States of Consciousness

The Restorative Theory of Sleep

Sleep is necessary for healing and immune health

The Adaptive Theory of Sleep

Sleep allows us to save energy for when we most need it, aiding in survival

Memory consolidation

Sleep is a time to store and consolidate memories

Jenkins & Dallenbach (1924)

2 participants learned lists of items, then recalled items after 1, 2,4, or 8 hour periods of sleep or wakefulness.

Jenkins & Dallenbach (1924) Results

Recall of the learned lists of items was much better after sleep

Skill Practice

Sleep may allow us to improve skills (even motor skills)

Walker et al. (2002)

Participants were taught to rapidly hit keys in a sequence then tested after 12 hours of sleep or no sleep

Walker et al. (2002) Results

Participants showed major task improvement after sleep

The Circadian Rythm

The body’s approximately 24 hour cycle of sleep and wakefulness that is controlled by about 20,000 neurons in the hypothalamus

After dark the brain releases

The hormone melatonin

How much sleep do newborns need?

approximately 16 hours a day

How much sleep do college students need?

7 to 10 hours a night

How much sleep does <1% of people need?

Due to a genetic mutation that allows people to function with a small amount of sleep, some people only need 6 hours

Short term consequences for sleep deprivation

Feeling edgy, Irritability, Difficulty concentrating

Long Term Consequences of Sleep Deprivation

Depression, learning deficits, slow reaction time, hallucinations

REM

Raid eye movement sleep, stage where eyes move around closed eyelids, where brain activity is similar to when awake, and where dreams are twice as likely to happen

REM Rebound

An increase in the amount and intensity of REM that occurs after lack of REM sleep for a few nights

Freuds Dream Protection Theory

During sleep, the ego is less able to control urges. Dreams stand as wish fulfillment and disguise wishes into symbols

Challenges to Freuds dream protection theory

Most dreams are negative, and most dreams don’t seem to be disguised

Activation Synthesis Theory

The brain produces random and chaotic signals during sleep, and dreams are the brains attempt to interpret these signals.

Activation Synthesis Theory challenges

Dreams are not always bizarre

Neurocognitive Perspectives on Dreaming

Random neural signals cant tell the whole story of dreams, and dreams are meaningful cognitive constructions that reflect everyday lives and concerns

Use of Hypnosis

Enhances effectiveness of psychodynamic and cognitive behavior therapies, reduces experiences of pain, can be useful in treating addiction, however it only works if you think it will work

Individuals chosen as volunteers at hypnosis shows are

easily influences, highly suggestible, under large social pressure to entertain

Psychologist have not identified

any unique psychological or neural marks hypnosis

Hypnosis and Memory

Does not improve memory, and may increase recall but much of it is inaccurate. May increase a witnesses confidence in inaccurate memories

Sociocognitive theory of hypnosis

Hypnosis is not a trance or unique state of consciousness. Beliefs and expectation shape responses

Dissociation Theory

Hypnosis creates a division of consciousness, hides the part of us that feels pain, and bypasses our sense of control over our own behavior.