Sleep and Dreaming The first 90 minutes after you fall asleep:
chapter 5 Realms of sleep Stage 1. Feel self drifting on the edge of consciousness Stage 2. Minor noises won’t disturb you Stage 3. Breathing and pulse have slowed down Stage 4. Deep sleep REM. Increased eye movement, loss of muscle tone, dreaming
Sleep and Dreaming For the rest of the night… stages appear out of order
Why sleep? Physical reasons: • Body clean-up: remove waste from muscles, repair cells, strengthen immune system, restore energy [no wonder we feel so awful when we don’t sleep!] • After 4 days of no sleep – feeling awful. Soon, infections and death.
Why sleep? Mental effects of missed sleep: • Increased cortisol (stress hormone) causes cell damage • Lowered attention, less flexible thinking, less creativity Mental effects of sleep: • “Consolidates” learning/memory…
Evidence for consolidating learning 3 groups taught a strategy for a high speed math task – then brought back 8 hours later for a test: Who found a hidden shortcut? • Evening lesson plus 8 hours sleep • Morning lesson plus 8 hours delay • Evening lesson plus 8 hours delay Sleepers did almost 3 times as well! Note: Deep (stage 3 and 4 and REM) most important. Don’t stay up all night to study! SLEEP!!!!!!!
Why dream? 4 theories • Unconscious wishes: Freud’s theory. Your ‘dreams can come true’ in your dreams. According to Freud, by studying our dreams we can figure out what we really want.
Why dream? 4 theories • Dealing with problems Your dreams tell a story about the problems that are bothering you most. • Students dream about missing tests. • Teachers dream about losing their lecture notes.
Why dream? 4 theories Cognitive (thinking) approach • Just like when you’re awake, except that there’s nothing to think about! • Evidence to support this: If people are cut off from all sensory input, their thoughts become dreamlike – disorganized, hallucinatory
Why dream? 4 theories Activation-Synthesis Theory (Making Sense of Nonsense) • During the brain’s clean-up work, visual cells fire – we feel like we’re “seeing” • The rest of the brain tries to tell stories that make sense of the random cell firing images
Why dream? 4 theories Which theory is right? • Freud’s theory mostly discounted, but could more than one theory be right? • e.g., In ‘making sense’ of random cell firing, we might tell stories we like to hear. • Could dreams in different stages serve different purposes? (Remember, dreams are longer and more vivid in REM, but we dream in other phases, too
Why insomnia? About 10% of adults have frequent problems getting to sleep or staying asleep • Worry • Work or school demands • Physical problems • Irregular schedules
Tips for Getting to Sleep • Are you sure you’re really not sleeping? Many people take up to 30 minutes to fall asleep. Does that feel like forever? • Do you drink coffee? Coke? Mountain Dew? Tea? Hot chocolate? Red Bull? • Alcohol does not make you sleep better. Reduces REM sleep. • Relaxation techniques before bed? Breathing? music? • If you can’t sleep, don’t just lie there! You’ll get frustrated and it will be even harder to fall asleep! Get up and do something boring.
What do sacred dance, meditation, and smoking pot have in common? Is there a natural human desire to try to alter one’s state of consciousness?
Psychoactive drugs • Stimulants • Depressants • Opiates • Psychedelics …All cause changes in conscious experience (perception, thinking, mood, memory) or behavior through biochemical processes
Psychoactive drugs • Stimulants – stimulate (speed up) CNS • Depressants – slow down CNS • Opiates – mimic natural pain relieving hormones, endorphins • Psychedelics – alter thought processes and perceptions
Where do alcohol, cocaine, crystal meth, oxycontin and marijuana belong?
chapter 5 Cocaine’s effect on the brain Blocks the brain’s reuptake of dopamine and norepinephrine, raising levels of these neurotransmitters. Results in over-stimulation of certain brain circuits and a brief euphoric high When drug wears off, depletion of dopamine may cause user to “crash.”
Then… why not dance?or meditate?or go search for ways to explore new experiences with your brain?