Sleep & Emotions Flashcards
Ultradian rhythms
Repeat more than once a day
Infradian rhythms
Repeat less frequently than once a day
Biological rhythms
Regular fluctuations in any living process
Free-running rhythm
Circadian cycles without entrainment, close to 24hrs
Entrainment
Synchrony with the day/night cycle by using a zeitgeber
Zeitgeber
A cue used to synchronize with day/night cycles
Suprachiasmatic nucleus (SCN)
Where biological clock is located (in hypothalamus above optic chiasm), lesions eliminate circadian rhythms
Pineal gland
Secretes melatonin at night, sensitive to light in amphibians and birds
Retinohypothalamic pathway
Formed by some retinal ganglion cells, carries light information from the eye to the SCN to entrain biological rhythms
What happens at puberty in terms of circadian rhythm?
It shifts so teens get up later
Electroencephalographs (EEG)
Record electrical activity in the brain that can be used to classify levels of arousal and sleep
Rapid-eye-movement sleep (REM)
Small amplitudes and fast EEG waves similar to an awake person
Stage 1 sleep
- More time in alpha rhythm
- Smaller amplitude waves and irregular frequency
- Sharp waves called vertex spikes
- Heart rate slows, muscles relax, eyes roll about
- Lasts a few mins
Stage 2 sleep
Sleep spindles
Stage 3 (slow wave) sleep
-Delta waves (large amplitude, very slow)
-Non-rem dreams occur
Awake
Desynchronized EEG or beta activity
Typical young adult sleep
- 7-8 hours
- Half of sleep is stage 2
- 20% is REM
- Cycles last 90-110 mins
-Earlier cycles have more stage 3 - Later cycles have more REM
Activation-synthesis theory
Experiences in REM sleep are random results of neurons that happen to get activated
Unilateral sleep
Only one hemisphere enters SWS at a time
Infant sleep facts
-More
-Shorter cycles
-More REM sleep (50%)
Elderly sleep facts
- Total sleep time declines
- Increased awakenings
- Stage 3 sleep declines
- Half as much by 60, gone by 90
Sleep deprivation
- Increased irritability
- Difficulty concentrating
- Episodes of disorientation
Sleep recovery
- Night 1: More stage 3 sleep at the expense of stage 2
- Nights 1 and 2: REM sleep shows a great increase and is more intense
Why sleep?
Conserves energy and helps animals avoid predators when they’re most vulnerable. Also has a restorative function
Sleep and memory consolidation
- Improves retention
- Perceptual skills improved by period of REM
- Memory tasks and motor skills benefit from SWS
Forebrain system
Generates SWS
Brainstem system
Activates the forebrain to wakefulness
Pontine system
Triggers REM sleep
Hypothalamic system
Coordinates the other three systems
Basal forebrain
Generates constant SWS activity at forebrain, becomes active at sleep onset and releases GABA
Anesthetics
Stimulate GABA receptors in tuberomamillary nucleus
The pons
Locus coeruleus, triggers REM sleep
Narcolepsy
Sleep attacks, lost 90% of orexin neurons
Cataplexy
A sudden loss of muscle tone leading to collapse
Orexin neurons
Neurons in the hypothalamus that project to other sleep system centres
Sleep paralysis
Pontine centre imposes muscle paralysis
Sleep enuresis
(bed wetting) associated with SWS
Somnambulism
(sleep walking) Occurs in stage 3 SWS
REM behaviour disorder (RBD)
- Organized behaviour in a person who appears to be asleep
- Usually after age 50, more common in men
- May be followed by Parkinson’s symptoms
Sleep-onset insomnia
Trouble falling asleep, caused by situational factors
Sleep-maintenance insomnia
Difficulty staying asleep, caused by drugs or neurological factors
Emotion
A subjective mental state that is usually accompanied by distinctive behaviours as well as involuntary physiological changes
Sympathetic nervous system
Fight or flight
Parasympathetic nervous system
Relax and recuperate
Folk psychology theory
Feelings trigger autonomic reaction
James-Lange theory
Autonomic reaction triggers feeling
Cannon Bard theory
Simultaneous autonomic reaction and feeling
Darwin
Suggested that expressions of emotions are universal
What do emotions do?
Act as motivational programs that evolved to coordinate responses to solve adaptive problems
Plutchiks 8 basic emotions
- Joy/sadness
- Affection/disgust
- Anger/fear
- Expectation/surprise
- Sometimes contempt/embarrassment
Ekmans 8 facial expressions of emotion
- Anger
- Sadness
- Happiness
- Fear
- Disgust
- Surprise
- Contempt
- Embarrassment
Superficial facial muscles
Attach between points of facial skin.
Innervated by the facial nerve
Deep facial muscles
Attach to bone, produce larger movements like chewing.
Innervated by the motor branch of the trigeminal nerve (V)
Facial feedback hypothesis
Sensory feedback from our facial expressions affects our mood
James Papez subcortical circuit of emotion
Noticed emotional changes from specific sites of brain damage
Amygdala
Involved in fear mediation and emotional learning
Different emotions activate ____ regions of the brain
Different
Testosterone
Increases aggression in man species but unclear in humans
Serotonin
Inhibits aggression
Ventromedial hypothalamus (VMH)
Involved in aggressive behaviour
Maternal aggression
Aggression in mothers defending their nest or offspring controlled partially by VMH
Stress triggers release of…
- Cortisol from adrenal cortex
- Epinephrine and norepinephrine from adrenal medulla
Stress immunization
Mild stress early in life improves resiliency to later stress
Epigenetic regulation
Represents a change in the expression of the gene rather than a change in the encoding region of the gene
Psychosomatic medicine
Emphasizes the role of psychological factors in disease
Health psychology
Emphasizes the psychological influences such as social factors of cognitive-behavioural factors on health and illness
Psychoneuroimmunology
- Studies the interactions of the immune system with hormonal and neurological systems
- Stressful periods suppress the immune system
Adrenal steroid hormones
Released during stress, suppress the immune system allowing all resources to be used for immediate survival
