SLEEP EEG TODAY Mummy, I Cant Sleep! What you need to Know Two theories about the function of sleep What happens during sleep and how this might relate to function.
Predictions Generated by each theory Evidence and evaluation points for each theory Evaluation using a possible THIRD theory Objectives Slides 5 11 (plus text p148 & 154) Mini-test To know the stages of sleep (1-4 +REM) and brain activity related to each one
To be clear about the difference between REM and NREM Sleep To be able to describe Restoration Theory of sleep with supporting evidence. Qu. What are the sleep stages? Awake 1
EEG stages 2 3 REM 4 0
1 2 3 4 5 Hours of sleep
6 7 Qu. How do we measure sleep? Electro-encephalogram (Electrical Activity) Electro-oculogram (Eye Movement) Electro-myogram (Muscle tension) Brain Waves and Sleep
Stages Stages 1 & 2 Relaxed state easily woken Heart rate slows & temperature drops Alpha & Theta waves Sleep spindles (stage 2) Brain waves are quite fast Stages 3&4 Slow Wave Sleep
Deeper Sleep harder to wake Heart rate slows further Temperature keeps dropping Some slow Delta Waves (50%+ in stage4) Metabolic rate lowest Growth hormone produced
REM Sleep Paradoxical Sleep Brain active - body paralysed Faster waves like waking Increase in oxygen consumption, blood flow and neural firing Rapid Eye Movements Hardest to wake from
Qu. Why do we Sleep? Restoration Model = Sleep allows us to recharge our bodies recover from fatigue and Evolutionary/circadian rhythm model Sleeps main purpose is to increase a species chances of
survival Mini-test To evaluate Restoration theory in two ways: Discussing supporting and opposing evidence Discussing the evidence that relates to the predictions of restoration theory
psychlotron.org.uk Objectives Slides 13- 27 (and text p155) Restoration Theory psychlotron.org.uk The function of sleep is to allow body to be repaired and restored
Oswald (1980) REM essential for brain recovery SWS essential for body repair The importance of SWS Growth Hormone is secreted during SWS Sassin et al found that when we sleep during the day and are awake at night the release of GH is also reversed.
This supports the idea that GH is linked to SWS Krueger et al (1985) found a link What is different about infant and old people sleep patterns? Importance of REM sleep BRAIN DEVELOPMENT In babies REM appears to be important for brain growth
Length of REM in a species related to maturity at birth Less mature at birth = more REM needed CHECK who needs more REM a platypus or a dolphin? Evaluate: Is this direct evidence? Importance of REM sleep NEUROTRANSMITTERS - Siegel and Rogawki (1988)
There is break in neurotransmitter release This allows neurons to regain sensitivity Support MAOIs increase levels of monoamines (eg serotonin and dopamine) Side effect REM is abolished Why? Increase in monoamines mean receptors dont need revitalising So no need for REM (Siegel 2003)
Importance of REM sleep MEMORY CONSOLIDATION REM consolidates procedural memory SWS consolidates semantic memory and episodic memory Stickgold (2005) Evaluation Relevant to Restoration Theory? How? Oswald Supporting evidence (1983) Found that tissue growth in skin
takes place more quickly when we are asleep. REM sleep is important for brain growth & repair. SWS important for bodily growth & repair. (1969) Patients recovering from drug overdoses. Significant increase in quantity of REM sleep which is indicative of recovery processes. EVALUATE- other possible conclusions? Plenary questions
How is sleep measured? What does Restoration theory say about the purpose of sleep? Give two reasons why SWS is important. What distinction does Oswald make about the purposes of REM and SWS? What evidence supports the idea Restoration theory
Deficits in functioning during sleep deprivation Rebound following deprivation Increase in REM during brain growth, reorganisation & repair Increase in SWS during illness, recovery from injury psychlotron.org.uk Main predictions:
Restoration theory Main predictions: Increased Exercise increased sleep: Shapiro (81) Supports How? Horne & Minard (85) opposed How? psychlotron.org.uk
Peter Trip Video Sleep deprivation experiments Peter Tripp radio DJ sleep deprived self for 200 hours. Randy Gardner - sleep deprived for 264 hours under supervision of sleep researcher Dement May have been getting
