PSYC 440 Lecture Notes - Lecture 14: Slow-Wave Sleep, Non-Rapid Eye Movement Sleep, Circadian Clock
27 Apr 2018
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PSYC 440
Lecture 14 – Sleep & Depression
• Article
1. Look at process S and C
• Sleep
1. Normal Sleep Physiology
a. Measured electro-physiologically (e.g., brain activity with EEG, eye movements
with EDG, muscle activity).
2. Phases of sleep:
a. REM:
- 20%
b. nREM:
- 80%
i. Stage 1
ii. Stage 2
iii. Stage 3 and 4 (slow wave sleep)
3. PET
4. Brain activity during normal sleep:
a. Slow wave sleep:
- Decreased activity in many regions
b. REM Sleep:
- Overall looks more like being awake
c. Increases and decreased depend on the region (more decreases in the frontal)
• Sleep Regulation
1. Two-process model (both interact to regulate sleep):
a. Process C (internal clock):
- Circadian clock in the suprachiasmatic nucleus of the hypothalamus
b. Process S (sleep debt):
- Homeostatic (i.e. amount of sleep debt accumulated over the day)
2. Arousal:
a. Arousal is dimensional
• Serotonin
1. Serotonin varies during the day (i.e. levels are higher during wakefulness, lower
during slow wave sleep, and lowest during REM sleep):
a. One night of sleep deprivation increases serotonin:
- Study (meta-analysis of 61 studies):
i. Results:
Sleep deprivation impairs:
Executive functioning.
Sustained attention
Long-term memory
No effect on:
Intelligence
find more resources at oneclass.com
find more resources at oneclass.com
PSYC 440
Lecture 14 – Sleep & Depression
Ability to multitask
Impulsive decision-making
Intelligence
• Abnormal Sleep
1. Chronic insomnia:
a. Symptoms:
- Difficulty falling asleep, staying asleep, or early morning awakening despite
adequate opportunity to sleep.
- Must last 3 months
- Has daytime adverse consequences
b. Effects of insomnia:
- Cognitive impairments
- Physiological disturbances (e.g., weight gain, insulin dysregulation)
- Insomnia can cause mental health problems
- Mental health problems can lead to insomnia (and vice versa)
c. Risk factors for insomnia:
- Women
- Older age
- Shift working
- Mental health problems (40%)
d. Prevalence:
- 6% chronic insomnia
- >50% acute insomnia (i.e. common)
2. Hypersomnia:
a. Symptoms:
- Excessive sleep (during the day)
- Excessive sleepiness:
i. 8 hours of loss of sleep can negatively affect performance equivalent
to alcohol intoxication (i.e. loss of sleep affects performances)
• Mood Disorders (how sleep affects mental health, and vice versa)
1. Sleep disturbance as a core mechanism:
a. Risk factor:
- First onset & recurrence
- Precursor to both unipolar and bipolar depression
b. Common residual symptoms:
- More common among formerly depressed (45%) than never depressed (17%)
- Contribute to relapse
- Sleep complaints after remission in MDD
c. Changes in sleep architecture in MDD patients:
- Increased stage 1 sleep
- Decreased slow-wave sleep (stages 3 & 4; deep-sleep)
- Short REM-sleep latency (less time to get to REM):
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Lecture 14 sleep & depression: article, look at process s and c, sleep, normal sleep physiology, measured electro-physiologically (e. g. , brain activity with eeg, eye movements with edg, muscle activity), phases of sleep, rem: Stage 3 and 4 (slow wave sleep: pet, brain activity during normal sleep, slow wave sleep: Decreased activity in many regions: rem sleep: Overall looks more like being awake: increases and decreased depend on the region (more decreases in the frontal, sleep regulation, two-process model (both interact to regulate sleep), process c (internal clock): Circadian clock in the suprachiasmatic nucleus of the hypothalamus: process s (sleep debt): Intelligence: abnormal sleep, chronic insomnia, symptoms: Difficulty falling asleep, staying asleep, or early morning awakening despite adequate opportunity to sleep. Has daytime adverse consequences: effects of insomnia: Physiological disturbances (e. g. , weight gain, insulin dysregulation) Mental health problems can lead to insomnia (and vice versa) Insomnia can cause mental health problems: risk factors for insomnia:
