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Sleeping and Dreaming. Circadian Rhythm. The pattern of fluctuations in bodily processes that occur regularly each day. Includes; sleep-wake cycles, body temperature, hormonal secretions, blood pressures and heart rate. These patterns are synchronized with the 24 hour cycle of day and night.
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Circadian Rhythm • The pattern of fluctuations in bodily processes that occur regularly each day. • Includes; sleep-wake cycles, body temperature, hormonal secretions, blood pressures and heart rate. • These patterns are synchronized with the 24 hour cycle of day and night
Suprachiasmatic Nucleus (SCN) • This part of the hypothalamus known as the SCN regulates our sleep-wake cycles. • The SCN regulates the pineal gland which releases the hormone melatonin.
Melatonin • Melatonin helps regulate the body’s sleep-wake cycle. • Exposure to darkness during evening hours activates the production of melatonin, making us sleepy. • Duringlightexposure, melatonin production falls off, which keeps us awake.
Things that affect our sleep patterns • Cloudy Days- lack of light increases melatonin levels, making us sleepy. • Time changes- People may feel sluggish during the first few days after time changes (forward or backward). • Frequent time shifts- Frequent time shifts can throw off the circadian rhythm
Jet Lag • Change in local time conflicts with your internal body clock • Fall asleep earlier than usual (traveling from east to west). • Associated with irritability, fatigue, difficultyconcentrating, diarrhea, headache, milddepression. • Recovery can take one day per time zone crossed.
Functions of Sleep • Protective: Keep you out of harm’s way (esp. animals) • Conserve Energy: Lower body temp. at night helps keep body temp. up during the day. • Restorative: Replenish proteins and help brain recover from wear and tear of the day.
Functions of Sleep • Consolidation: Newly formed memories can be turned into lasting remembrances. • Fight Disease-causing Agents: More susceptible to common ailments due to lack of sleep
Functions of Dreams • REM sleep is consolidating fresh memories into lasting ones (Huber et. al.). • Dreams help us sort through everyday problems and concerns (Hartmann). • Activation-synthesis Hypothesis: Dreams represent an attempt by the cerebral cortex to make sense of the random discharges of electrical activity that occur during REM sleep.
Activation-Synthesis Hypothesis • According to this, the cerebral cortex creates a story line based on the individual’s store of knowledge and memories to explain the random signals and emotions and sensory experiences they generate.
Parts of Brain • Areas in the brainstem that involve emotions, memory and visual processing are activated during REM sleep. • Areas of the brain involved in logical thought show decreased activity during REM sleep. • This is why dreams may lack order or ordinaryconscious thought.
Freud • Believed dreams represent a form of wish fulfillment. • Dreams contain symbols that represent the sleeper’s underlying wishes, usually of a sexual or aggressive nature. • Called dreams, the “royal road” to the unconscious mind, but you need a psychological road map to determine their true meanings.
Types of Dream Content • Freud distinguished between 2 types of dream content. • Manifest Content: Manifest content refers to events that occur in the dream.
Types of Dream Content • Latent Content: The true, underlying meaning of the dream, disguised in the form of dream symbols. • The disguise conceals the dream’s real meaning, helping you stay asleep instead of being awakened by emotionally threatening material.
Example • Manifest Content: Having a dream where you get pulled over by a police officer for speeding and receive a ticket. • Latent Content: Driving fast may symbolize an unacceptable sexual wish. The police officer, a symbol of authority, might represent your father punishing you for having the sexual wish.
More Freud • Phallic objects like; trees, skyscrapers, snakes, and guns are symbols of male genitalia. • Enclosed objects like; boxes, ovens, closets are symbols of female genitalia • Sometimes though, “a cigar is just a cigar”…
Lucid Dreaming • Lucid dreams are dreams in which the person is aware that they are dreaming. • Relatively few people report experiencing lucid dreams regularly. • Some people claim to be able to control what they will dream about and direct the action of their own dream.
Sleep Deprivation • Most people need between 7-9 hours of sleep to feel fully rested. (Americans-6.9) • 1 in 4 people say that sleep problems impair their ability to function during the day. • High School students: Only 15% get the 8.5 hours recommended.
Sleep Deprivation • Lack of sleep can; • Slow reaction time • Impair concentration • Impair memory • Impair problem-solving ability • Make it more difficult to retain newly acquired information • Impair academic performance
Sleep Deprivation • Sleep deprivation is among the most common cause of motor vehicle accidents. • Loss of REM sleep affects learning ability and memory. • Prolonged sleep deprivation can lead to hypertension, a cardiovascular disease and potential killer.