MICROSLEEP Rebound Not all lost sleep is reclaimed About 70% of lost SWS and about 50% of lost REM typically recovered Only REM and SWS sleep is necessary psychlotron.org.uk
Generally, people catch up on sleep following deprivation Illness & injury Total sleep time increases during illness REM increases during recovery from brain injury, ECT & drug withdrawal SWS deprivation can cause physical symptoms
psychlotron.org.uk Sleep does increase during illness and recovery from injury Test Why does Michael Corkes story strongly support restoration theory? What Shapiro et al find about the effect of increased exercise? What does the rebound effect show
about which types of sleep are important? What is REM sleep important for according to Stickgold? Objectives Slides 29- 39 and text p154 Mini-test To be able to describe evolutionary theory using the ideas of energy conservation, foraging requirements
and predator avoidance. To understand the theories of Webb and Meddis Evolutionary/circadian rhythm model Sleeps purpose = increase the chances of survival BRAIN DEVELOPMEN T
Ecological niche Species sleep patterns are different due to. BODY SIZE Qu. Do all animals sleep?
Mammal Giant Sloth Tree Shrew Cat, Hamster Mouse, rat, squirrel Hedgehog Humans, rabbit, pig Cow, Goat,
Hrs of sleep/da y 20 15 14 13 10 8 3
2 2 All mammals and birds sleep. Qu. Can you explain these differences? Qu. Do whales sleep?
Apparently so Qu. Do fish sleep? Apparently so Fish, reptiles and amphibians
have periods of inactivity SWS and REM sleep patterns in mammals Evolutionary Theory of Sleep
THREE KEY ASPECTS Energy Conservation Foraging Requirements Predator Avoidance (Waste of Time) Webb, (1982) Energy Conservation Hibernation Theory Sleep evolved to conserve energy Period of enforced inactivity - using less energy (Like hibernation) Important for animals with high
metabolic rates Foraging Requirements Sleep limited by food requirements Herbivores tend to eat large quantities of low nutrition food e.g grass and therefore need to eat a lot of the time less time for sleep. Carnivores eat more nutritious food so can spend less time foraging Carnivores generally sleep for
longer. Meddis, (1975) - Predation theory Sleep has evolved to help species adapt to threats. Patterns of sleep diversify across species due to environmental threats posed, leading to; Sleep pattern? Large predators =
Small vulnerable animals = Animals who cannot see in the dark = Meddis, (1975) - Predation theory Waste of time Hypothesis Sleep = avoid predators when most vulnerable Most animals = darkness + hidden Staying still with nothing better to do Siegel (2008) being awake is more dangerous
Sleep is for energy conservation + avoiding danger Best strategy for passing on genes = sleep for as long as you can get away with Lions can do little else but sleep for up to 2 days after a large kill Objectives Slides 42-54 and text p155
psychlotron.org.uk Mini-test To evaluate research on evolutionary theories of sleep To Develop an essay plan to answer the likely exam question Evidence Animals generally sleep more when
weather is cold and food is scarce (Berger & Phillips, 1995) However, no direct correlation between physical work done and sleep duration in humans (e.g. Horne & Minard, 1985) psychlotron.org.uk Sleep patterns are affected by energy expenditure & availability
Evidence Smaller animals tend to sleep more than larger (e.g. giraffe 1hr vs. bat 20hrs) Carnivores sleep more than herbivores (e.g. lion 16hrs vs. buffalo 3hrs) Some notable exceptions e.g. rabbit (small, herbivore) & human (much
psychlotron.org.uk Comparative studies of different species generally support evolutionary view Energy consumption issues? Marine mammals do not show REM sleep, perhaps because relaxed muscles are incompatible with the need to
come to the surface to breathe. In dolphins and birds, only one brain hemisphere enters SWS at a time the other remains awake. Test What is the purpose of sleep according to evolutionary theory? Why do differences in the sleep
patterns of species of animal support this? What did Meddis claim about the purpose of sleep? According to Webb why do carnivores sleep more than Evolutionary critiques? Qu. Can these ideas be tested? Qu. Does sleep serve the same function for all species?
