Consciousness

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 ā€œalive.ā€ 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 inputĀ 

LSD - a potent hallucinogenā€”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 ā€œhighā€ 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 asleepĀ 
  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