycle during adolescence Q: But how is a sleep-wake cycle different during adolescence? Adolescents typically have irregular sleep patterns Adolescence shifts the body clock backwards 1-2 hours resulting in sleep phase onset This results in an accumulation of a sleep debt. Adults -Sleep wake cycle shifts back to normal time -Sleep between 5-10 hours -Less time in stage 3 and 4 Elderly hours per night -Sleep shallow (may not even enter stage 3 and4) Purpose of sleep A person who never sleeps has yet to be identified which suggests that everyone sleeps. Sleep is Automatic 1) Restorative Theory -NREM = physical growth and repair (cell waste, fatigue, neurotransmitter replenishment) -REM = brain development/neural connections (higher mental functions such as learning and memory) -NB = research shows ppl who exercise have more deep sleep (NREM). Limitation - Why dont inactive individuals sleep less than active individuals ? 2) Survival (Evolutionary) Theory of Sleep -When we sleep we are less noticeable/ wont attract the attention of preditors -Once an organism has fulfilled all its survival functions such as eating, drinking, caring for its young and reproducing, it must spend the rest of its time conserving energy, hidden and protected from predators -Conserve energy to fight during the day -Limitation = lose awareness of our surroundings therefore become more vulnerable. Restorative theory = understand why we sleep Survival theory = understand sleep patterns of different species Sleep Deprivation Inadequate or poor quality sleep It can be 1)Partial (small amount in a 24 hour period) most common 2)Total (none at all) 3) Selective Psychological effects: consequences on mental abilities and cognitive functions Physical effects: consequences on bodily functions and behaviours. Partial Psychological: * irritability * moodiness * difficulty with boring tasks * shortened attention span *impaired memory * In thinking positively and solving problems Physiological: felling tired muscle strength reduced lack of energy/reaction times droopy eyelids, difficulty focusing the eyes, slurred speech hand tremors heightened sensitivity to pain They are temporary and minor Total Psychological: * depression *hallucinations (3 days or more) *delusions *paranoia Physiological * decrease in body temperature * functioning of the heart and respiratory systems. * risk of diabetes, obesity, heart disease and high blood pressure increase. * decreased efficiency of the immune system, resulting in an inability to fight disease and infection No lasting effects Note: on an exam they usually wont specify between partial and total sleep deprivation effects. Physical sleepiness aches and pains in body fatigue micro-sleeps hand tremors drooping eyelids difficulty focusing eyes lack of energy and strength slurred speech increased sensitivity to pain slower heart rate and respiratory rate drop in body temperature slower reaction time. Psychological lack of concentration shorter attention span irritability/moodiness anxiety lack of motivation impaired memory processes depression delusions paranoia decline in ability to perform simple tasks irrational/illogical thinking. These are all temporary. Symptoms are reversed by a single nights sleep. Effects on tasks from research show Simple/boring tasks Make more mistakes Driving on a free way at night Complex/interesting tasks No increase in the number of mistakes Exam Research has found that 30% of road accidents occur when drivers fall asleep on long boring stretches of road. Total Sleep Deprivation: unethical to conduct experiments on humans. Rats who have been totally deprived of sleep eventually they died after 2-3 weeks of no sleep. Immune system collapsed resulting in blood poisoning uses convenience samples therefore not truly representative of entire population No long term effects no Reasons for no long term effects of total sleep deprivation 1) Microsleep: very short period of sleep that occurs while the person is apparently awake. EEG pattern = early stage of NREM sleep (Alpha). person having no recollection. involuntary 30 sec eyes could be open Microsleeps are prevalent when people who are sleep deprived complete monotonous tasks. 15 minute power naps are suggested 2) REM rebound: woken up in REM. However once allowed to sleep uninterrupted = spent more time in REM sleep. Doesnt have to be the next night. REM rebound = sleeping more in REM the next time after being deprived of it. 3) Amount of sleep: usually only takes 1-2 nights to catch up on sleep. Loss of REM and NREM sleep REM SleepNREM sleep More serious effects than NREM more aggressive experiencing greater difficulty to concentrate anxiety, feelings of insecurity, poor learning memory consolidation REM rebound hinder the restoration of the body and its efficiency to replenish energy stores. (Growth hormone is released in NREM sleep) 6PgmG4 sleep deprivationhttp://www.youtube.com/watch?v=pOH1Q 6PgmG4 Renee is extremely tired, due to lack of sleep the previous night. As a result, she is more likely to experience difficulty in performing ___________ tasks while her ability to perform _________ tasks will probably be unaffected. A. simple; complex B. complex; simple C. verbal; nonverbal D. nonverbal; verbal Questions Brain Waves How many are there? What brain wave is associated with REM sleep? What brain wave has the highest amplitude and lowest frequency? What stage of sleep are they associated with? What 2 brain waves does stage 1 experience? How many are there? 4 What brain waves are associated with REM sleep? Beta What brain waves have the highest amplitude and lowest frequency? Delta What stage of sleep are they associated with? Stage 4 What 2 brain waves does stage 1 experience? Alpha and theta What brain waves are associated with stage 1 sleep? What 2 brain waves are associates with stage 3 sleep? What brain waves happen when we are active? What 2 unusual things happen during stage 2 sleep? What brain waves are associated with stage 1 sleep? Alpha and Theta What 2 brain waves are associates with stage 3 sleep? Theta, delta What brain waves happen when we are active? Beta What 2 unusual things happen during stage 2 sleep? Sleep spindles and k complexes What happens to REM as we get older? What happens to total hours of sleep as we get older? What happens to NREM sleep as we get older? Outline the characteristics of REM sleep? EMG = EOG = EEG = Heart rate = AT what stage might one best recall dreams? What purpose does REM sleep appear to serve as opposed to the apparent function of NREM? Q1 Two of: memory disruptions or distortions, perceptual and cognitive distortions, change in emotional awareness, altered perception of pain, less or more self-control, distorted sense of time, decreased level of awareness, less limitation on content. Two of: increased heart (pulse) rate, increased body temperature, increased GSR, changes to brainwaves in EEG, changes to muscle tone (increased/decreased electrical activity on EMG), increased respiration rate, slower reaction time. Q2 Washing dishes and singing along to the radio. They can be done together because one or more of the tasks has become an automatic process (it does not need a lot of mental effort and is well practiced). The example had to suggest two tasks, one of which was not complex. Many students referred to driving a car and talking on a mobile phone. While talking is not complex, it is emphasised that research has shown that it is not possible to perform these tasks at the same time without losing proficiency in either or both of them even if using a hands-free phone. Q3 His GSR reading will be higher than in a normal state. Increased sweat on the skin increases the electrical conductivity of the skins surface, so the galvanometer will register a higher reading. Many students answered the question as if they were referring to any altered state of consciousness, disregarding the fact that the question specified heightened arousal. Q4 Meditation sensations or perceptions are dulled (for example, pain), distorted perception of time, awareness of external environment is reduced Hypnosis distorted perception of time, sensations or perceptions are dulled (for example, pain), loss of awareness of self, can increase self control (for example, quitting smoking),more suggestible, so less inhibited From drug use thought processes are disorganised sensations or perceptions are dulled or heightened memory impaired more/less/inappropriate emotional reactions distorted perception of time, lack of self control dreaming/daydreaming thought patterns are disorganised distorted perception lack of control of movements sensations and perceptions are dulled Q5 Driving is a complex task, a controlled process that requires selective attention. In attempting to perform these two tasks at once, Yusef would be using divided attention and would not be able to concentrate sufficiently on driving, thus causing danger. Students needed to refer to both attention and processing in order to score full marks for this question.