Sleep Patterns & Theories

Biological rhythms and sleep

• circadian rhythm - the biological clock; regular bodily rhythms that occur on a 24hr cycle

• Alpha waves - the relatively slow brain waves of a relaxed, awake state

• Delta waves - the large, slow brain waves associated with deep sleep

• Suprachiasmatic nucleus - a pair of cell clusters in the hypothalamus that controls circadian rhythm; modify feelings of sleepiness

• Sleep - periodic natural loss of consciousness

NREM 1 - first 15 minutes when you fall asleep: breathing slows, brain wave activity becomes more irregular

NREM 2 - the next 20 minutes after NREM1: sleep deeper, the brain has bursts of wave activity

NREM 3 - the next 30 minutes after NREM 2: slow, constant delta-wave activity in your brain, hard to wake up from

REM sleep - a recurring sleep stage during which vivid dreams commonly occur

Why we sleep:

1. protection

2. recovery

3. memory consolidation

4. creativity

5. growth

Psychoactive Drugs

Psychoactive Drug - any chemical substance that alters perceptions, moods, mental processes, emotions, etc

• not all are illegal: alcohol, caffeine, medications

Tolerance - continuous use of a psychoactive drug leads to neuroadaptation

Addiction - a compulsive craving for a drug despite harmful consequences

Withdrawal - experiencing physical symptoms from not using a drug

Classifications

• depressants - reduce neural activity and slow down body functions

• stimulants - excite neural activity and speed up body functions

• hallucinogens - drugs that distort perception and can create sensory experiences without sensory input

Amphetamines - a group of synthetic drugs (substituted phenethylamines) that stimulate the reticular formation in the brain and cause a release of stored norepinephrine

Methamphetamine increases the amount of dopamine in the brain, which is involved in movement, motivation, and reinforcement of rewarding behaviors

Nicotine - stimulant (acetylcholine agonist), elevated mood, increased physical arousal, highly addictive

Cocaine - causes a euphoric high that heightens the senses, increases energy and mental alertness, and boosts confidence, making them feel more “alive.” This is because cocaine stimulates the brain's pleasure receptors, dopamine, and serotonin

Ecstasy (MDMA) - a synthetic drug that acts as a stimulant and hallucinogen. It produces an energizing effect, distortions in time and perception

Hallucinogens - drugs that distort perception and can create sensory experiences without sensory input

LSD - a potent hallucinogen—that is, a drug that can alter a person's perception of reality and vividly distort the senses

Marijuana/THC -the psychoactive substance that produces the “high” associated with smoking marijuana and can also lead to central nervous system depression

SSRIs - commonly prescribed to treat major depressive and anxiety disorders

Dreams

What are Dreams?

• hallucinations

• tend to be vivid and bizarre and negative

Content of dreams

• can be influenced by recent events

• often relate to commonly performed tasks

• can be culturally influenced

Parallel Processing - while part of our mind is dreaming another part is monitoring our environment

• REM rebound - the compensatory increase of the frequency, depth, and intensity of REM sleep following sleep deprivation or significant stressors

Dream theories:

1. Wish Fulfillment - to fulfill our wishes from the subconscious; Freud

2. To remember - there are certain types of memory consolidation that only can happen while asleep

3. Reverse learning - to forget; helps us to drop unnecessary brain connections

4. Conditional activation - keep our brains working

5. PIRT primitive instinct rehearsal - to practice fight or flight response

6. to heal - dreaming helps us to make things less psychologically painful

7. problem-solving - our brains work more creatively while asleep

8. neural activation - to make sense of random neural activity

9. cognitive development - top-down control of our dream content; reflects knowledge and understanding

Manifest content - remembered storyline of a dream

Latent content - underlying meaning of a dream