AP Psychology | Myers’ Unit 5 Part 1

Chapter 1: Consciousness and Dual Processing

Consciousness is our awareness of ourselves and our environment
Dual processing involves both conscious and unconscious awareness
Example of dual processing: riding a bike and conversing with a friend at the same time

During sleep, auditory cortex still responds to sound and we process information unconsciously
Sensitivity to sounds of crying babies or someone calling our name during sleep
Circadian rhythm is the body's internal clock that dictates when to be awake and when to be asleep
Two key chemical pathways synchronize the circadian rhythm: sunlight triggers the suprachiasmatic nucleus to decrease melatonin production in the morning, lack of light increases melatonin secretion at night

One sleep cycle lasts 90 minutes and consists of five stages
REM sleep is the stage where vivid dreams occur, muscles are relaxed but other parts of the body are active
Alpha waves are brainwaves when awake
Heart rate increases and neck muscles stretch during REM sleep

Stage 1: brief, experience hallucinations (false sensory experiences)
Stage 2: sleep spindles (rapid brain activity), sleep talking can occur
Stage 3: transitional stage, emits delta waves (slow and large brain waves)
Stage 4: deep sleep, emits more delta waves, hardest to wake someone up
REM sleep most resembles stage 1, characterized by heightened heart rate, rapid eye movement, and dreaming

Amount of sleep needed varies based on age, genetic makeup, culture, and technology
Effects of sleep loss: less productivity, irritability, weight gain, increased cortisol levels, increased hunger-arousing hormone ghrelin, decreased hunger-suppressing hormone leptin, suppressed immune cells, slowed reaction time

Insomnia: persistent issues with falling or staying asleep, quick fixes like alcohol or sleeping pills can make it worse, natural remedies include exercise, avoiding caffeine, maintaining regular sleep schedule
Narcolepsy: falling asleep spontaneously, can occur during activities
Sleep apnea: temporary cessation of breathing during sleep, can cause obesity, treated with devices to keep airway open
Night terrors: high arousal or appearance of terror during sleep, mostly occurs in children during stage 4

Dreams occur during REM sleep
Characteristics of dreams: heightened heart rate, rapid eye movement, response to dreams/hallucinations
Purpose of dreams not discussed in this chapter

Freud's interpretation of dreams to solve real-life problems is mostly wrong
Definition of a dream: a sequence of images, emotions, and thoughts processed by a sleeping person
Manifest content: the storyline of a dream
Interesting facts about dreams:
- We spend around six years of our life dreaming
- Some dreams can be so vivid that they can be confused with reality
- All dreams occur in REM sleep

Theory 1: Dreams satisfy our own wishes (Freud)
- Manifest content represents the remembered story of a dream
- Latent content represents the underlying meaning of a dream
- Dreams help us understand internal conflicts
Theory 2: Dreams help file away memories
- Dreams involve sifting and sorting through memories from the day
- Sleep and memory are linked
Theory 3: Dreams help develop and preserve neural pathways
- Dreaming stimulates the brain periodically
Theory 4: Dreams make sense of neural static (activation synthesis theory)
- Neural activity originating from the brainstem causes dreams
Theory 5: Dreams reflect cognitive development
- Dreams increase in complexity with age
- Children under 9 years of age have dreams more similar to slideshows

REM rebound: occurs when a person has less REM sleep and then gets to REM sleep faster in the next sleep cycle
Humans and most mammals can experience REM rebound
Fish don't experience REM sleep and their behavior is less influenced by learning