Unformatted text preview: 2/9/07 Psych 2 Psych 2
Principles of Psychology Christopher Gade Office: 5315 Tolman Hall Office hours: MW 2:003:00 Email: [email protected] Lectures: MWF 3:004:00, 100 GPB • In today’s lecture, we’re going Sleep Sleep to talk about one type of altered consciousness… sleep.
– – – Biological theories Evolutionary theories Cognitive theories • We’ll first discuss why we sleep. • Then we’ll cover what causes us to become tired. • After that, we’ll discuss the different stages of sleep. The Purpose of Sleep The Purpose of Sleep
• The Repair and Restoration Theory:
– The purpose of sleep is to enable the body to recover from the exertions of the day. – But what needs to recover??? • Muscles • Brain systems – The Randy Gardner exception • The Evolutionary Theory: – Evolution equipped us with a regular pattern of sleeping and waking for the same reason… to conserve fuel and to prevent us from walking into dangers. – What would the purpose of functioning at night be? • Little visual capabilities • Scarce resources and opportunity to find food. • Dangerous predators • A huge amount of energy is required to maintain alertness and – What about today’s world? • Lighting is available • Resources are abundant • Fewer/no predators • Equal amounts of energy are required in both day and night in – Does this difference support or refute the evolutionary theory?
order to maintain alertness and function well in the night to function well in the night environment. • Information Consolidation Theory:
– Our need for sleep is a result of the brain’s need to consolidate the information obtained throughout the day into memories. – What’s the proof? • High levels of brain activity during sleep • Increased levels of learned responses • Ferret maze experiment – Is there any proof against this theory? • Memories can obviously be established without sleep • Brain activity measures taken during human sleep seem extremely random. What causes us to become tired? What causes us to become tired?
• One of the main causes of our sleep pattern is based on our circadian rhythms.
– Circa: about a day – Circadian rhythms effect our heart rate, body temperature, and brain functioning • Our bodies are also influenced/reset by the sun every day.
– Question: is this biological or psychological? • Looking at uncommon situations involving sleep tells us a lot about how our body functions.
– The “cave” experiment • Social constraints • Sleep debt What are some other possible What are some other possible causes of the need to sleep? – “morning” and “evening” people • Physical exhaustion • Learned responses What happens while we sleep? What happens while we sleep?
• In the mid 1950’s researchers discovered that during sleep, people display an extremely unusual pattern of behavior several times throughout the night. • REM (rapid eye movement) or paradoxical sleep.
– Question: 1950’s??? • From this REM discovery, researchers began observing and defining the different sleep “cycles” that we go thorough. Measures of Sleep Measures of Sleep
• EEG (electroencephalograph) • Polysomnograph • Video recordings • Intermittent waking • fMRI The Stages of Sleep The Stages of Sleep
Awake Sleep stages 1 2 3 REM 4 0 1 2 3 4 5 6 7 Hours of sleep Stage 1 Stage 1
• brain waves patterns that closely resemble waking patterns. be woken. • Attentive to outside stimuli and can easily • Will report still being awake when woken in this stage. • Later replaced by REM sleep after the first sleep cycle of the night. • Brain waves begin emitting “sleep spindles”. These spindles are random bursts of high amplitude EEG waves. asleep. Stage 2 Stage 2 • People woken in this stage report having been • Dreams can also occur in this stage, but they are rare. • This stage makes up the majority of our sleep after the first two sleep cycles that we go through in a night. Stage 3 Stage 3
• This stage is represented by very slow and erratic brain waves. • This is commonly the deepest level of sleep most people will get after people go through their first two stages of sleep. recuperative effect on the body. • Believed to have some form of • The deepest level of sleep that we encounter. It is represented by long, slow waves on EEG measures. Stage 4 Stage 4 • Very difficult to wake people in this stage. • The stage of sleep that a lot of little children are in while they sleep walk. sleep. • Occurs only in the first (or first two) cycle(s) of • Considered THE recuperative stage of sleep for our bodies. Stage 5 (REM) Stage 5 (REM)
• AKA paradoxical sleep • The majority of our body is paralyzed during this stage. However, some body parts (eyes) are highly active. • REM sleep and stage 2 sleep are the two most common REM sleep. regulation. stage. stages of sleep after we experience our first two sleep cycles. • Neural activity that resembles a waking state occurs during • Associated with memory consolidation and emotion • The majority of our dreams are believed to come from this – Waking experiments • NO!!! Is this sleep cycle pattern the same across all ages? • As we age, or sleep patterns change immensely. • In addition to that, the proportion of sleep stages varies widely depending upon the age of the person.
– – – – Fetus Children Adults The Elderly What does this difference in sleep What does this difference in sleep patterns across age tell us?
• It might give us insight into the function of different sleep patterns. of sleep. • It might tell us about the value and purpose • It might give us insight into the development of the brain. this means. • In truth, we really don’t know exactly what • These sleep cycles and theories of sleep do not depict an exact replication of everyone’s sleep patterns. Added Notes: Added Notes: • Each individual’s sleep patters vary from the population as a whole, and their sleep need vary as well (some of us need a lot, some of us need a little). sleep patterns of a number of individuals in the population at some point in time during their lives. • Various sleep abnormalities have a strong impact on the • Read up on these sleep abnormalities (insomnia, sleep apnea, narcolepsy, sleep talking, sleepwalking, nightmares, and night terrors), because they are not only interesting, but they give us insight about what might go awry with our typical sleep patterns. ON TO DREAMS!!! ON TO DREAMS!!!
• Now that you understand how we sleep, and possibly have a good understanding of why we sleep, we’re going to explore the most popular psychological aspect of sleep… DREAMS. content, but the different theories about why we dream, and what is actually going on in our dreams. come ready to learn. • In the lecture next we’ll not only discuss dream • Its going to be a little fast paced and weird, so ...
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