Lesson 13 - Unit 1 Flashcards
Sleep
Consciousness
Is your awareness of the outside world and yourself, including your own mental processes, thoughts, feelings, behaviour and perceptions.
Sleep and wakefulness are 2 types of consciousness
Circadian Rhythm
Your 24hr biological clock in our brain that regulates cycles of alertness and sleepiness by responding to light changes in our environment.
Sleep/Wake Cycle
Is a circadian rhythm, where there are many stages of sleep that can be identified by EEG patterns
NREM 1 sleep stage
As you begin to fall asleep, you fall into a semi-wakeful, dreamlike awareness state known as a hypnagogic state - you feel relaxed, fail to respond to the outside stimuli and may experience hallucinations.
NREM 2 sleep stage
Continuation of light sleep. Your breathing rate, temperature, heart rate, and muscle tension all start to decline. (10-20min)
NREM 3 sleep stage
A deeper form of sleep. You stay in for about 20-40 mins. No eye movements and the body is relaxed.
REM Sleep
- Marked by rapid eye movements, high-frequency brain waves and dreaming. Brain activity is similar to NREM1
- REM sleep is called paradoxical sleep, where your body can also become aroused.
- Your muscles are almost completely paralyzed because the brainstem blocks messages down from the motor cortex.
Hypnagogic State / Sensations
A transitional stage between wakefulness and sleep, in which sensory perceptions can be experienced
Paradoxical Sleep
REM sleep produces the same brain frequency waves as wakefulness, but paradoxically, you are in your most relaxed state. fMRI is best for recording sleep activity.
Sleep Behaviours
closed eyes, little movement, recumbent posture, and reduced responsiveness to stimulation
REM Rebound
Activation
Allows the brain to compensate for lost sleep. During REM rebound, a person needs less sleep to get into REM sleep, because REM is so important to the brain’s health and function
Synthesis Theory
Dreams are purely a consequence of random neural firing from the brainstem (they are meaningless). Your frontal lobe interprets whatever it can from the neural activation.
- This random firing and subsequent interpretation is why dreams do not often make sense.
Jet Lag
Messes up your circadian rhythm. It may cause you to sleep at the wrong time or have poor sleep.
- Making you feel sluggish and irritable
Shift Work
Plays with your biological rhythms (circadian rhythm). Has negative impacts on your social relationships, productivity and mental health (can be linked to physical disease)
Consolidation Theory
Dreams help us to restore and rebuild memories of the day’s experiences (consolidation of memories)
- Research has shown that people demonstrate better memory or recently learnt material after sleeping.
Insomnia
The inability to fall asleep/stay asleep
- Results in day time fatigue and impaired functioning
- Causes stress, disruptions of biological rhythms…
- Sedatives can be prescribed or other approaches like meditation before bed can be helpful
Narcolepsy
A condition where an awake person suddenly and uncontrollably falls asleep (often directly into REM sleep)
- Main cause = impairment in the regulation of REM sleep
- Patients benefit from naps, drug therapy (stimulants/antidepressants)
Sleep Apnea
A sleep disorder characterized by temporary stops of breathing that wake up the person repeatedly during the night.
- Usually the result of obstruction/collapse of air passages (often in obese people) - weight loss and side sleeping can help
- Treatment = positive pressure pump that provides a steady flow of air through a face mask
Somnambulism
(Sleepwalking) (often in children)
- Occurs during NREM3.
- Trips out of bed/complex activities happen and usually, the person does not remember anything when they wake up.
- Links to genetic predisposition and stress
- episodes in adults are usually linked to prior sleep deprivation and increased stress
REM Sleep Behavioural Disorder (RBD)
- When people talk, yell, gesture, flail or leap out of bed during their REM stage.
- Many say they were where being chased/attacked in their dreams.
- Mostly in middle-aged men
- Cause = structural deterioration of the brainstem - the area responsible for immobilizing their body during REM
- It is typical that other neurodegenerative disorders appear after RBD develops (Parkinsons)
