Chapter 5 Flashcards
Consciousness
Awareness of internal & external events
Vegetative state
Eyes open & close but don’t react to things around them
Coma
Eyes stay shut
Suprachiasmatic Nucleus (SCN)
Located in the hypothalamus
Function: “Biological clock”
- SCN sends signals to PINEAL gland
- p gland increases production of melatonin hormone as light decreases
Hormone Melatonin
Makes you feel sleepy
What suppresses melatonin?
Blue light from smart phones, etc suppress melatonin
Circadian rhythm
The Sleep cycle:
- biological activity that rise & fall in a 24-hour cycle
Circa = about
Diem = 1 day
Biological clock correct itself according to environmental cues but can function w/out them
What does extended sleep deprivation cause?
It imposes severe physical & psychological consequences
I.e1 getting cold when you don’t have enough sleep
I.e2 lower cognitive performance
Why do we need sleep?
Evolutionary perspective: conserve our energy & stay away from predators
Cognitive perspective: help us think better
Electro-encephalograph or EEG
Records brain activity
Electro-myograph or EMG
Records muscle activity
Electro-oculograph EOG
Records eye movements
Brain waves
Summed activity of neurons measured by EEG
- brain waves differ in frequency (Hz = number of peaks per second) and amplitude (peak height)
5 stages of sleep cycle: Awake & Alert
fast (frequency) & small (amplitude) alpha waves (8-13 Hz)
5 stages of sleep cycle: Stage 1 NREM Alpha
Alpha (8-13 Hz) then Theta waves (4-7 Hz)
- “just dozing off”
- hypnagogic imagery
-myoclonic jerks
5 stages of sleep cycle: Stage 2 NREM Theta (sleep spindles; K-complexes)
Still sensitive to external world
- Sleep spindle & K-complexes - slows heart rate, lower body temps, decrease eye movement
5 stages of sleep cycle: Stages 3-4 NREM Delta
Called Slow wave sleep or delta wave sleep (1-4 Hz)
- deepest stage of sleep
- Needed to feel refreshed in the morning
- suppressed by alcohol
5 stages of sleep cycle: REM
Cycle reverses but enters REM instead of stage 1
- rapid side-to-side eye movement
- brain waves resembles waking brain
- no muscle tension (mostly paralyzed)
- dreaming occurs
Summary of sleep cycle
Sleep cycle Summary
- Sleep cycle repeats 4-5 times per night abt 90 mins per cycle
- REM sleep gets longer; Non-REM sleep (stages 1-4) gets shorter
Lucid dreaming
Experience of becoming aware that you’re dreaming
- possibility of controlling our dreams
Why do we dream? Theories of dreaming: REM Sleep
- dreaming as wish fulfillment
Freud proposed that people fulfill wishes in dreams - activation -synthesis theory
brain attempts to make sense out of random brain
activity during REM sleep - neurocognitive theory
Psychoactive drugs
Selectively alter neurotransmitter activity in brain
- blocking reuptake
- mimicking neurotransmitters produced internally
- some opioids mimic body’s own “natural pain killers” aka ENDORPHINS
