Sleep Chapter Notes | AP Psychology - Grade 11 PDF Download

Levels of consciousness

• Consciousness is how aware we are of our thoughts and environment.
• During wakefulness:
  • High awareness and quick responses.
  • Actively engage with the world around us.
  • Clearly notice and process stimuli.
• During sleep:
  • Less aware of surroundings.
  • Lower response to external stimuli.
  • Experience altered states of consciousness.

Circadian Rhythm and Disruptions

• Body's internal 24-hour clock, managed by the suprachiasmatic nucleus (SCN).
• Regulates when we feel sleepy or alert.
• Common disruptions:
  • Jet lag from traveling across time zones.
  • Shift work, especially with changing schedules.
  • Irregular sleep patterns.
  • Too much artificial light at night (e.g., from phones).
• Effects of disruptions:
  • Trouble falling or staying asleep, or staying awake.
  • Feeling confused or foggy-headed.
  • Changes in appetite or mood (e.g., feeling "hangry").
  • Feeling tired or physically unwell.

Stages of Sleep

Sleep has multiple stages, each with a specific role.

• Stage 1: Light sleep
  • Short phase, easy to wake up.
  • Hypnagogic sensations (e.g., feeling like you're falling).
• Stage 2: Intermediate sleep
  • Sleep spindles and K-complexes seen on EEG.
  • Body temperature drops.
• Stage 3: Deep sleep
  • Slow brain waves (slow-wave sleep).
  • Hard to wake up.
  • Important for physical recovery.

Deepest sleep happens earlier in the night.

REM Sleep
Unique stage where brain is active but body is paralyzed.

• Key features:
  • Rapid eye movements (eyes move under closed lids).
  • Muscle atonia (prevents acting out dreams).
  • Vivid, story-like dreams.
  • High brain activity, similar to being awake.
• Timing:
  • First REM period starts 90 minutes after falling asleep.
  • REM periods get longer later in the night, longest in the morning.
  • REM rebound happens if you miss REM sleep (more REM next time).

Theories of Dream Function

Dreams contribute to cognitive and emotional processing. Two key scientific theories include:

• Activation-Synthesis Theory: Dreams arise from the brain’s attempt to interpret random neural activity, creating narratives from this process.
• Memory Consolidation Theory: Dreams process daily experiences, integrating emotional memories and incorporating recent events.

Sleep’s Role in Memory

• Sleep is key for learning and forming memories.
• Brain processes and saves new information during sleep.
• Clears out unneeded data to make room for new learning.
• Memory processes during sleep:
  • Replays daytime experiences to strengthen them.
  • Builds stronger connections between brain cells.
  • Moves information to long-term memory storage.
• Restoration during sleep:
  • Clears waste from the brain.
  • Restocks neurotransmitters for brain communication.
  • Prepares brain for new learning.

Sleep Disorders and Effects

Sleep disorders harm daily life and health.

• Insomnia: Trouble falling or staying asleep.
• Narcolepsy: Extreme daytime sleepiness or sudden sleep attacks.
• Sleep apnea: Breathing stops and starts during sleep.
• REM sleep behavior disorder: Acting out dreams physically.
• Somnambulism: Sleepwalking.

Effects of sleep disorders:

• Cognitive impacts:
  • Shorter attention span.
  • Poor decision-making skills.
  • Memory issues.
• Physical effects:
  • Higher risk of accidents.
  • Weaker immune system.
  • Possible weight gain.
• Emotional consequences:
  • Mood swings and irritability.
  • Increased anxiety.
  • Higher risk of depression.