Sleep and Dreams Flashcards
Circadian rhythm
- biological clock (controlled by hypothalamus).
- Provides approximate schedule for physical processes
Suprachiasmatic nucleus (SCN)
(in hypothalamus) sensitive to changes in light
How does the Suprachiasmatic nucleus (SCN) react to little light?
SCN tells pineal gland to secrete melatonin
Melatonin
Causes sleepiness
How does the Suprachiasmatic nucleus (SCN) react to more light?
SCN tells pineal gland to stop secreting melatonin
What is seasonal effective disorder?
It is clinical depression in the Winter that goes away in the Summer
What is the effect of artificial lighting on our melatonin production?
breaks down melatonin.
What is non-rapid eye movement (N-REM)
non dreaming sleep
Stage 1 of N-REM
- similar to drowsiness
- Hypnic or hypnagogic jerk
- Hypnagogic hallucinations
Stage 2 of N-REM
– true sleep – reductions in heart rate and muscle tension
Stage 3/4 of N-REM
- deeply asleep, hard to awaken, disoriented when awakened
- Growth hormones released from pituitary
What is Rapid eye movement (REM) Sleep
- “Paradoxical sleep”
- Eyes move back and forth
- Heart rate, blood pressure, breathing – rapid or irregular
- Dreams
- Sleep paralysis
Effects of Sleep Deprivation
- Irritability, difficulty concentrating
- Slower healing, reduced immune system activity
- Lower production of growth hormone
- Impairment of memory formation
- Increased risk of depression
- Increased risk of obesity
- Selective deprivation of stage 3/4- muscle and joint pain
What was Cohen et al.’s (2009) study?
exposed Ps to cold virus, measured average amount of sleep per night
Evolutionary/adaptive theory
protection – not out and vulnerable to predators in the dark
Restorative theory
Supports growth
Information processing theory
- supports cognitive processes
- Restores and rebuilds memories
- Supports creative thinking
Why do we dream? (Freud)
to satisfy our own unconscious wishes
Why do we dream? (Information processing)
memories (external events)
Why do we dream? (Preserving neural pathways)
brain stimulation
Why do we dream? (Activation synthesis)
brain’s internally generated signals (internal events)
i. What is a hypnagogic jerk?
occurs when one feels a sensation of falling or floating weightlessly
ii. What is a hypnagogic hallucination
Sensory experiences that occur without a sensory stimulus, occurs shortly after falling asleep
a. What is the meaning of “paradoxical sleep?”
the body is internally aroused, with waking-like brain activity, yet asleep and externally calm
i. When is growth hormone released from the pituitary gland?
Stage 3, an hour after you first fall asleep
b. What is sleep paralysis?
Your awake but not awake
