AP Psychology: Unit 3

Sleep, Perception & Sensation; Modules 16, 17, 20, 21, 22, 23

NREM 1

Initial stage characterized by hypnagogic sensations and hallucinations.

NREM 2

A deeper relaxation, characterized by sleep spindles and EEG patterns showing more synchronized brain activity

NREM 3 and 4

Deep sleep, featuring slow delta waves. Hardest stage to wake from; crucial for physical restoration. Growth hormones are released.

REM

Motor cortex is active but brainstem blocks messages, associated with vivid dreams. Plays a key role in memory consolidation, especially for skills and information learned during the day.

What’s another word for REM sleep?

Paradoxical sleep

What does REM sleep stand for?

Rapid Eye Movement sleep

What are the roles of dreams?

• consolidate memories

• process emotions

• express deep desires

• practice confronting potential dangers

Activation Synthesis Theory

Theory that dreams are the brain’s way of making sense of random neural activity

Consolidation Theory

Theory that dreams help process and solidify memories and experiences from the day

Insomnia

Difficulty falling or staying asleep

Narcolepsy

Sudden and uncontrollable “sleep attacks”, often directly into REM sleep

REM Sleep Behavior Disorder

Disorder where people act our their dreams due to lack of muscle paralysis during REM sleep

• Mostly older men

Sleep Apnea

Breathing repeatedly stops and starts, disrupting sleep and causing excessive daytime sleepiness.

Somnambulism

Sleepwalking that typically occurs during deep NREM sleep, where individuals walk or perform tasks while still asleep

Suprachiasmatic Nucleus

A pair of small, specialized clusters of about 10,000 neurons each located in the anterior hypothalamus of the brain, directly above the optic chiasm that communicates with the pineal gland to secrete melatonin

Locus Coeruleus

A tiny, pigmented nucleus located deep in the dorsolateral pons of the brainstem that is activated heavily during stress and autonomic responses

Sensation

The brain receives input from the sensory organs —> nerve impulses

Perception

The brain makes sense out of the input from sensory organs

Bottom-Up Processing

Begins with sensory input, building perception from the smallest pieces of sensory information

Top-Down Processing

Uses prior knowledge, expectations, and experiences to interpret sensory information

Schemas

Mental frameworks that help organize and interpret information

What do we have schemas for?

People, faces, objects, and events that shape our perceptions

Attention

The mental focus on specific stimuli while ignoring others

Selective attention

Focusing on one thing among many distractions

Sensation

The process by which our sensory receptors and nervous system receive and represent stimuli from our environment

Absolute Threshold

The minimum intensity of a stimulus that can be detected 50% of the time

Just-Noticeable Difference (JND or Difference Threshold)

The smallest detectable change in a stimulus, indicating the sensitivity of our sensory perception.

Weber’s Law

The principle that the size of the JND is proportional to the intensity of the stimulus

Sensory Adaptation

When constant exposure to a stimulus leads to decreased sensitivity over time as the sensory receptors become less responsive.