guest lecture - dr. jade wu

sleep

what is sleep?

• low state of consciousness

• relaxed body position

• involuntary

• crucial for life

awake stage

EEG shows alpha and beta waves

low amplitude, high frequency

stage N1

restful wake

EEG shows theta

higher amplitude, slower frequency

stage N2

light sleep

producedural learning and memory consolidation

sleep spindles and K complex - brain practices things you learned in the day

stage N3

deep sleep

EEG shows delta waves, slow

brain releases growth and sex hormones, tissue repair and memory

fleshes out toxins

REM

dream sleep

EEG shows theta and beta waves

active and dynamic stage

emotional regulation, memory consolidation

sleep cycles

not 90 mins long

cycles are not the same length or across the night

stage N3 is 20%, occurs earlier bc brain prioritizes this recovery

REM mostly happens in later part of night

sleep adjusts its architecture depending on what you’re experiencing

people with depression get REM sleep earlier in the night

REM sleep is an active brain/body state

higher body temp, heart and breathing rate

muscle atonia = “paralyzed”

genital arousal

theories for why we dream

1. activation-synthesis

2. wish fulfillment

3. information processing and emotion regulation

4. threat simulation

activation-synthesis theory

cortex creates a coherent story from the brain’s experience of electrical signals and external stimuli

wish fulfillment theory

repressed urges and desires are expressed, sometimes symbolically

information processing and emotion regulation theory

brain sorts through recent experiences to organize what’s useful and what’s not

threat simulation theory

dreams simulate potentially dangerous situations so you can practice dealing with them

REM parasomnia - sleep disorders during REM sleep

sleep paralysis, hallucinations

nightmares

REM sleep behaviour disorder - acting out your dreams

narcolepsy - extreme sleepiness during the day, sleep attacks

non-REM parasomnias - sleep disorders that occur outside REM

sleepwalking - common in children

sleep terrors - someone appears to be awake and really distressed

sleep eating, talking, driving, sex

why does sleep go wrong?

1. not enough sleep

2. not at the right time

3. drugs

4. genes, physiology, anatomy

5. trauma, stress, mental health conditions

not enough sleep

7-9 hrs for adults

if not enough: worse focus, emotion regulation, poor decision making, physical metabolism, brain and heart health

drugs

e.g. caffeine, alcohol, cannabis, prescription and over the counter meds

melatonin - natural hormone we already have

too much melatonin can trigger too much of the darkness trigger and cause worse sleep

trauma, stress, mental health conditions

with PTSD, higher chance of nightmares, insomnia, parasomnia, sleep-related disoders