Qu. Is sleep an adaptive process? Qu. What happens if we are deprived of sleep? Problems Does a bat get so much sleep because its small or because it has few predators? Why do animals with very different lifestyles have similar sleep patterns?
psychlotron.org.uk Many evolutionary significant factors could affect sleep patterns; theory doesnt tell us which are important Problems Why is sleep universal when in some species (e.g. dolphins) it would have
been an advantage to get rid of it? Why is sleep deprivation apparently fatal? psychlotron.org.uk Some features of sleep cannot be explained easily by the hibernation theory: RESTORATION OR ADAPTION?
Jim Horne (1999) asks Qu. If the body can repair itself under a wakeful state, what is the main purpose of sleep, physiological repair or neurotransmitter recovery? Qu. If REM is for neurotransmitter recovery, why do infants spend 50% of their sleep in REM, but by the first year they have half of that (when most learning occurs)?
Horne (1988) Core sleep consisting of SWS is essential for normal brain functioning. Stages 1-3 NREM and REM sleep are not essential. During core sleep the brain recovers & restores itself, but bodily restoration occurs during optional sleep & periods of relaxed wakefulness. Horne
(1997) SWS (more dominant in the first 6 hours of sleep) is biologically essential. In sleep labs participants deprived of sleep for 72 hours only needed 8 hours to restore powers of concentration. Most of the 8 hours is spent in SWS. People adapt to less sleep by sleeping more efficiently going to sleep faster, entering deep sleep faster and waking less in night Horne
(1997) SWS (more dominant in the first 6 hours of sleep) is biologically essential. EVALUATE HORNES METHOD AND FINDINGS how convincing are his conclusions? Horne (1999) - asks; Qu. What is the point of falling unconscious? Qu. Is sleep is purely restorative, why are there so many variations of sleep patterns across species?
Task Find one supporting and one opposing piece of evidence for each of the evolutionary purposes of sleep use page 154 to 155 and write down your findings. Test Explain why evolutionary theory contains a contradiction.
Why is REM sleep a problem when it comes to energy conservation? Why can research on different species of animal sometimes be flawed? What is a phylogenetic signal?
Digestion. Add 1 Drop of Lysozyme to your tube. Cap and gently mix by flicking a few times. Place your sample in the freezer overnight. I've done this for you!! You can definitely do it with your students! The lysozyme...
Thesis - create your own . For example- unfair social divisions. Create new sentence on unfair social divisions. Also, Gov. debt. Create new sentence on . Gov. debt. Moreover, unequal tax burden. ... Bryan Staples ...
May occur at any age, any tooth Most affect 8~9yr-old children and D , E , D , E PDL absent Occlusal, periodontal problems, impaction of the underlying teeth Treatment and Prognosis Variable : extraction, orthodontics, segmental osteotomy DEVELOPMENTAL ALTERATIONS...
Satellite in a circular orbit Work and Energy 2 B Work and Energy Forces Forces on a hammerhead Work and Energy S S23 Fn Work and Energy Spring Force (Hooke's Law) FS(x) = - k x FP FS Natural Length...
Do you want a ring or a necklace? Do you want to go outside now? Questions of Judgment (conflicting-systems) - Questions requiring reasoning, but with more than one arguable answer. These are questions that make sense to debate, questions with...
Understand practical use of the School Profile, Assessment Inventory, ACT Student Detail, NDSA Growth Model Roster, and NDSA Assessment Trend, Student Directory reports, and Developmental Courses by Subject Area, and District Developmental Courses ... PowerPoint Presentation Last modified by:
Isotopes, Ice Cores and Climate Change. Laura Marschke. Southwest Early College ... (δ18O ice) from the Greenland Ice Sheet Project II (GISP II) ice core over the last 80,000 years ... reflecting the waxing and waning of continental ice sheets...
Ready to download the document? Go ahead and hit continue!